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1
Li, Cheng, und Yanjun Liu. „Selling Forestry Revolution: The Rhetoric of Afforestation in Socialist China, 1949–61“. Environmental History 25, Nr. 1 (19.11.2019): 62–84. http://dx.doi.org/10.1093/envhis/emz081.
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Abstract This article attempts to cast doubt on prior scholarship regarding Maoist environmental rhetoric regarding forestry, which has tended to characterize it as destructive, militaristic, and irrationally extractive. Against this simplistic portrayal of Maoist rhetoric concerning Chinese forestry and Mao Zedong’s attitudes toward nature, this article demonstrates that the rhetoric of forestry and environment in general during Mao’s period is scientific, rational, and even constructive regarding tree planting. To demonstrate the rational and premeditated aspect of socialist forestry and environmental history, the article first explores the speeches and writings of Japan and Germany educated Liang Xi, probably the most important forester in early socialist China, who advocated tree planting as a way of tackling the problem of the scarcity of trees. During the early 1950s, his firm belief that tree planting could solve the problems of the Yellow River clashed with hydrologists who also aspired to solve China’s environmental challenges. Using newspaper reports from the People’s Daily, the article then examines the rhetoric of the “Greening the Motherland” campaign launched by Mao in 1956. During this campaign, Mao pushed the Yellow River’s tree-planting initiative to a national scale, thanks largely to the foresters’ concerted efforts of persuasion. This nationwide campaign, in concert with the new regime's state-building efforts, required foresters to instill knowledge of tree planting in a broad range of people at the grassroots level as well as to strategically integrate it within the socialist revolutionary and global environmental discourse.
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Zhou, Qianyi, Zhaohong Jiang, Xin Zhang, Qing Lai, Yiming Li, Fei Zhao und Zhong Zhao. „Tree age did not affect the leaf anatomical structure or ultrastructure of Platycladus orientalis L. (Cupressaceae)“. PeerJ 7 (29.10.2019): e7938. http://dx.doi.org/10.7717/peerj.7938.
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Tree aging is a new research area and has attracted research interest in recent years. Trees show extraordinary longevity; Platycladus orientalis L. (Cupressaceae) has a lifespan of thousands of years. Ancient trees are precious historical heritage and scientific research materials. However, tree aging and tree senescence have different definitions and are poorly understood. Since leaves are the most sensitive organ of a tree, we studied the structural response of leaves to tree age. Experiments investigating the leaf morphological structure, anatomical structure and ultrastructure were conducted in healthy P. orientalis at three different ages (ancient trees >2,000 years, 200 years < middle-aged trees <500 years, young trees <50 years) at the world’s largest planted pure forest in the Mausoleum of the Yellow Emperor, Shaanxi Province, China. Interestingly, tree age did not significantly impact leaf cellular structure. Ancient P. orientalis trees in forests older than 2,000 years still have very strong vitality, and their leaves still maintained a perfect anatomical structure and ultrastructure. Our observations provide new evidence for the unique pattern of tree aging, especially healthy aging. Understanding the relationships between leaf structure and tree age will enhance the understanding of tree aging.
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Zhou, Qianyi, Zhaohong Jiang, Xin Zhang, Tian Zhang, Hailan Zhu, Bei Cui, Yiming Li, Fei Zhao und Zhong Zhao. „Leaf anatomy and ultrastructure in senescing ancient tree, Platycladus orientalis L. (Cupressaceae)“. PeerJ 7 (11.04.2019): e6766. http://dx.doi.org/10.7717/peerj.6766.
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Platycladus orientalis L. (Cupressaceae) has a lifespan of thousands of years. Ancient trees have very high scientific, economic and cultural values. The senescence of ancient trees is a new research area but is poorly understood. Leaves are the primary and the most sensitive organ of a tree. To understand leaf structural response to tree senescence in ancient trees, experiments investigating the morphology, anatomy and ultrastructure were conducted with one-year leaves of ancient P. orientalis (ancient tree >2,000 years) at three different tree senescent levels (healthy, sub-healthy and senescent) at the world’s largest planted pure forest in the Mausoleum of Yellow Emperor, Shaanxi Province, China. Observations showed that leaf structure significantly changed with the senescence of trees. The chloroplast, mitochondria, vacuole and cell wall of mesophyll cells were the most significant markers of cellular ultrastructure during tree senescence. Leaf ultrastructure clearly reflected the senescence degree of ancient trees, confirming the visual evaluation from above-ground parts of trees. Understanding the relationships between leaf structure and tree senescence can support decision makers in planning the protection of ancient trees more promptly and effectively by adopting the timely rejuvenation techniques before the whole tree irreversibly recesses.
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Chen, Youping, Feng Chen und Heli Zhang. „A Tree-Ring-Based Precipitation Reconstruction since 1760 CE from Northeastern Tibetan Plateau, China“. Atmosphere 12, Nr. 4 (24.03.2021): 416. http://dx.doi.org/10.3390/atmos12040416.
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Hydroclimatic conditions and related water resources change in the Tibetan Plateau is one of the main concerns for future sustainable development in China. This study presents a 254-year precipitation reconstruction from August of the previous year to June of the current year for the northeastern Tibetan Plateau based on tree-ring width data of tree-ring cores of Picea crassifolia from three sampling sites. The precipitation reconstruction explained 51.4% of the variance in instrumental precipitation during the calibration period 1958–2013. Dry periods with precipitation below the 254-year average value occurred during 1848–1865, 1873–1887, 1898–1923, and 1989–2003, and wet periods (precipitation above the mean) occurred during 1769–1785, 1798–1833, 1924–1938, 1957–1968, and 2004–2013. Spatial correlation analyses with the precipitation gridded dataset showed that our reconstruction contains some strong regional-scale precipitation signals for the upper Yellow River Basin. Our precipitation reconstruction also agreed in general with other dendroclimatic precipitation reconstructions from surrounding regions. In addition, reconstructed precipitation changes were consistent with the streamflow variation of the Yellow River.
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Li, Z. Y., Z. P. Dong, Z. M. Hao und J. G. Dong. „First Report of Elm Yellows Subgroup 16SrV-B Phytoplasma Infecting Chinese Tulip Tree in China“. Plant Disease 96, Nr. 7 (Juli 2012): 1064. http://dx.doi.org/10.1094/pdis-03-12-0281-pdn.
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Chinese tulip tree (Liriodendron chinensis) is native to China and is planted all around the country as an ornamental tree. In July of 2011, some Chinese tulip trees with typical phytoplasma symptoms were found in Baoding City, Hebei Province, China. Symptoms included yellowing of leaves, slow decline, little leaves, and death of entire plants. To confirm phytoplasma infection of these plants, total DNA was extracted from 100 mg of fresh leaf midribs collected from leaves of nine symptomatic and eight asymptomatic plants with a plant DNA extract kit (Tiangen, Beijing, China) according to the manufacturer's protocols. Using 16S rRNA phytoplasma universal primer pairs P1/P7 followed by R16F2n/R16R2, a nest PCR was carried out (1,2). The results showed that the phytoplasma was only detected in symptomatic samples by nested PCR, while the asymptomatic were negative. An approximate 1.2-kb specific fragment was obtained from the DNA of nine symptomatic plants, but no product was amplified from the leaves of eight healthy ones. The amplified products were cloned and sequenced. The sequence was deposited in GenBank Data Libraries under Accession No. JQ585925 and shared the highest homology of 99% with Puna chicory flat stem phytoplasma (GenBank Accession No. JN582266), Apricot leaf roll phytoplasma (GenBank Accession No. FJ572660), Jujube witches'-broom phytoplasma (GenBank Accession No. AY197661), and other elm yellows group phytoplasmas by BLAST analysis with that of other phytoplasmas from GenBank. Meanwhile, the sequence data was analyzed by iPhyClassifier software and the result showed that the 16S rDNA F2nR2 fragment was identical (similarity coefficient 1.00) to the reference patterns of 16Sr group V, subgroup B (GenBank Accession No.AB052876) (3). Combining the BLAST analysis in GenBank and the analysis of iPhyClassifier, we classified the phytoplasma causing Chinese tulip tree yellow leaves disease into subgroup 16SrV-B. To our knowledge, this is the first report of the 16SrVB group phytoplasmas infecting Chinese tulip tree in China. References: (1) I. M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998. (2) I. M. Lee et al. Int. J. Syst. Evol. Microbiol. 54:337, 2004. (3) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.
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Tian, Yan, Masoomeh Ghobad-Nejhad, Shuang-Hui He und Yu-Cheng Dai. „Three new species of Aleurodiscus s.l. (Russulales, Basidiomycota) from southern China“. MycoKeys 37 (03.08.2018): 93–107. http://dx.doi.org/10.3897/mycokeys.37.25901.
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Three new species of Aleurodiscus s.l. with corticioid basidiomata are described and illustrated from southern China based on morphological evidence and phylogenetic analyses of ITS and nrLSU sequence data. Aleurodiscusbambusinus was collected from Jiangxi Province on bamboo and is distinct by having a compact texture, simple-septate generative hyphae, abundant acanthophyses, basidia with acanthophysoid appendages and smooth basidiospores. Aleurodiscusisabellinus was collected from Yunnan Province on both angiosperm wood and bamboo and is distinct by having soft basidiomata with yellow to yellowish-brown hymenophore, yellow acanthophyses, simple-septate generative hyphae and smooth basidiospores. Aleurodiscussubroseus was collected from Guangxi Autonomous Region and Guizhou Province on angiosperm wood and is distinct by having pinkish basidiomata when fresh, clamped generative hyphae, clavate acanthophyses and echinulate basidiospores. In the phylogenetic tree, A.bambusinus and A.isabellinus were nested within the A.cerussatus group, whilst A.subroseus was clustered with A.wakefieldiae. An identification key to 26 species of Aleurodiscus s.l. in China is provided.
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Li, Zhi-Zhong, Shuang Wu, Chun-Yu Zhou, Yan Liu, Guang-Wan Hu, Samuli Lehtonen, Qing-Feng Wang und Jin-Ming Chen. „Ottelia fengshanensis, a new bisexual species of Ottelia (Hydrocharitaceae) from southwestern China“. PhytoKeys 135 (30.10.2019): 1–10. http://dx.doi.org/10.3897/phytokeys.135.38531.
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Ottelia fengshanensis, a new species (Hydrocharitaceae) from southwest China is here described and illustrated. Comparing its morphological features to putative close relatives O. guanyangensis, it has 3–4 flowers (vs. 2–5) each spathe, hexagonal-cylindric fruit, white styles (vs. yellow), green leaves (vs. dark green) and fruit tiny winged (vs. winged obviously). Molecular phylogenetic investigation of four DNA sequences (ITS, rbcL, trnK5’ intron and trnS-trnG) and the Poisson Tree Processes model for species delimitation (PTP) analysis, further resolves O. fengshanensis as a new species that is close to O. guanyangensis with distinct support.
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Gou, Xiaohua, Fahu Chen, Meixue Yang, Gordon Jacoby, Jianfeng Peng und Yongxiang Zhang. „A comparison of tree-ring records and glacier variations over the past 700 years, northeastern Tibetan Plateau“. Annals of Glaciology 43 (2006): 86–90. http://dx.doi.org/10.3189/172756406781812438.
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AbstractThe ecological environment of the headwater area of the Yellow River, west China, is seriously deteriorating because of the harsh natural environment, weakened ecological systems and intensified human activities as well as regional climate changes. Forests and glaciers coexist in this area. Glaciers in the area have retreated over the last decade because of climate change. Most glaciers on the Tibetan Plateau (TP) tend to retreat during warm intervals and advance during cold intervals. Tree-ring records provide an important index for examining past climate changes. A total of 139 core samples from 97 living cypresses (Juniperus przewalskii) in the central region of the Yellow River headwater area, the Animaqin mountains, northeastern TP, were sampled from three sites that are close to each other. The chronologies were developed using the ARSTAN program. Analyses indicate that these tree-ring width records reflect the summer maximum temperature of the study area over the past 700 years. The tree-ring records and the glacier advances recorded by terminal moraines are compared. Inferred summer maximum temperatures suggest three cold periods during the Little Ice Age, around AD1500, 1700 and 1850. These cold intervals are consistent with the glacier moraine record from the region.
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Li, Yanzhong, Kang Liang, Changming Liu, Wenbin Liu und Peng Bai. „Evaluation of different evapotranspiration products in the middle Yellow River Basin, China“. Hydrology Research 48, Nr. 2 (26.05.2016): 498–513. http://dx.doi.org/10.2166/nh.2016.120.
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Actual evapotranspiration (ETa) is a central process in the climate system and a nexus of the water and energy cycles. This study assesses the hydrological performance of the four categories of ETa products (i.e., land surface models (LSMs), reanalysis, model tree ensemble, and diagnostic models (DMs)) for use in the middle Yellow River Basin (MYRB) using water balance methods. The results show the following. (1) The water storage changes significantly at annual scale and cannot be neglected when calculating the reference ETa by the water balance methods. (2) ETa from LSMs, considering the precipitation input, exhibits the best performance in capturing the reference ETa variation. The MET ETa (AETJUNG), based on eddy covariance, has fair performance with a small underestimation, followed by the DMs, including MODIS and ZhangKe. Poor performance is found in reanalysis ETa (JRA55), due to overestimations precipitation and radiation. (3) The reference ETa showed decreased and then increased trend. ETa from the LSMs-Noah model captures the trend well, followed by the LSMs-variable infiltration capacity model. Our results are not only meaningful for better understanding ETa variability in the MYRB, but also significant for improving global ETa products models' performance in semi-arid and semi-humid regions.
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Wu, Xianbo, und Xiaofeng Hui. „Economic Dependence Relationship and the Coordinated & Sustainable Development among the Provinces in the Yellow River Economic Belt of China“. Sustainability 13, Nr. 10 (13.05.2021): 5448. http://dx.doi.org/10.3390/su13105448.
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This study uses the mutual information method to study economic dependence among the provinces in the Yellow River Economic Belt, constructs the core dependence structure through the maximum spanning tree method, and uses the rolling window method to observe the changes in the dependence structure from a dynamic point of view. It has been found that there are extensive economic links among the nine provinces in the Yellow River Economic Belt, but that the degree of economic dependence varies greatly in different time periods. When economic development and the capital market are overheated, the interregional dependence is stronger, while the dependence decreases when economic development is in a state of contraction or when the total demand is relatively reduced. In addition, the phenomenon of geographical clustering of economic dependence is not obvious among provinces in the Yellow River Economic Belt. Most of the provinces maintain strong economic dependence with the economically developed provinces, and the economically developed provinces also maintain strong economic ties with one another. Finally, the implementation of the Yellow River Economic Belt strategy strengthens the economic links between the less developed provinces and the other provinces in the region, and promotes coordinated and sustainable development in the region.
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He, Chang, Jun Jin, Ying Wang, Zhaohui Ma, Songjie He und Mingyuan Li. „Polybrominated diphenyl ethers, dechlorane plus, and polychlorinated biphenyls in tree bark near the upper Yellow River, China“. Environmental Toxicology and Chemistry 33, Nr. 8 (28.05.2014): 1732–38. http://dx.doi.org/10.1002/etc.2621.
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JIAN, SI-PENG, RONG DAI, JUN GAO und BANG FENG. „Cantharellus albus, a striking new species from Southwest China“. Phytotaxa 470, Nr. 2 (03.11.2020): 133–44. http://dx.doi.org/10.11646/phytotaxa.470.2.2.
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A new species, Cantharellus albus, was collected from southwestern China and described with both morphological and molecular characters. It differs from other species of Cantharellus by its smooth white pileus, white hymenophore, and white stipe, the latter turning yellow after bruising. The phylogenetic tree inferred from the combined dataset of three DNA fragments, namely large subunit ribosomal RNA gene (LSU), RNA polymerase II second largest subunit (rpb2), and translation elongation factor 1-alpha gene (tef1), indicated that the new species is distinct from other species of Cantharellus and is a member of sect. Flavobrunnei within the subgenus Parvocantharellus.
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SO, JENNY F. „Scented Trails: Amber as Aromatic in Medieval China“. Journal of the Royal Asiatic Society of Great Britain & Ireland 23, Nr. 1 (Januar 2013): 85–101. http://dx.doi.org/10.1017/s1356186313000023.
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Amber has been known since antiquity in Europe, made into pendants, and used for perfume containers in large quantities since the first millennium bce. It is a naturally occurring fossilized tree (a certain kind of northern pine) resin, composed primarily of carbon-hydrogen-oxygen (C10H16O). It is rather soft (Mohs hardness 2.0–2.5), hence easy to carve, and possesses a resinous luster when polished. Its colours range from transparent to translucent deep orange-red to brown and sometimes a more opaque yellow. Solid amber has no smell, but when powdered it gives off an agreeable aroma. When warmed or burned it has a characteristic pinewood fragrance. It softens at about 150°C and, if heated above 200°C, it will break down to give an “oil of amber” and a black residue. In his Historia naturalis (XXXVII), Pliny the Elder considers its scent when heated to be the most reliable proof of real amber.
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Long, J. Y., Y. H. Chen und J. R. Xia. „First Report of a Group 16SrI Phytoplasma Associated with Amaranthus hypochondriacus Cladodes in China“. Plant Disease 95, Nr. 7 (Juli 2011): 871. http://dx.doi.org/10.1094/pdis-03-11-0219.
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Amaranthus spp. are cultivated worldwide as leafy vegetable, cereal, and ornamentals. In China, stems and leaves of Amaranthus hypochondriacus L. are used as a vegetable (2). In July 2010, sporadic amaranth plants exhibiting symptoms of cladodes and spica proliferation were observed in a vegetable garden near Foshan, Guangdong, China. Stem samples were collected from two symptomatic and two asymptomatic plants. Total DNA was extracted with a modified cetyltrimethylammonium bromide (CTAB) method (1). Nested PCR with a combination of phytoplasma-specific universal primer pairs (P1/P7 and R16F2n/R16R2) amplified 16S rDNA sequences with the expected size of 1.2 kb from all samples of symptomatic amaranth plants, but not from the asymptomatic plants (3). Nested PCR products yielded identical AluI, HhaI, HpaII, HaeIII, KpnI, MseI, RsaI, Sau3AI, and TaqI restriction fragment length polymorphism (RFLP) profiles with chinaberry witches'-broom phytoplasma (16SrI-B subgroup), but different from peanut witches'-broom phytoplasma (16SrII group), jujube witches'-broom phytoplasma (16SrV group), and paulownia witches'-broom phytoplasma (16SrI-D subgroup). Nested PCR products were purified, cloned in pMD18-T Simple Vector (TaKaRa, Dalian, China), and sequenced. The 16S rDNA sequences were identical and deposited in GenBank (Accession No. JF323034). GenBank BLASTn analysis indicated that the amaranth extracts showed as high as 99% sequence identity with the members of 16SrI group phytoplasmas, including those associated with arecanut yellow leaf disease (FJ998269) and aster yellow AY-27 (HM467127). A polygenetic tree was constructed using MEGA 4.0 based on the 16S rDNA sequences of amaranth cladode phytoplasma and other phytoplasmas belonging to 16SrI phytoplasma group. In phylogenetic analysis, the sequences clustered on a single branch with members of 16SrI-B subgroup in the tree. Therefore, the phytoplasma was classified in subgroup 16SrI-B. To our knowledge, this is the first report of a subgroup 16SrI-B phytoplasma associated with diseased A. hypochondriacus in China. References: (1) E. Angelini et al. Vitis 40:79, 2001. (2) M. Costea et al. Econ. Bot. 57:646, 2003. (3) I. M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998.
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Liu, Yulin, Zhedong Huang, Yan Ao, Wei Li und Zhixiang Zhang. „Transcriptome Analysis of Yellow Horn (Xanthoceras sorbifolia Bunge): A Potential Oil-Rich Seed Tree for Biodiesel in China“. PLoS ONE 8, Nr. 9 (11.09.2013): e74441. http://dx.doi.org/10.1371/journal.pone.0074441.
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Wu, Jiaxing, Song Zhang, Sagheer Atta, Caixia Yang, Yan Zhou, Francesco Di Serio, Changyong Zhou und Mengji Cao. „Discovery and Survey of a New Mandarivirus Associated with Leaf Yellow Mottle Disease of Citrus in Pakistan“. Plant Disease 104, Nr. 6 (Juni 2020): 1593–600. http://dx.doi.org/10.1094/pdis-08-19-1744-re.
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During biological indexing for viruses in citrus trees, in a collection of Symons sweet orange (SSO) (Citrus sinensis L. Osbeck) graft inoculated with bark tissues of citrus trees from the Punjab Province in Pakistan, several SSO trees exhibited leaf symptoms of vein yellowing and mottle. High-throughput sequencing by Illumina of RNA preparation depleted of ribosomal RNAs from one symptomatic tree, followed by BLAST analyses, allowed identification of a novel virus, tentatively named citrus yellow mottle-associated virus (CiYMaV). Genome features of CiYMaV are typical of members of the genus Mandarivirus (family Alphaflexiviridae). Virus particles with elongated flexuous shape and size resembling those of mandariviruses were observed by transmission electron microscopy. The proteins encoded by CiYMaV share high sequence identity, conserved motifs, and phylogenetic relationships with the corresponding proteins encoded by Indian citrus ringspot virus (ICRSV) and citrus yellow vein clearing virus (CYVCV), the two current members of the genus Mandarivirus. Although CYVCV is the virus most closely related to CiYMaV, the two viruses can be serologically and biologically discriminated from each other. A reverse-transcription PCR method designed to specifically detect CiYMaV revealed high prevalence (62%) of this virus in 120 citrus trees from the Punjab Province, Pakistan, where the novel virus was found mainly in mixed infection with CYVCV and citrus tristeza virus. However, a preliminary survey on samples from 200 citrus trees from the Yunnan Province, China failed to detect CiYMaV in this region, suggesting that the molecular, serological, and biological data provided here are timely and can help to prevent the spread of this virus in citrus-producing countries.
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Cui, Zhi Yi, Xiao Mei Deng, Ru Chun Xi, Rui Ping Li und Jia Xin Hu. „Nutrient Limiting Factors in Red-Yellow Soil from Different Parent Rocks at Oil-Tea Forest Land in the South-Central Region of China“. Applied Mechanics and Materials 694 (November 2014): 568–75. http://dx.doi.org/10.4028/www.scientific.net/amm.694.568.
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Nutrient limiting factors in main soils from oil tree forest land of the south-central region in Hunan Province were assessed by employing the systematic approach developed by Agro Services International and selecting Sorghum as indicate plant in order to evaluate their nutrient status and limiting factors. The results of soil testing showed that the four oil tree forest land soils were low in organic matter, N, P, K was severely deficient, but the available S and Fe were sufficient, the deficiency of Ca, Mg, B, Zn and Mo were rather common. In the tested oil tree Camellia forest land soils, the larger capacity of adsorption and fixation belonged to K, Zn, Mn in Quaternary red soil and to B in Sandstone soil, while the capacity of adsorption and fixation of K, B in Phyllite soil land and P, Mn, Zn in Granite soil was weak. The results of pot experiment showed that its nutrient deficient degree was in the order of N>P>K>B>Mo>Mn in Granite soil; that was in the order of K>P>N> Zn in Sandstone soil; that was in the order of P>N>K>Cu>Zn>Mn>Mo>S in Phyllite soil; that was in the order of N>P>K>Zn>Mo>Cu>B in Quaternary red soil. So P, N and K were the main nutrient limiting factors of oil tree forest land soils in Hunan province, and then followed by Zn, B and Mo. Next field experiments should be focused on the balanced fertilization of N, P, K, and B, Zn, Mo. Moreover, much attention should be paid to make up Ca and Mg.
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Wenyue, Ma, Zhang Ya, Wang Chong, Liu Shuangqing und Liao Xiaolan. „A new disease of strawberry, fruit rot, caused by Geotrichum candidum in China.“ Plant Protection Science 54, No. 2 (10.02.2018): 92–100. http://dx.doi.org/10.17221/76/2017-pps.
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A new disease of strawberry (Fragaria ananassa Duch.) was discovered in the Lianqiao strawberry planting base in Shaodong County, in Hunan Province, China. In the early disease stage, leaves showed small black spots surrounded by yellow halos, while in the late stage, a white fluffy layer of mold appeared. Fruits were covered with a white layer of mold. The symptoms were observed using in vitro inoculation experiments. After the spray-inoculation of stabbed leaves, small black spots surrounded by yellow halos occurred on leaves, with no clear boundary between diseased and healthy areas. In the late stage, disease spots gradually expanded and a white fluffy layer of mold formed under humid conditions. Unstabbed leaves had almost no disease occurrence after spray-inoculation. After the spray-inoculation of stabbed fruits, by the late stage, a dense white layer of mold formed. According to Koch’s postulates, the isolated strain was verified as a pathogen. The pathogenic strain, designated SDLQ16, was isolated from diseased fruit by dilution method and tentatively identified as G. candidum based on the culture characteristics, morphologies, physio-biochemical analysis, and phylogenetic analysis of the rDNA-ITS sequence. The fungus was able to grow on different culture mediums, with a broad range of nutrition. The colonies on PDA medium were raised and pale white, with a neat edge and visible hyphae. The hyphae were friable but the spores were developing. Basal hyphae rapidly grew close to the medium to 3.2–4.2 µm in diameter, with septa and forked branches at acute angles. The solitary or beaded spores with smooth surfaces were 3.5–7.5 µm in length and 3.5–4.5 µm in width. This strain was able to gelatin liquefaction, proteolysis, grease, peptonised milk, urea, and so on. The pathogenicity on strawberry from strong to weak was: fruit > leaf > stem. A BLAST algorithm was used to query SDLQ16’s rDNA-ITS sequence (cloned and deposited as GenBank number KU373122) against the NCBI database, and it was located in the Acinetobacter sp. branch of a phylogenetic tree. SDLQ16 was most closely related to Geotrichum candidum ATCC34614 (GQ4580314.1), with a sequence similarity of 99%.
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Li, Lingyu, Yiming Chen, Yingli Ma, Zhong Wang, Tao Wang und Yinfeng Xie. „Optimization of Taxol Extraction Process Using Response Surface Methodology and Investigation of Temporal and Spatial Distribution of Taxol in Taxus mairei“. Molecules 26, Nr. 18 (09.09.2021): 5485. http://dx.doi.org/10.3390/molecules26185485.
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Taxus mairei is an important source for industrial extraction of taxol in China. However, the standard and steps of extraction are currently not uniform, which seriously affects the taxol yield. In the present study, the influence of four factors (methanol concentration, solid-liquid ratio, ultrasonic extraction temperature, and ultrasonic extraction time) on the taxol yield was successively explored in T. mairei. A response surface methodology (RSM) was used to optimize the extraction process based on the single-factor experiments above. The optimal conditions were as follows: methanol concentration was 90%, solid-liquid ratio was 1:15 (g/mL), ultrasonic extraction temperature was 40 °C and ultrasonic extraction time was 60 min. Moreover, the twigs and needles from T. mairei with different tree ages were treated by the optimum extraction process, which further revealed temporal and spatial distribution of taxol in the reproducible tissues. Interestingly, the taxol content was relatively higher in needles of T. ‘Jinxishan’ (a cultivar from T. mairei with yellow aril, FY), but was less in FY twigs. The accumulation of taxol in twigs and leaves of females (with red aril, FR) was significantly higher than that of males (M); however, the content showed a decreasing trend with the increasing tree ages. Therefore, it is suitable to increase the proportion of female trees especially the FY leaves as raw materials for the industrial production of taxol from T. mairei, and the tree ages should be better controlled at 3–7 years.
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Wang, Hongxing, Ruibai Zhao, Huaiwen Zhang, Xianmei Cao, Zhaotong Li, Ze Zhang, Jinling Zhai und Xi Huang. „Prevalence of Yellow Leaf Disease (YLD) and its Associated Areca Palm Velarivirus 1 (APV1) in Betel Palm (Areca catechu) Plantations in Hainan, China“. Plant Disease 104, Nr. 10 (Oktober 2020): 2556–62. http://dx.doi.org/10.1094/pdis-01-20-0140-re.
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Yellow leaf disease (YLD) is an economically important disease affecting betel palm in several countries, the cause of which remains unclear despite associations with putative agents, including phytoplasmas. In this study, we screened the potential casual agents associated with YLD in Hainan, China using next-generation sequencing and revealed the association of areca palm velarivirus 1 (APV1) with the YLD-affected palm. The complete genome of the APV1-WNY isolate was determined to be 17,546 nucleotides in length, approximately 1.5 kb longer than the previously reported APV1_HN genome. Transmission electron microscopy showed that APV1 particles are flexuous and filamentous, a typical morphology of species in the Closteroviridae family. Comparison of symptomatic and symptomless tree populations showed a strong association between APV1 and YLD. APV1 was detected in Pseudococcus sp. mealybugs sampled from YLD-affected trees in many locations, suggesting that mealybugs are a potential transmission vector for APV1. Although further studies are needed to confirm a causal relationship, these results provide timely information for the prevention and management of YLD associated with APV1.
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Dosmann, Michael Sean, und Jeffery K. Iles. „Cold Stratification Improves Germination of Katsura Tree“. HortScience 32, Nr. 3 (Juni 1997): 447F—448. http://dx.doi.org/10.21273/hortsci.32.3.447f.
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Katsura tree (Cercidiphyllum japonicum Sieb. & Zucc.), an ornamental tree native to Japan and China, is valued for its broad pyramidal form and apricot-yellow fall leaf color. Another species, Cercidiphyllum magnificum (Nakai) Nakai, exists, but is rarely encountered outside of wild populations, except in a pendulous form. Propagation of katsura is by seed germination and softwood cuttings, although little information exists in the scientific literature regarding either method of propagation. To determine conditions for optimal seed germination, we subjected C. japonicum seed to a factorial combination of moist stratification and exposure to light. Two seed lots were obtained from the Arnold Arboretum of Harvard Univ., accessions 1150-67 and 882. Half of the seeds in each lot were moist stratified in petri dishes on filter paper for 8 days at 3.5°C. All seeds then were germinated at 25°C with either a daily photoperiod of 15 hr or complete darkness. Those samples not exposed to light were placed in a light-tight container. Germination was defined as the average percentage of seeds per treatment combination that showed the emergence of a radicle. Unstratified seeds germinated at 44.7% over both seed lots. Moist stratification increased germination to 92.0% and 56.7% for 1150-67 and 882, respectively. Light did not affect germination for either seed lot. Optimal seed germination conditions for C. magnificum will be determined in future studies. We have shown that moist stratification of katsura seeds improves germination and recommend this method as a means of promoting seed germination.
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Cai, Z. Y., Y. X. Liu, G. H. Li, Y. F. Wang und M. Zhou. „First Report of Alternaria alternata Causing Black Leaf Spot of Rubber Tree in China“. Plant Disease 99, Nr. 2 (Februar 2015): 290. http://dx.doi.org/10.1094/pdis-09-14-0954-pdn.
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We first reported Alternaria heveae (E.G. Simmons ) to be the pathogen that caused black leaf spot of rubber tree (Hevea brasiliensis Muell. Arg) in Heikou county in July 2014 (1). Black leaf spots that resembled the symptoms caused by A. heveae were observed on the leaves of rubber trees of the whole propagule collection nursery in Jingping County (22°68′ N and 103°05′ E) of Yunnan Province. Black foliar spots (0.1 to 2 mm in diameter) surrounded by a yellow halo with lesions slightly sunken on the leaf surface were observed. To confirm whether the disease was caused by the same pathogen, 5-mm2 sections were removed from the leading edge of the lesion and were surface-sterilized in 75% ethanol, air-dried, plated on potato carrot agar (PCA), and incubated at 28°C in the dark. Colonies of the fungus on PCA had round margins and little aerial mycelia with gray-black coloration after 6 days of growth on PCA (2). Medium brown conidia were found to be in short chains of two to eight spores, ovoid, obclavate, and obpyriform, with or without a short conical or cylindrical-shaped apical beak. Conidia ranged from 22.5 to 67.5 μm long (mean 39.9 μm) × 10 to 15 μm wide (mean 12.5 μm; 100 colodia were measured), with three to six transverse septa and zero to three longitudinal or oblique septa. Morphological characteristics matched the descriptions of A. alternata [(Fries) Keissler] (4).The ITS1-5.8S-ITS2 region of one single-spore isolate, Ah02JP1, was amplified with primers ITS1 and ITS4. The PCR product was sequenced directly and deposited in GenBank (Accession No. KM111289). A BLAST search of the GenBank database revealed 100% similarity with A. alternata isolates KJ829535.1, KJ677246.1, and KF813070.1. Therefore, the pathogen was identified as A. alternata on the basis of its morphological characteristics and ITS sequence. Pathogenicity of a representative isolate, Ah02JP1 was confirmed using a field rubber tree inoculation method. Three rubber plants (the clone of rubber tree Yunyan77-4) were grown to the copper-colored leaf stage. Leaves were spray-inoculated (104 conidia per milliliter spore suspension) until drops were equally distributed using a manual pressure sprayer. Three rubber plants sprayed with sterile distilled water were used as controls. After inoculation, the plants were covered with plastic bags to maintain high relative humidity. The plastic bags were removed 2 days post-inoculation (dpi), and the plants were monitored daily for symptom development. Five days post-inoculation, spots similar to the original ones seen on the field trees developed on all inoculated leaves, while control leaves remained symptomless. A. alternata was re-isolated from spray-inoculated leaves, confirming Koch's postulates. A. alternata has been reported as the causal agent of leaf blight of rubber tree in India, which initially appeared as minute spots on leaves and enlarged with the growth of the leaves (3). However, in the present study, the symptoms (black leaf spots) remained small over time after inoculation. To our knowledge, this is the first report of A. alternata on rubber tree in China. Correct identification of pathogens is essential for disease management strategies. This report will establish a foundation for the further study of Alternaria alternata to address the disease effectively. References: (1) Z. Y. Cai et al. Plant Dis. 98:1011, 2014. (2) E. Mirkova. J. Phytopathol. 151:323, 2003. (3) C. B. Roy et al. J. Plantation Crops 34:499, 2006. (4) T. Y. Zhang. Page 32 in: Flora Fungorum Sinicorum, Vol. 16: Alternaria. Science Press, Beijing, 2003.
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CHEN, ZENING, JIANPING YU, GERNOT VOGEL, SHENGCHAO SHI, ZHAOBIN SONG, YEZHONG TANG, JIA YANG, LI DING und CANGSONG CHEN. „A new pit viper of the genus Trimeresurus (Lacépède, 1804) (Squamata: Viperidae) from Southwest China“. Zootaxa 4768, Nr. 1 (30.04.2020): 112–28. http://dx.doi.org/10.11646/zootaxa.4768.1.7.
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The white-lipped tree viper, Trimeresurus albolabris Gray, is one of the most common species of the genus Trimeresurus with a wide distribution from India eastwards to China and southwards to Indonesia. However, this species was previously split into five geographical clades with significant genetic divergence. Recent surveys in Yingjiang County, Yunnan Province, China resulted in the discovery of one cryptic species of the subgenus Trimeresurus. Combining molecular, morphological and ecological data, we describe it as a new species Trimeresurus caudornatus sp. nov. The new species differs from other Trimeresurus species by a combination of the following characteristics: (1) Head and body generally dark green, postocular stripes absent in both genders, upper labials light green; (2) ventrolateral stripe faint green yellow, present on the first row of DSR in both genders; (3) iris golden yellow in both genders; (4) dorsal tail mostly dark red, lateral and ventral green; an orange red stripe along the ventral part of the tail; (5) DSR 21/22 –21–15, VEN 161–163, SC 52–72; (6) first upper labial partially fused to the nasal. The new species was shown to be a strongly supported monophyletic group (BPP 100%) and sister to T. septentrionalis. The uncorrected pairwise distances of mitochondrial gene Cytb between the new species and other species of the subgenus Trimeresurus, ranging from 0.059 (T. septentrionalis) to 0.134 (T. kanburiensis).
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Li, B. X., T. Shi, X. B. Liu, C. H. Lin und G. X. Huang. „First Report of Rubber Tree Stem Rot Caused by Fusarium oxysporum in China“. Plant Disease 98, Nr. 7 (Juli 2014): 1008. http://dx.doi.org/10.1094/pdis-01-14-0004-pdn.
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Rubber tree (Hevea brasiliensis) is an important crop in tropical regions of China. In October 2013, a new stem rot disease was found on cv. Yunyan77-4 at a rubber tree plantation in Hekou, Yunnan Province. There were about 100 plants, and diseased rubber trees accounted for 30% or less. Initially, brown-punctuate secretion appeared on the stem, which was 5 to 6 cm above the ground. Eventually, the secretion became black and no latex produced from the rubber tree bark. After removing the secretion, the diseased bark was brown putrescence, but the circumambient bark was normal. Upon peeling the surface bark, the inner bark and xylem had brown rot and was musty. The junction between health and disease was undulate. On the two most serious plants, parts of leaves on the crown were yellow, and the root near the diseased stem was dry and puce. The pathogen was isolated and designated HbFO01; the pathogenicity was established by following Koch's postulates. The pathogen was cultivated on a potato dextrose agar (PDA) plate at 28°C for 4 days. Ten plants of rubber tree cv. Yunyan77-4 were selected from a disease-free plantation in Haikou, Hainan Province, and the stem diameter was about 7 cm. The bark of five plants was peeled, and one mycelium disk with a diameter of 1 cm was inserted into the cut and covered again with the bark. The other five plants were treated with agar disks as controls. The inoculation site was kept moist for 2 days, and then the mycelium and agar disk were removed. On eighth day, symptoms similar to the original stem lesions were observed on stems of inoculated plants, while only scars formed on stems of control plants. The pathogen was re-isolated from the lesions of inoculated plants. On PDA plates, the pathogen colony was circular and white with tidy edges and rich aerial hyphae. Microscopic examination showed microconidia and chlamydospores were produced abundantly on PDA medium. The falciform macroconidia were only produced on lesions and were slightly curved, with a curved apical cell and foot shaped to pointed basal cell, usually 3-septate, 16.2 to 24.2 × 3.2 to 4.0 μm. Microconidia were produced in false heads, oval, 0-septate, 6.2 to 8.2 × 3.3 to 3.8 μm, and the phialide was cylindrical. Chlamydospores were oval, 6.4 to 7.2 × 3.1 to 3.8 μm, alone produced in hypha. Morphological characteristics of the specimen were similar to the descriptions for Fusarium oxysporum (2). Genomic DNA of this isolate was extracted with a CTAB protocol (4) from mycelium and used as a template for amplification of the internal transcribed spacer (ITS) region of rDNA with primer pair ITS1/ITS4 (1). The full length of this sequence is 503 nt (GenBank Accession No. KJ009335), which exactly matched several sequences (e.g., JF807394.1, JX897002.1, and HQ451888.1) of F. oxysporum. Williams and Liu had listed F. oxysporum as the economically important pathogen of Hevea in Asia (3), while this is, to our knowledge, the first report of stem rot caused by F. oxysporum on rubber tree in China. References: (1) D. E. L. Cooke et al. Fungal Genet. Biol. 30:17, 2000. (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual, 2006. (3) T. H. Williams and P. S. W. Liu. A host list of plant diseases in Sabah, Malaysia, 1976. (4) J. R. Xu et al. Genetics 143:175, 1996.
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Du, Ping, Tian-Xu Cao, Ying-Da Wu, Meng Zhou und Zhan-Bo Liu. „Two new species of Hymenochaetaceae on Dracaena cambodiana from tropical China“. MycoKeys 80 (05.05.2021): 1–17. http://dx.doi.org/10.3897/mycokeys.80.63997.
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Two new wood-rotting fungi in the family Hymenochaetaceae, Fulvifomes dracaenicolasp. nov. and Hymenochaete dracaenicolasp. nov., are described and illustrated from tropical China based on morphological characteristics and molecular data. It is worth to mention that both of them grow on Dracaena cambodiana which is a kind of angiosperm tree distributed in tropical regions. F. dracaenicola is characterised by perennial, pileate, triquetrous basidioma with yellowish brown fresh pores which becoming honey yellow with silk sheening upon drying, a dimitic hyphal system in trama and monomitic in context, and subglobose basidiospores measuring 4.8–5 × 4–4.1 μm. H. dracaenicola is characterised by annual, resupinate basidioma with a clay buff hymenophore, a dimitic hyphal system, absence of tomentum and cortex, presence of subulate setae, absence of cystidia, presence of cystidioles and simple hyphidia, and oblong ellipsoid basidiospores measuring 5.2–5.8 × 2.5–2.8 µm. The phylogenetic analyses based on ITS + nLSU rDNA sequences confirm the placement of two new species respectively in Fulvifomes and Hymenochaete. Phylogenetically closely related species to the two new species are discussed.
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Huang, Xuan, und Liangjun Zhao*. „New Golden Leaf Cultivar of Celtis julianae (`Golden Phoenix') and Its Primary Research“. HortScience 39, Nr. 4 (Juli 2004): 895D—895. http://dx.doi.org/10.21273/hortsci.39.4.895d.
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As well as investigating physiological characteristics of the new yellow cultivar of Celtis julianae—`Golden Phoenix' (Julian hackberry, which originally distributed in south of China, is important environmental plant, because there are numerous hairs on surfaces of the leaf, which can absorb dust and clean the air. Julian hackberry is deciduous big tree, more than 25 meters in high, with deep green leaf, red flower and orange fruit, blossoming in April.), differences in leaf color between the new cultivar and the normal Celtis julianae were evaluated. The new cultivar is a natural seed mutant from some cultivated seedlings of Celtis julianae found in 2001. It has golden yellow leaf, average color is Yellow-Green150A mensurating by English Color Card, is significantly more different than those of the normal. It can normally growing but slowly, with smaller plant-size and shorter internode than common plant. The new cultivar's leaf contains less chlorophyll than the normal, but same carotenoid. Its net photosynthetic rate is lower than that of Julian hackberry common cultivates in full sunlight. Shading of leaf to 50% sunlight decreases chlorophyll content and photosynthetic rate compared with full sunlight and sharper in photosynthetic, resulting in deepen green color. Leaves of the new cultivar show higher values of lightness and yellow-green as compared with other normal. Shoot multiplication frequency was highest on woody plant medium containing 1.5 mg 6-BA(benzyladenine)/ml, producing 6 shoots from a single explant, but these are some troubles to root.
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Cai, Chuner, Kai Gu, Hui Zhao, Sophie Steinhagen, Peimin He und Thomas Wichard. „Screening and verification of extranuclear genetic markers in green tide algae from the Yellow Sea“. PLOS ONE 16, Nr. 6 (01.06.2021): e0250968. http://dx.doi.org/10.1371/journal.pone.0250968.
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Over the past decade, Ulva compressa, a cosmopolitan green algal species, has been identified as a component of green tides in the Yellow Sea, China. In the present study, we sequenced and annotated the complete chloroplast genome of U. compressa (alpha-numeric code: RD9023) and focused on the assessment of genome length, homology, gene order and direction, intron size, selection strength, and substitution rate. We compared the chloroplast genome with the mitogenome. The generated phylogenetic tree was analyzed based on single and aligned genes in the chloroplast genome of Ulva compared to mitogenome genes to detect evolutionary trends. U. compressa and U. mutabilis chloroplast genomes had similar gene queues, with individual genes exhibiting high homology levels. Chloroplast genomes were clustered together in the entire phylogenetic tree and shared several forward/palindromic/tandem repetitions, similar to those in U. prolifera and U. linza. However, U. fasciata and U. ohnoi were more divergent, especially in sharing complementary/palindromic repetitions. In addition, phylogenetic analyses of the aligned genes from their chloroplast genomes and mitogenomes confirmed the evolutionary trends of the extranuclear genomes. From phylogenetic analysis, we identified the petA chloroplast genes as potential genetic markers that are similar to the tufA marker. Complementary/forward/palindromic interval repetitions were more abundant in chloroplast genomes than in mitogenomes. Interestingly, a few tandem repetitions were significant for some Ulva subspecies and relatively more evident in mitochondria than in chloroplasts. Finally, the tandem repetition [GAAATATATAATAATA × 3, abbreviated as TRg)] was identified in the mitogenome of U. compressa and the conspecific strain U. mutabilis but not in other algal species of the Yellow Sea. Owing to the high morphological plasticity of U. compressa, the findings of this study have implications for the rapid non-sequencing detection of this species during the occurrence of green tides in the region.
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Cai, Z. Y., Y. X. Liu, G. X. Huang, M. Zhou, G. Z. Jiang, H. J. Mu, H. Q. Li und G. H. Li. „First Report of Alternaria heveae Causing Black Leaf Spot of Rubber Tree in China“. Plant Disease 98, Nr. 7 (Juli 2014): 1011. http://dx.doi.org/10.1094/pdis-01-14-0065-pdn.
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Rubber tree (Hevea brasiliensis Muell. Arg.) is an important industrial crop of tropical areas for natural rubber production. In October 2013, foliar spots (0.1 to 0.4 mm in diameter), black surrounded by a yellow halo, and with lesions slightly sunken were observed on the rubber tree leaf in a growing area in Heikou County of Yunnan Province. Lesion tissues removed from the border between symptomatic and healthy tissue were surface sterilized in 75% ethanol and air-dried, plated on PDA plates, and incubated at 28°C with alternating day/night cycles of light. The pathogen was observed growing out of many of the leaf pieces, and produced abundant conidia. Colonies 6.1 cm in diameter developed on potato carrot agar (PCA) after 7 days, with well-defined concentric rings of growth. Colonies on PCA were composed of fine, dark, radiating, surface and subsurface hyphae. Conidia produced in PCA culture were mostly solitary or in short chains of 2 to 5 spores, long ovoid to clavate, and light brown, 40 to 81.25 × 8 to 20 μm (200 colonies were measured), with 3 to 6 transverse septa and 0 to 2 longitudinal or oblique septa. Morphological characteristics were similar to those described for Alternaria heveae (3,4). A disease of rubber tree caused by Alternaria sp. had been reported in Mexico in 1947 (2). DNA of Ah01HK13 isolate was extracted for PCR and sequencing of the ITS region with ITS1 and ITS4 primers was completed. From the BLAST analysis, the sequence of Ah01HK13 (GenBank Accession No. KF953884), had 97% similarity to A. dauci, 96% identical to A. macrospora (AY154701.1 and DQ156342.1, respectively), indicating the pathogen belonged to Alternaria genus. According to morphological characteristics, this pathogen was identified as A. heveae. Pathogenicity of representative isolate, Ah01HK13 was confirmed using a field rubber tree inoculation method. Three rubber plants (the clone of rubber tree Yunyan77-4) were grown to the copper-colored leaf stage and inoculated by spraying spore suspension (concentration = 104 conidia/ml) to the copper-colored leaves until drops were equally distributed on it using manual pressure sprayer. Three rubber plants sprayed with sterile distilled water were used as controls. After inoculation, the plants were covered with plastic bags. The plastic bags were removed after 2 days post-inoculation (dpi) and monitored daily for symptom development (1). The experiment was repeated three times. The typical 0.1 to 0.4 mm black leaf spots were observed 7 dpi. No symptoms were observed on control plants. A fungus with the same colony and conidial morphology as A. heveae were re-isolated from leaf lesions on inoculated rubber plants, but not from asymptomatic leaves of control plants, fulfilling Koch's postulates. Based on these results, the disease was identified as black spot of rubber tree caused by A. heveae. To our knowledge, this is the first report of A. heveae on rubber tree in China. References: (1) Z. Y. Cai et al. Microbiol Res. 168:340, 2013. (2) W. J. Martin. Plant Dis. Rep. 31:155, 1947. (3) E. G. Simmons. Mycotaxon 50:262, 1994. (4) T. Y. Zhang. Page 111 in: Flora Fungorum Sinicorum: Alternaria, Science Press, Beijing, 2003.
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Lou, B. G., Y. D. Xu, C. Sun und X. M. Lou. „First Report of Leaf Blight on Duying Caused by Phyllosticta anacardiacearum in China“. Plant Disease 93, Nr. 5 (Mai 2009): 546. http://dx.doi.org/10.1094/pdis-93-5-0546b.
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Duying (Elaeocarpus glabripetalus Merr.; Elaeocarpaceae) is widely cultivated as an ornamental tree of commercial importance in southern China. From 2003 to 2008, severe outbreaks of Duying leaf blight occurred in the Hangzhou area, Zhejiang Province. Disease incidence was greater than 20% and mainly infected young leaves and shoots in the spring and autumn. Severely infected leaves and shoots died and eventually led to branch dieback. The overall growth decline of affected trees occurs over 4 to 6 years before tree death. Infection symptoms are characterized by grayish, round, semicircular- or irregular-shaped spots (5 mm to 5 cm long) with dark brown borders and the appearance of black, granular pycnidia within the dead leaf tissues. The primary infection zones are commonly observed on the leaf margins and apices, are brown, up to 2 mm in diameter, and often surrounded by a yellow zone. Pycnidia were globose and 122 to 127 μm (average 123.5 μm) in diameter. A fungus was consistently isolated from symptomatic tissues on potato dextrose agar (PDA). Ash-black pycnidia appeared on PDA after 10 days. Ascospores developed on modified PDA (1 liter of PDA + 20 g of Duying leaves) after 18 days. Conidiogenous cells were cylindrical to obpyriform. The hyaline conidia were obovoid and guttulate, 10 to 13 × 6 to 8 μm (average 11.5 × 7.5 μm), and usually surrounded by a mucilaginous sheath with a hyaline apical appendage that was 5 to 8 μm long. Pseudothecia were solitary and subglobose with long necks. Asci were 45 to 70 × 7.5 to 12 μm (average 62.5 × 10.8 μm). Ascospores were 12 to 13 × 4 to 5 μm with rounded apices and hyaline, mucilaginous, apical caps. The fungus was morphologically identified as Phyllosticta anacardiacearum van der Aa (teleomorph Guignardia mangiferae A. J. Roy). This identification was also confirmed by the China General Microbiological Culture Collection Center (CGMCC). Six representative fungal isolates were identified by sequencing the internal transcribed spacer (ITS) region of the rDNA and comparing the sequences with those in GenBank using BLAST searches. The ITS sequences of six cultures (GenBank Accession Nos. EU821356–EU821361) showed 100% identity with the ITS sequences of an isolate of a Phyllosticta sp. (GenBank Accession No. AF532314) (2) and G. mangiferae (GenBank Accession No. AY277717) (1). To fulfill Koch's postulates, a conidial suspension (106 conidia per ml) collected from PDA cultures (isolate phy01) was used to spray inoculate leaves of potted 3-year-old Duying trees. Inoculated trees were kept for 48 h under a polyethylene sheet cover and grown at 10 to 15°C in a greenhouse. A total of 30 leaves of five healthy trees were inoculated with the pathogen. In addition, five 3-year-old trees were sprayed with sterile water to serve as uninoculated controls. After 10 to 14 days, inoculated leaves showed infection symptoms resembling those observed on Duying trees naturally infected with P. anacardiacearum. The pathogen was reisolated from the margins of necrotic tissues, but not from controls. To our knowledge, this is the first report of leaf blight on E. glabripetalus caused by P. anacardiacearum in China. Reference: (1) F. R. Katia et al. Mycol. Res. 108:45, 2004. (2) A. K. Pandey et al. Mycol. Res. 107:439, 2003.
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Shi, Qianqian, Long Li, Lin Zhou und Yan Wang. „Morphological and Biochemical Studies of the Yellow and Purple–red Petal Pigmentation in Paeonia delavayi“. HortScience 53, Nr. 8 (August 2018): 1102–8. http://dx.doi.org/10.21273/hortsci13118-18.
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Paeonia delavayi is a species endemic to Southwest China and an important genetic resource for flower color breeding of tree peonies. The mechanisms underlying the flower coloration of this plant have not been fully elucidated. In this article, the petals of yellow-colored individual (Pl) and purple–red-colored individual (Pd) of P. delavayi were studied. And anatomical observations revealed that a large amount of yellow protoplasts and a small amount of colorless protoplasts were located in the yellow-colored Pl petals, whereas a mixture of purple, red, and pink protoplasts were observed in the purple–red-colored Pd petals. The Pl cells were subrotund and flat, whereas the Pd cells were irregularly polygon-shaped and bulging. Chemical analyses were performed, and the results indicated that significant differences occurred between the cell sap pH of the Pl and Pd flowers and large differences occurred in the contents of Fe and Al between Pl and Pd. Cyanidin- and peonidin-based anthocyanins with flavones and flavonols as copigments determined the Pd flower color, whereas chalcone 2 ′G with apigenin 7-O-neohesperidoside and chrysoeriol 7-O-glucoside as copigments determined the yellow color of Pl. Correspondingly, the genes dihydroflavonol 4-reductase (DFR) and anthocyanidin synthase (ANS) were significantly highly expressed in Pd, whereas chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), flavone synthase (FNS), flavonol synthase (FLS), flavonoid 7-O-glycosyltransferase (7GT), and 2′4′6′4-tetrahydroxychalcone 2′-glucosyltransferase (THC) had high transcript levels in Pl relative to Pd. The results indicate that the color variation of P. delavayi petals may be related to a delicately controlled balance of the aforementioned factors.
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Li, Z. N., H. Min, Y. Yan, Z. Zhao, W. J. Wu und Y. F. Wu. „First Report of Syringa oblata and S. reticulata Leafroll Disease in China“. Plant Disease 93, Nr. 3 (März 2009): 322. http://dx.doi.org/10.1094/pdis-93-3-0322c.
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Syringa oblata is an important ornamental tree widely grown in China. In September of 2008, S. oblata plants exhibiting symptoms of leafroll and yellowing were found in a garden on the Northwest A&F University campus. Samples were collected from this site. Total DNA was extracted from 0.5 g of phloem tissue from leaf midribs and stems of each sample. DNA samples were analyzed with a nested PCR assay using phytoplasma 16S rDNA universal primers R16mF2/R16mR1 followed by specific primers R16F2n/R16R2 (1), which amplified a 1,452- and 1,246-bp product, respectively. We tested all 30 lilac samples, 20 of which had symptoms of leafroll and yellowing. These produced the expected 1,452- and 1,246-bp PCR products In contrast, the remaining 10 samples from symptomless trees yielded no PCR products. We also surveyed another lilac variety (Syringa reticulata), which is widely grown on the campus, and tested 50 samples with the above method. Again, 1.4- and 1.2-kb PCR products were amplified from all 30 trees displaying leafroll and yellowing symptoms, but not from the other 20 samples from symptomless trees. A comparative analysis of sequences derived from the two hosts showed that the phytoplasmas infecting them were most similar (>99%) to paulownia witches'-broom (PaWB) phytoplasma (GenBank Accession No. EF199937). Restriction fragment length polymorphism (RFLP) analysis of the nested 1.2-kb 16S rDNA products with endonucleases AluI and MseI indicated that all symptomatic plants were infected by the phytoplasmas belonging to aster yellow group (16SrI) subgroup D (16SrI-D) PaWB phytoplasma (2). 16S rDNA sequence comparisons and RFLP analysis of the cloned 16S rDNA from S. oblata (GenBank Accession No. FJ445224) and S. reticulate (GenBank Accession No. FJ445225) indicated that the phytoplasmas infecting them were nearly identical (99.8% identity). To our knowledge, this is the first report of the presence of the phytoplasma associated with a leafroll disease of S. oblata and S. reticulata in China. References: (1) D. E. Gundersen and I.-M. Lee. Phytopathol. Mediterr. 35:144, 1996. (2) I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998.
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PALEE, P., J. DENDUANGBORIPANT, V. ANUSARNSUNTHORN und M. MÖLLER. „MOLECULAR PHYLOGENY AND CHARACTER EVOLUTION OF DIDYMOCARPUS (GESNERIACEAE) IN THAILAND“. Edinburgh Journal of Botany 63, Nr. 2-3 (Juli 2006): 231–51. http://dx.doi.org/10.1017/s0960428606000540.
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Until recently the genus Didymocarpus Wall. (Gesneriaceae) was used in an unwarrantably wide sense and included more than 180 species. It has now been remodelled and restricted to around 70 species. Of these, 18 species and one variety are known to occur in Thailand. To clarify the relationships among Thai species of Didymocarpus we sequenced the internal transcribed spacers (ITS) of nuclear ribosomal DNA (nrDNA) from a sample of 23 taxa, including 15 from Thailand, four from China, three from Malaysia and one from Bhutan. Seventeen morphological characters were coded for all 23 taxa and optimized onto a retention index (RI) reweighted maximum parsimony (MP) tree. The phylogenetic analyses suggested that Didymocarpus taxa formed a strongly supported monophyletic clade, with several supported subclades. The combination of molecular phylogeny and optimization of morphological characters suggests the presence of three distinct groups: the first, corresponding to Didymocarpus sect. Elati Ridl., includes plants with tall stems, yellow or white flowers and one-celled conoid or two-celled headed pigment glands; the other two groups, which represent Didymocarpus sect. Didymocarpus, both contain plants with dwarfed stems and violet or purple flowers, but are distinguished by the presence of both four-celled conoid or onecelled globose glands in one, and the absence in the other. Optimization of geographical locality onto the phylogeny led us to propose the hypothesis that, based on this sample, the geographical origin of Didymocarpus is the Malay Peninsula, and the ancestral corolla colour is white/yellow. Subsequent dispersal northward through southern and northern Thailand to China and Bhutan was accompanied by the evolution of a purple/violet corolla colour.
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Jiao, Leilei, Weiwei Sun, Gang Yang, Guangbo Ren und Yinnian Liu. „A Hierarchical Classification Framework of Satellite Multispectral/Hyperspectral Images for Mapping Coastal Wetlands“. Remote Sensing 11, Nr. 19 (26.09.2019): 2238. http://dx.doi.org/10.3390/rs11192238.
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Mapping different land cover types with satellite remote sensing data is significant for restoring and protecting natural resources and ecological services in coastal wetlands. In this paper, we propose a hierarchical classification framework (HCF) that implements two levels of classification scheme to identify different land cover types of coastal wetlands. The first level utilizes the designed decision tree to roughly group land covers into four rough classes and the second level combines multiple features (i.e., spectral feature, texture feature and geometric feature) of each class to distinguish different subtypes of land covers in each rough class. Two groups of classification experiments on Landsat and Sentinel multispectral data and China Gaofen (GF)-5 hyperspectral data are carried out in order to testify the classification behaviors of two famous coastal wetlands of China, that is, Yellow River Estuary and Yancheng coastal wetland. Experimental results on Landsat data show that the proposed HCF performs better than support vector machine and random forest in classifying land covers of coastal wetlands. Moreover, HCF is suitable for both multispectral data and hyperspectral data and the GF-5 data is superior to Landsat-8 and Sentinel-2 multispectral data in obtaining fine classification results of coastal wetlands.
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Li, Kailong, Guohe Huang und Brian Baetz. „Development of a Wilks feature importance method with improved variable rankings for supporting hydrological inference and modelling“. Hydrology and Earth System Sciences 25, Nr. 9 (09.09.2021): 4947–66. http://dx.doi.org/10.5194/hess-25-4947-2021.
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Abstract. Feature importance has been a popular approach for machine learning models to investigate the relative significance of model predictors. In this study, we developed a Wilks feature importance (WFI) method for hydrological inference. Compared with conventional feature importance methods such as permutation feature importance (PFI) and mean decrease impurity (MDI), the proposed WFI aims to provide more reliable variable rankings for hydrological inference. To achieve this, WFI measures the importance scores based on Wilks Λ (a test statistic that can be used to distinguish the differences between two or more groups of variables) throughout an inference tree. Compared with PFI and MDI methods, WFI does not rely on any performance measures to evaluate variable rankings, which can thus result in less biased criteria selection during the tree deduction process. The proposed WFI was tested by simulating monthly streamflows for 673 basins in the United States and applied to three interconnected irrigated watersheds located in the Yellow River basin, China, through concrete simulations for their daily streamflows. Our results indicated that the WFI could generate stable variable rankings in response to the reduction of irrelevant predictors. In addition, the WFI-selected predictors helped random forest (RF) achieve its optimum predictive accuracy, which indicates that the proposed WFI could identify more informative predictors than other feature importance measures.
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Zhou, Yu, Lin Zhang, Xiaoming Zhang, Hongyue Zu, Hong Di, Ling Dong, Xianjun Liu et al. „Rice black-streaked dwarf virus Genome in China: Diversification, Phylogeny, and Selection“. Plant Disease 101, Nr. 9 (September 2017): 1588–96. http://dx.doi.org/10.1094/pdis-12-16-1814-re.
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Rice black-streaked dwarf virus (RBSDV), a Fijivirus, causes maize rough dwarf disease and rice black-streaked dwarf disease in the summer maize-growing regions of the Yellow and Huai rivers, respectively, in China. Nevertheless, the diversification and selection of the entire genome from S1 to S10 have not been illuminated. Molecular variation, evolution, conserved regions, and other genomic properties were analyzed in 21 RBSDV isolates from maize (Zea mays L.) and rice (Oryza sativa) hosts sampled from nine geographic locations in China. Low codon adaptation index values ranging from 0.1878 to 0.2918 indicated a low degree of codon-usage bias and low potential expression for all 13 RBSDV open reading frames (ORFs). ORF9-2 showed a stronger effect of codon usage bias than did other ORFs, as the majority of points for this ORF lay close to the standard curve in the Nc plot (the effective number of codons [Nc] versus the frequency of G+C at synonymous third-base positions [GC3]). A 9-bp deletion mutation was detected in the RBSDV genome in the 3′ UTR of S8. Nucleotide diversity analysis indicated that the structural proteins of RBSDV, such as S2 and S4, were all more conserved than nonstructural proteins such as S9. Nucleotide diversity (π) was highest among S9 sequences (0.0656), and was significantly higher than among S4 sequences (0.0225, P < 0.01). The number of conserved regions among the 10 segments varied substantially. The highest number of conserved regions (5) was found in S5, whereas no conserved regions were identified in S9. Nucleotide diversity and the number of conserved regions were independent of the lengths of segments. Nucleotide diversity was also not correlated with the number of conserved regions in segments. Ten recombination events in 21 isolates were found in seven segments with breakpoint positions in UTRs, intergenic spacer regions, and gene coding regions. The number of recombination events was also independent of the lengths of segments. RBSDV isolates from China could be phylogenetically classified into two groups using either 10 segment sequences or the concatenated sequence of S1 through S10, regardless of host or geographical location. The phylogenetic tree generated from pairwise nucleotide identities of individual RBSDV segments such as S9 and S3, with nucleotide identity values of 93.74% and 95.86%, respectively, is similar to the tree constructed from the concatenated sequences of the entire RBSDV genome. The 13 RBSDV ORFs were under negative and purifying selection (Ka/Ks < 1). ORF5-2 was under the greatest selection pressure; however, ORF2, which encodes the core protein of RBSDV, was under the lowest selection pressure.
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Yang, Y. A., H. Q. Wang, R. Guo, Z. M. Cheng, S. F. Li und T. Sano. „First Report of Hop stunt viroid in Apricot in China“. Plant Disease 90, Nr. 6 (Juni 2006): 828. http://dx.doi.org/10.1094/pd-90-0828c.
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Hop stunt viroid (HSVd), a member of the family Pospiviroidae, was first described as the causal agent of hop stunt disease in Japan. It has since been found in a wide range of hosts including herbaceous and woody hosts (e.g., hop, cucumber, grapevine, citrus, plum, peach, pear, apricot, almond, and pomegranate). It was also detected and characterized in apricot where infection appears to be latent (1). The viroid occurs frequently in apricot. In southeastern Spain, the presence of HSVd was found to infect 81% of apricot trees (2). Apricots originated in China and are extensively cultivated, but HSVd infection in this host has not been reported. In September 2005, a single symptomatic apricot tree, ‘Yin Bai’, one of the most popular and widely grown cultivars in China, was discovered at the Institute of Fruit Science in Changping District in Beijing, Peoples Republic of China. Observed symptoms included a number of yellow spots with an irregular border that scattered in an irregular manner over the leaf surface. Total RNA was extracted and used for return-polyacrylamide gel electrophoresis and reverse transcription-polymerase chain reaction (RT-PCR) (4). Results of both assays were positive for HSVd. A 297-bp full-length DNA fragment was amplified by RT-PCR using primers R1 (5′-GCTGGATTCTGAGAAGAGTT-3′) complementary to HSVd residues 87–106 for the RT reaction, followed by R2 (5′-AACCCGGGGCTCCTTTCTCA-3′) complementary to HSVd residues 67–84 and forward primer F3 (5′-AACCCGGGGCAACTCTTCTC-3′) residues 79–96 for PCR. The primers are located in the strictly conserved central region of the conserved HSVd group and contain the unique endonuclease restriction site SmaI. The amplified products were cloned into pGEM-T (Promega, Madison, WI) and selected for further analysis on the basis of the results of restriction digests. Six individual clones were sequenced and three different sequences were obtained. Nucleic acid sequence (GenBank Accession No. DQ362901) obtained from one clone was 99.3% (nucleotide changes T206→C, C233→T) identical to HSVd.apr8 (GenBank Accession No. Y09349) (3). Sequence (GenBank Accession No. DQ362904) obtained from three clones was 99.7% (nucleotide change C233→T) and a third sequence (GenBank Accession No. DQ362905) obtained from two clones was 99.3% (nucleotide changes G107→A, C233→T) identical to HSVd.apr8. Further investigation is necessary to determine whether the symptoms observed are associated with the viroid infection. To our knowledge, this is the first report of HSVd isolated from apricot in China. References: (1) N. Astruc et al. Eur. J. Plant Pathol. 102:837, 1996. (2) M. C. Cañzres et al. Acta Hortic. 472:581, 1998. (3) S. A. Kofalvi et al. J. Gen. Virol. 78:3177, 1997. (4) S. F. Li et al. Ann. Phytopathol. Soc. Jpn. 61:381, 1995.
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Xu, B., X. H. Zheng, W. X. Guo, X. P. Zhou und P. He. „First Report of Pomegranate Wilt Caused by Ceratocystis fimbriata in Sichuan Province“. Plant Disease 95, Nr. 6 (Juni 2011): 776. http://dx.doi.org/10.1094/pdis-02-11-0146.
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During May of 2009, a new devastating disease was observed on pomegranate (Punica granatum L.) that caused losses estimated at 30% as surveyed by 10 orchards in Panzhihua-Xichang Region of Sichuan Province, Southwest China. Characteristic symptoms were yellow and wilting leaves. Initial symptoms only occurred on shoots, but later, leaves of the whole tree turned yellow and wilted, causing extensive defoliation and dieback and the xylem of the trunk turned brown to black with a star burst-like pattern. Finally, heavy infection resulted in the whole tree dying, causing severe yield losses. A fungus was consistently isolated from basal stems and roots of diseased plants. Single conidia were obtained and cultured on potato dextrose agar (PDA) and incubated at 25 ± 1°C with a 12-h light/dark photoperiod. Mycelium was initially hyaline and then rapidly became dark greenish brown. Two types of endoconidia were produced in 5 days. Barrel-shaped conidia were hyaline, 1-celled, and measured 7.3 to 9.4 × 11.6 to 13.2 μm. Cylindrical conidia were hyaline, 1-celled, and measured 9.2 to 29.6 × 3.1 to 6.8 μm. Aleurioconidia were brownish, thick walled, near globose, and measured 8.7 to 18.1 × 8.2 to 10.7 μm. Perithecia were dark brown to black, globose, measured 90.8 to 149.8 μm in diameter, and had a long thin neck, 254.4 to 533.8 μm long, through which ascospores exuded. Ascospores were small, hyaline, hat shaped, measured 3.7 to 6.5 × 3.1 to 5.7 μm, and accumulated in a sticky matrix at the tip of the ascomal neck. The fungus was identified as Ceratocystis fimbriata (anamorph Chalara sp.) (1). The internal transcribed spacer (ITS) region of rDNA was amplified with universal primers ITS4/ITS5 and sequenced (GenBank Accession No. HQ529711), and comparisons with GenBank showed 99% similarity with C. fimbriata on Colocasia esculenta from Brazil (Accession No. AM712448.1). Pathogenicity tests were conducted. Two-week-old seedlings of pomegranate cv. Qingpiruanzi, germinated in plastic containers in the greenhouse, were wounded with a needle to a depth of 0.5 mm at the base of the stem below the soil level and near the root system, and then inoculated by drenching the wounds with a spore suspension (105 conidia per ml). Control plants were inoculated with sterile water. There were four replicates for each treatment. The treated plants were incubated at 25 ± 1°C with 80 to 95% relative humidity under a 12-h light/dark photoperiod in a greenhouse. All inoculated plants wilted within 25 days after inoculation and C. fimbriata was reisolated. All control plants remained healthily. To our knowledge, this is the first finding of pomegranate wilt caused by C. fimbriata in Sichuan Province. This pathogen may pose a serious threat to pomegranate production in Sichuan where it is a major fruit tree. This pathogen has been previously reported in India (3) and Yunnan Province, China (2), but is not known elsewhere. References: (1) C. J. B. Engelbrecht and T. C. Harrington. Mycologia 97:57, 2005. (2) Q. Huang et al. Plant Dis. 87:1150, 2003. (3) Y. M. Somasekhara. Plant Dis. 83:400, 1999.
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Xu, Lian, Hai-Tao Wang, Jin-Xin Zhang, Hui Zhang, Shuai Wang und Ji-Quan Sun. „Flavobacterium alkalisoli sp. nov., isolated from rhizosphere soil of Suaeda salsa“. International Journal of Systematic and Evolutionary Microbiology 70, Nr. 6 (01.06.2020): 3888–98. http://dx.doi.org/10.1099/ijsem.0.004255.
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A Gram-negative, strictly aerobic, gliding motility, none-spore forming, yellow, rods bacterial strain, designated XS-5T, was isolated from rhizosphere soil of Suaeda salsa, in Tumd Right Banner, Inner Mongolia, PR China. A phylogenetic tree based on the 16S rRNA gene sequences and the phylogenomic tree both showed that strain XS-5T clustered with Flavobacterium beibuense F44-8T (shared 97.2 % of 16S rRNA gene similarity) and Flavobacterium rakeshii FCS-5T (97.6 %), and shared <96.0 % of 16S rRNA gene similarities with all other type strains. Strain XS-5T contained MK-6 as the major respiratory quinone. Its major polar lipids were phosphatidylethanolamine, an unidentified aminolipid and an unidentified lipid; and the major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 0, iso-C15 : 0 3-OH, Summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c), and Summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl). The genome consisted of a 3 985 855 bp circular chromosome, with a G+C content of 37.9 mol%, predicting 3616 coding sequences genes, 45 tRNA genes and three rRNA operons. The average nucleotide identity, amino acid identity and digital DNA–DNA hybridization values of strain XS-5T to F. beibuense F44-8T and F. rakeshii FCS-5T were 79.2 and 79.2 %, 81.7 and 81.6 %, 22.3 and 22.2 %, respectively. The results of phylogenetic, physiological and biochemical tests allowed the discrimination of strain XS-5T from its phylogenetic relatives. Flavobacterium alkalisoli sp. nov. is therefore proposed with strain XS-5T (=CGMCC 1.17077T=KCTC 72459T) as the type strain.
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Wang, H., Y. Zhao, R. Pu und Z. Zhang. „MAPPING ROBINIA PSEUDOACACIA FOREST HEALTH CONDITIONS BY USING COMBINED SPECTRAL, SPATIAL AND TEXTUREAL INFORMATION EXTRACTED FROM IKONOS IMAGERY“. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B8 (14.10.2016): 1425–29. http://dx.doi.org/10.5194/isprs-archives-xli-b8-1425-2016.
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In this study grey-level co-occurrence matrix (GLCM) textures and a local statistical analysis Getis statistic (Gi), computed from IKONOS multispectral (MS) imagery acquired from the Yellow River Delta in China, along with a random forest (RF) classifier, were used to discriminate <i>Robina pseudoacacia</i> tree health levels. The different RF classification results of the three forest health conditions were created: (1) an overall accuracy (OA) of 79.5% produced using the four MS band reflectances only; (2) an OA of 97.1% created with the eight GLCM features calculated from IKONOS Band 4 with the optimal window size of 13 × 13 and direction 45°; (3) an OA of 94.0% created using the four Gi features calculated from the four IKONOS MS bands with the optimal distance value of 5 and Queen’s neighborhood rule; and (4) an OA of 96.9% created with the combined 16 spectral (four), spatial (four), and textural (eight) features. The experimental results demonstrate that (a) both textural and spatial information was more useful than spectral information in determining the Robina pseudoacacia forest health conditions; and (b) IKONOS NIR band was more powerful than visible bands in quantifying varying degree of forest crown dieback.
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Fan, Wensheng, Ning Tang, Zhihua Dong, Jiming Chen, Wen Zhang, Changrun Zhao, Yining He et al. „Genetic Analysis of Avian Coronavirus Infectious Bronchitis Virus in Yellow Chickens in Southern China over the Past Decade: Revealing the Changes of Genetic Diversity, Dominant Genotypes, and Selection Pressure“. Viruses 11, Nr. 10 (26.09.2019): 898. http://dx.doi.org/10.3390/v11100898.
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The high mutation rates of infectious bronchitis virus (IBV) pose economic threats to the poultry industry. In order to track the genetic evolutionary of IBV isolates circulating in yellow chickens, we continued to conduct the genetic analyses of the structural genes S1, E, M, and N from 64 IBV isolates in southern China during 2009–2017. The results showed that the dominant genotypes based on the four genes had changed when compared with those during 1985–2008. Based on the S1 gene phylogenetic tree, LX4-type (GI-19) was the most dominant genotype, which was different from that during 1985–2008. The second most dominant genotype was LDT3-A-type, but this genotype disappeared after 2012. New-type 1 (GVI-1) isolates showed increasing tendency and there were four aa (QKEP) located in the hypervariable region (HVR) III and one aa (S) insertion in all the New-type 1 isolates. Both the analyses of amino acid entropy and molecular evolutionary rate revealed that the variations from large to small were S1, E, M, and N. Purifying selection was detected in the S1, E, M, and N gene proteins, which was different from the positive selection during 1985–2008. Six isolates were confirmed to be recombinants, possibly generated from a vaccine virus of the 4/91-type or LDT3-A-type and a circulating virus. The estimated times for the most recent common ancestors based on the S1, E, M, and N genes were the years of 1744, 1893, 1940, and 1945, respectively. Bayesian skyline analysis revealed a sharp decrease in genetic diversity of all the four structural genes after 2010 and since late 2015, the viral population rapidly rose. In conclusion, the IBVs circulating in southern China over the past decade have experienced a remarkable change in genetic diversity, dominant genotypes, and selection pressure, indicating the importance of permanent monitoring of circulating strains and the urgency for developing new vaccines to counteract the emerging LX4-type and New-type IBVs.
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Xiao, Yi-Ping, Wei Hui, Jung-Sook Lee, Keun Chul Lee und Zhe-Xue Quan. „Flavobacterium dongtanense sp. nov., isolated from the rhizosphere of a wetland reed“. International Journal of Systematic and Evolutionary Microbiology 61, Nr. 2 (01.02.2011): 343–46. http://dx.doi.org/10.1099/ijs.0.022301-0.
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Two strains of Gram-reaction-negative, rod-shaped, non-spore-forming, non-motile, aerobic bacteria, designated LW30T and LW29, were isolated from the rhizosphere of a wetland reed in Dongtan, Chongming Island, China. The strains formed pale-yellow colonies on R2A plates. Growth occurred at 4–37 °C (optimum 30 °C), at pH 6–9 (optimum pH 7–8) and in the presence of 0–3 % (w/v) NaCl (optimum 0–1 %). Oxidase and catalase activities and flexirubin-type pigments were absent. MK-6 was the major respiratory quinone. The major fatty acids were iso-C15 : 0, C15 : 0, iso-C15 : 1 G and iso-C17 : 1 ω9c. Strains LW30T and LW29 could be differentiated from related species by several phenotypic characteristics. Phylogenetic analyses based on 16S rRNA gene sequences placed strains LW30T and LW29 in the genus Flavobacterium with high sequence similarity to Flavobacterium cheniae NJ-26T (94.0 %) and Flavobacterium indicium GPTSA 100-9T (93.9 %). Together with F. indicium GPTSA 100-9T, strains LW30T and LW29 formed a distinct group in the phylogenetic tree. The DNA G+C content was 30 mol%. On the basis of the phylogenetic and phenotypic evidence, strains LW30T and LW29 represent a novel species of the genus Flavobacterium, for which the name Flavobacterium dongtanense sp. nov. is proposed. The type strain is LW30T (=KCTC 22671T =CCTCC AB 209201T).
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Tang, Q. H., X. Q. Niu, F. Y. Yu, H. Zhu, W. W. Song und W. Q. Qin. „First Report of Pindo Palm Heart Rot Caused by Ceratocystis paradoxa in China“. Plant Disease 98, Nr. 9 (September 2014): 1282. http://dx.doi.org/10.1094/pdis-04-14-0395-pdn.
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On January 12th, 2012, a novel disease with an incidence of 50% was discovered in Pindo palm Butia capitata (Mart.) Becc from the Coconut Grant View Garden (19°33.137′ N, 110°47.482′ E) located in Wenchang, Hainan Province. Diseased leaflets at the base of the rotted heart leaves had reddish brown lesions; when the infection progressed, the leaves turned yellow and became blighted from the inner to the outer part of the crown. Once the growing point was destroyed, the entire tree ultimately died. Tissues from the edges of lesions from diseased leaflet samples were placed onto potato dextrose agar (PDA) and incubated at 25°C for 3 days. The color of colonies of five isolates obtained turned from white to black in 48 h. The optimum temperature for mycelium growth was from 20 to 30°C, and no growth occurred at temperatures higher than 40°C or lower than 5°C (n = 5). The cylindrical colorless to pale brown conidia were 7.5 to 17.5 μm long × 5.0 to 7.5 μm wide (n = 100); oval black chlamydospores were 12.5 to 22.5 × 7.5 to 15.0 μm (n = 100). The sequence (497 bp) of the internal transcribed spacer (ITS) region of the representative isolate BX3 (China Center for Type Culture Collection No. CCTCC AF2014002) was amplified using primer pair ITS1/ITS4 (GenBank Accession No. KF939052) and shared 99% sequence identity with Ceratocystis paradoxa strain xie331-4 (JQ039332). Based upon these biological characteristics and ITS sequence, this pathogen was identified as C. paradoxa (Dade) C. Moreau (anamorph Thielaviopsis paradoxa (de Seynes) Höhn.) (3). Pathogenicity tests were conducted on 8-cm-long sections of young leaflets excised from a 12-year-old pindo palm tree. One side of the midrib of 10 sections was wounded with a sterilized scalpel at the center and the other side was non-wounded, then a PDA plug (4 to 6 × 4 to 6 mm) from the edge of an actively growing colony of BX3 incubated for 3 days were inoculated onto each wounded or non-wounded site. As controls, plain PDA plugs were placed on wounded and non-wounded spots of another 10 sections following the above procedure. Pathogenicity was tested twice. Each inoculated section was then put into a 9-cm petri dish in which two filter papers (Φ = 9 cm) were placed and 8 ml of sterile water were added to maintain high humidity, and then all dishes were placed in a dark incubator at 25°C. After 5 days, typical symptoms developed only on the wounded points inoculated with mycelium plugs. C. paradoxa was re-isolated from the margins of the expanding lesions. C. paradoxa causing fruit rot of B. capitata was reported in Uruguay (2), but to our knowledge, there are no previous reports of this species in China or infecting leaves of B. capitata worldwide (1). We report here a new Ceratocystis disease on B. capitata, and it was named as pindo palm heart rot based on its symptoms. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , Feb 21, 2014. (2) V. Gepp et al. New Dis. Rep. 27:12, 2013. (3) F. Y. Yu et al. Plant Dis. 96:290, 2012.
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Wang, Yaolin, Quanlin Ma, Yingke Li, Tao Sun, Hujia Jin, Chuanyan Zhao, Eleanor Milne et al. „Energy Consumption, Carbon Emissions and Global Warming Potential of Wolfberry Production in Jingtai Oasis, Gansu Province, China“. Environmental Management 64, Nr. 6 (20.11.2019): 772–82. http://dx.doi.org/10.1007/s00267-019-01225-z.
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AbstractDuring the last decade, China's agro-food production has increased rapidly and been accompanied by the challenge of increasing greenhouse gas (GHG) emissions and other environmental pollutants from fertilizers, pesticides, and intensive energy use. Understanding the energy use and environmental impacts of crop production will help identify environmentally damaging hotspots of agro-production, allowing environmental impacts to be assessed and crop management strategies optimized. Conventional farming has been widely employed in wolfberry (Lycium barbarum) cultivation in China, which is an important cash tree crop not only for the rural economy but also from an ecological standpoint. Energy use and global warming potential (GWP) were investigated in a wolfberry production system in the Yellow River irrigated Jingtai region of Gansu. In total, 52 household farms were randomly selected to conduct the investigation using questionnaires. Total energy input and output were 321,800.73 and 166,888.80 MJ ha−1, respectively, in the production system. The highest share of energy inputs was found to be electricity consumption for lifting irrigation water, accounting for 68.52%, followed by chemical fertilizer application (11.37%). Energy use efficiency was 0.52 when considering both fruit and pruned wood. Nonrenewable energy use (88.52%) was far larger than the renewable energy input. The share of GWP of different inputs were 64.52% electricity, 27.72% nitrogen (N) fertilizer, 5.07% phosphate, 2.32% diesel, and 0.37% potassium, respectively. The highest share was related to electricity consumption for irrigation, followed by N fertilizer use. Total GWP in the wolfberry planting system was 26,018.64 kg CO2 eq ha−1 and the share of CO2, N2O, and CH4 were 99.47%, 0.48%, and negligible respectively with CO2 being dominant. Pathways for reducing energy use and GHG emission mitigation include: conversion to low carbon farming to establish a sustainable and cleaner production system with options of raising water use efficiency by adopting a seasonal gradient water pricing system and advanced irrigation techniques; reducing synthetic fertilizer use; and policy support: smallholder farmland transfer (concentration) for scale production, credit (small- and low-interest credit) and tax breaks.
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Cao, X. T., Y. B. Bian und Z. Y. Xu. „First Report of Trichoderma oblongisporum Causing Green Mold Disease on Lentinula edodes (shiitake) in China“. Plant Disease 98, Nr. 10 (Oktober 2014): 1440. http://dx.doi.org/10.1094/pdis-05-14-0537-pdn.
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Lentinula edodes (shiitake) is well known for its delicious taste and valuable medical functions, and ranked as the second most important mushroom in terms of total world production. In March 2012, a serious green mold epidemic occurred on many mushroom farms in Suizhou County of China. The infected mycelia of L. edodes in cultivated bags became rotten, yellow, wilted, and finally died, with the surfaces of the cultivated bags covered with dark green fungal colonies. At a temperature above 20°C, disease incidence was nearly 100% on some mushroom farms. Three diseased cultivated bags were collected from three different mushroom farms, and two portions at the junction of the diseased and healthy portions of the bag were plated individually on potato dextrose agar (PDA) and incubated at 25°C for 4 days. Following incubation, agar discs cut from the growing front of colonies were inoculated onto fresh PDA and subcultured to obtain putative pathogens. Three purified isolates were all whitish initially, followed by the emergence of greenish conidial clusters at the outer margin of the colony. The underside of the colony appeared pale yellow. The growth rate of the isolates was about 0.95 to 1.02 cm/day in PDA at 25°C. Aerial mycelia were floccose, white, and septate. Chlamydospores were sub-globose to broadly ellipsoidal. Conidiophore branches arose at right angles, and primary branches arose singly or in pairs. Phialides were ampulliform, 3.1 to 6.7 × 2.7 to 4.0 μm, slightly constricted at the base, swollen in the middle, and narrowed abruptly at the apex. Conidia were produced on the top of the phialides with the shape varying from ellipsoidal to oblong, 3.3 to 4.7 × 2.4 to 3.2 μm. These observations were consistent with the description of Trichoderma oblongisporum by Bissett (1). The ITS and partial tef1 were amplified from the three isolates as previously reported (2) and sequenced (KM110064 to KM110069). Nucleotide alignment showed 99% sequence identity (ITS) with two T. oblongisporum isolates (FJ623268 and DQ083020), and 88% similarity (tef1) with T. oblongisporum (AY750884). Neighbor joining tree of ITS and tef1 nucleotide sequences also showed that our three isolates had the closest relationship with the aforementioned three T. oblongisporum strains. To determine pathogenicity, a sawdust substrate was sterilized for 2 h in polyethylene bags and subsequently inoculated separately with three isolates and L. edodes strain Qiu7, which was cultivated widely in Suizhou. When the mycelia of Qiu7 colonized the bags, 10 cm3 of substrate was withdrawn from each bag. The substrate was then exposed to 10 cm3 of mycelium from each pathogen in 10 bags. A parallel inoculation with 10 cm3 of sterilized sawdust substrate without pathogen mycelia was performed as a control. The inoculated cultivated bags were kept at 25°C. After 2 months, all of the mycelia in the bags became wilted and dead, and the cultivated bags became soft, rotten, and covered with dark green fungal colonies. The controls remained uninfected. The symptoms were similar to those observed on mushroom farms. Pathogens re-isolated from all the inoculated culture bags were confirmed to be T. oblongisporum through morphological characteristics, molecular identification, and phylogenetic analysis. To our knowledge, this is the first report of T. oblongisporum causing green mold disease on L. edodes in the world. References: (1) J. Bissett. Can. J. Bot. 69:2398, 1991. (2) N. Sadfi-Zouaoui et al. Can. J. Microbiol. 55:154, 2009.
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Zhuang, Lingping, Binbin Lin und Lianzhong Luo. „Mangrovimonas spongiae sp. nov., a novel member of the genus Mangrovimonas isolated from marine sponge“. International Journal of Systematic and Evolutionary Microbiology 70, Nr. 3 (01.03.2020): 1982–86. http://dx.doi.org/10.1099/ijsem.0.004006.
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A taxonomic study was carried out on strain HN-E26T, which was isolated from sponge collected from Yangpu Bay, Hainan, PR China. Cells of strain HN-E26T were Gram-stain-negative, motile by gliding, yellow-pigmented and rod-shaped. The strain could grow at 10–40 °C (optimum, 25 °C), at pH 6.0–9.0 (optimum, pH 7.0) and in 0.5–12 % (w/v) NaCl (optimum, 4–7 %). This isolate was positive for oxidase, catalase, and the hydrolysis of starch, xylan, aesculin and gelatin, but negative for indole production and the reduction of nitrate. Strain HN-E26T shared the highest 16S rRNA gene sequence similarity with Mangrovimonas yunxiaonensis LYYY01T (95.5 %), followed by Formosa spongicola A2T (94.4 %), Meridianimaribacter flavus NH57NT (94.3 %) and Winogradskyella exilis 022-2-26T (94.3 %). The phylogenetic tree based on 16S rRNA gene sequences revealed that strain HN-E26T formed a distinct phylogenetic lineage within the cluster comprising Mangrovimonas yunxiaonensis LYYY01T and ‘ Mangrovimonas xylaniphaga ’ ST2L12T. The dominant fatty acids were iso-C15 : 0 and iso-C15 : 1 G. The major polar lipids comprised phosphatidylethanolamine, three unidentified aminolipids and six unidentified lipids. The respiratory lipoquinone was identified as MK-6. The G+C content of the genomic DNA was 33.9 mol%. Based on the phenotypic and phylogenetic data, strain HN-E26T represents a novel species of the genus Mangrovimonas , for which the name Mangrovimonas spongiae sp. nov. is proposed, with the type strain HN-E26T (=MCCC 1K03326T=LMG 30458T).
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Feng, Xi, Yi-Ran Wang, Qi-Hang Zou, Jin-Yu Zhang und Zong-Jun Du. „Haloflavibacter putidus gen. nov., sp. nov., isolated from coastal seawater“. International Journal of Systematic and Evolutionary Microbiology 70, Nr. 6 (01.06.2020): 3740–48. http://dx.doi.org/10.1099/ijsem.0.004228.
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A Gram-stain-negative, aerobic, gliding, rod-shaped (0.2–0.5×1.0-13.0 µm) and yellow-pigmented bacterium, designated PLHSN227T, was isolated from seawater collected near the coast of Yantai, PR China. PLHSN227T was found to grow at 15–37 °C (optimum, 28–30 °C) and pH 6.0–8.5 (optimum, 6.5–7.5) in the presence of 2–14 % (w/v) NaCl (optimum, 5.0 %). Phylogenetic analysis of the 16S rRNA gene sequences revealed that PLHSN227T represented a member of the family Flavobacteriaceae and exhibited the highest sequence similarity (94.6 %) to the type strain Salegentibacter holothuriorum NBRC 100249T. The chemotaxonomic analysis revealed that the sole respiratory quinone was menaquinone 6 (MK-6) and the major fatty acids included C19 : 0ω8c cyclo, iso-C15 : 0, anteiso-C15 : 0, C18 : 0 and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The major polar lipids included phosphatidylethanolamine, one unidentified aminolipid and two unidentified lipids. The DNA G+C content of PLHSN227T was 35.6 mol%. PLHSN227T showed the highest average amino acid identity value of 67.2 %, the average nucleotide identity value of 75.6 and 14.5 % digital DNA–DNA hybridization identity with Mesonia algae DSM 15361T. According to the phylogenetic data, PLHSN227T formed a distinct clade in the phylogenetic tree. On the basis of phenotypic, chemotaxonomic and phylogenetic data, it is considered that PLHSN227T represents a novel genus within the family Flavobacteriaceae , for which the name Haloflavibacter putidus gen. nov., sp. nov. is proposed. The type strain is PLHSN227T (=KCTC 72159T=MCCC 1H00371T).
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Lee, S. H., C. K. Lee, M. J. Park und H. D. Shin. „First Report of Leaf Spot Caused by Ascochyta marginata on Aralia elata in Korea“. Plant Disease 96, Nr. 1 (Januar 2012): 147. http://dx.doi.org/10.1094/pdis-08-11-0658.
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Aralia elata (Miq.) Seem., known as Japanese angelica tree, is a deciduous shrub belonging to the Araliaceae, which is native to East Asia. The young shoots have long been used in various dishes in East Asia. Commercial cultivation of this shrub, especially in polytunnels, is expanding in Korea. Several diseases including Sclerotinia rot have been known to be present on this plant (1,2). In early September 2007, leaf spot symptoms were first observed on several trees in Hongcheon, Korea. Microscopic observations revealed that the leaf spots were associated with an Ascochyta sp. Further surveys of the Ascochyta leaf spot showed the occurrence of the disease in approximately 5 to 10% of the trees in the 3 ha of commercial fields surveyed in Chuncheon, Gapyeong, Inje, and Jinju, Korea. Initial symptoms on leaves were circular to irregular, brown to dark brown, becoming zonate, and finally fading to grayish brown in the center with a yellow halo. Representative samples were deposited in the herbarium of Korea University. Conidiomata on leaf lesions were pycnidial, amphigenous, but mostly epiphyllous, immersed or semi-immersed in host tissue, light brown to olive brown, and 60 to 200 μm in diameter. Ostioles were papillate, 20 to 35 μm wide, and surrounded by a ring of darker cells. Conidia were hyaline, smooth, cylindrical to clavate, straight to mildly curved, slightly constricted at the septa, medianly one-septate, sometimes aseptate, 8 to 16 × 2.5 to 3.5 μm, and contained small oil drops. These morphological characteristics were consistent with the previous reports of Ascochyta marginata J.J. Davis (3,4). A monoconidial isolate was cultured on potato dextrose agar (PDA) plates and accessioned in the Korea Agricultural Culture Collection (Accession KACC43082). The conidia were readily formed on PDA. Inoculum for the pathogenicity tests was prepared by harvesting conidia from 30-day-old cultures of KACC43082 and a conidial suspension (approximately 2 × 106 conidia/ml) was sprayed onto leaves of three healthy seedlings. Three noninoculated seedlings served as controls. Inoculated and noninoculated plants were covered with plastic bags for 48 h in a glasshouse. After 7 days, typical leaf spot symptoms started to develop on the leaves of the inoculated plants. The fungus, A. marginata, was reisolated from those lesions, confirming Koch's postulates. No symptoms were observed on control plants. Previously, the disease was reported in Japan (4) and China (3). To our knowledge, this is the first report of A. marginata on Japanese angelica trees in Korea. According to our field observations in Korea, the Ascochyta leaf spot mostly occurred on plants growing in a humid environment, especially during the rainy season. The seedlings as well as the trees growing in sunny, well-ventilated plots were nearly free from this disease. Therefore, the growing conditions seemed to be the most important factor for the development and severity of the disease. References: (1) C. K. Lee et al. Plant Pathol. J. 26:426, 2010. (2) S. H. Lee et al. Diseases of Japanese Angelica Tree and Their Control. Research Report 08-10. Korea Forest Research Institute. Seoul, Korea, 2008. (3) J. Sun et al. Acta Mycol. Sin. 14:107, 1995. (4) M. Yoshikawa and T. Yokoyama. Mycoscience 36:67, 1995.
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Zhao, Y. Z., D. Wang und Z. H. Liu. „First Report of Brown Rot on Crataegus pinnatifida var. major Caused by Monilia yunnanensis in China“. Plant Disease 97, Nr. 9 (September 2013): 1249. http://dx.doi.org/10.1094/pdis-01-13-0085-pdn.
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Crataegus pinnatifida Bge. var. major N. is a time-honored herbal medicine and an important economic fruit that is processed into various foods. Cultivated fields are mostly situated in northern China. In August 2012, a fruit brown rot disease on mature plants was found in Fushun, Liaoning Province, China. This disease reduced the yield and the quality of fruits; the incidence of fruits affected in each tree was between 20% and 35%. The initial stage of infection was marked by regular or irregular light brown spots turning dark brown and gradually supporting many grey fluffy tufts of mycelium. At last, the lesions expanded, causing the fruits to become rotted or withered. The pathogen was isolated from infected fruits by a tissue isolation method (1) and cultured on potato dextrose agar (PDA) at 25°C under 12 h light/12 h dark for 7 days. The colonies reached 60 to 75 mm in diameter after 7 days and were pale green or pale yellow with a neat greyish white margin; the aerial mycelium sometimes formed annulations. The conidia were single, hyaline, lemon-shaped or oval, and 11.3 ± 1.4 (8.0 to 16.5) × 6.4 ± 0.8 (5.1 to 7.6) μm; sporulation was sparse and stromata that formed after 15 days were abundant, black, and spherical to elliptical in shape. Conidiophores were simple or branched, bearing a single conidium on the tip. The internal transcribed spacer (ITS) region of rDNA amplified with primers ITS1 and ITS4 was directly sequenced in both directions. The ITS1-5.8S-ITS2 sequence of rDNA was 100% identical to Monilinia yunnanensis (GenBank Accession No. HQ908788.1), which is distinguished from the closely related M. fructigena (AF150679.1) and M. polystroma (JX315717.1). The pathogen was identified as M. yunnanensis on the basis of morphological characteristics (2) and the ITS sequence of rDNA (2,3). Pathogenicity tests were performed on detached healthy fruits. Four fruits were wounded with a sterilized nail and inoculated by placing a PDA plug of mycelia on upper surfaces of the fruits. Another four fruits treated with sterile PDA plugs served as a control. Fruits were cultured in petri dishes with a 12-h photoperiod at 25°C and 90% relative humidity. The initial symptoms on inoculated fruits were observed after 5 days, while no symptoms showed on the controls. The pathogen was reisolated from the inoculated fruit and identified as M. yunnanensis by the above methods. While M. yunnanensis has been reported to cause brown rot on peach (2), to our knowledge, this is the first report of M. yunnanensis infecting C. pinnatifida Bge. var. major N. in China. References: (1) Z. D. Fang. Research Methods of Plant Disease, 1998. (2) M. J. Hu et al. Monilinia species causing brown rot of peach in China. PLoS ONE. Online publication. doi:10.1371/journal.pone.0024990, 2011. (3) G. C. M. van Leeuwen et al. Mycol. Res. 106:444, 2002.
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Niu, X. Q., F. Y. Yu, H. Zhu und W. Q. Qin. „First Report of Leaf Spot Disease in Coconut Seedling Caused by Bipolaris setariae in China“. Plant Disease 98, Nr. 12 (Dezember 2014): 1742. http://dx.doi.org/10.1094/pdis-05-14-0522-pdn.
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Coconut (Cocos nucifera L.), an important oilseed as well as a multipurpose perennial plantation crop, is distributed and planted in humid tropical areas. In October 2012, a new leaf spot disease was observed on 3-year-old coconut seedlings in Wenchang, Hainan Province, China. The symptom first appeared as spindly or elliptical and brown flecks with water-soaked lesions that became yellow with the progress of the disease. In the later stage of the disease, the lesions merged together, gradually expanding to the leaf apex. In recent years, the disease has been prevalent in all the nursery gardens surveyed. Once young leaves got infected and nearly all the leaves of the tree showed diseased symptoms, the coconut eventually became defoliated. The pathogen was isolated from the lesion margin, surface sterilized with 75% ethanol and 0.1% mercury bichloride, washed by sterile distilled water, and then placed excising pieces of leaves from the leision margin onto potato dextrose agar (PDA). Plates were incubated at 25°C for 4 days. After 7 days, the colony was grayish black and produced black pigment in the medium. Aerial mycelium was fluffy, septate, and branched, the conidiophores were slightly flexuous or straight, 5 to 11 μm thick, and produced curved, spindle-shaped, or fusiform, septate conidia with 4 to 10 septa, measuring 39 to 86 × 9 to 16 μm, with a slightly protuberant hilum, truncated. Based on the symptoms and mycelial and conidial characters above, the fungus was identified as Bipolaris setariae (1). The pathogenicity was established and repeated for six times by following Koch's postulates. Two 1-year-old coconut seedlings were washed with sterilized water and six leaves were wounded with a sterile needle and then inoculated by spraying them with a suspension of conidia of the isolate. The seedlings were kept in two incubators at 25°C for 12 days. Inoculated leaves showed typical symptoms similar to those described above. The pathogen was re-isolated from inoculated leaves. Morphological characteristics were identical to the original isolated fungus. In contrast, the control leaves did not show any symptoms. The genomic DNA of this fungus was extracted, amplification of the internal transcribed spacer (ITS) region was performed with primer ITS1 and ITS4, and the purified PCR product was sequenced (GenBank Accession No. KJ605157). BLASTn analysis revealed 99% sequence similarity with four B. setariae isolates (HE792936.1, JX462256, GU073108.1, and FJ606786.1). Morphologic characters and sequence analysis of the ITS rDNA confirmed that the pathogen was B. setariae. Bipolaris incurvata has been reported causing disease on coconut (2), but B. setariae was not previously reported on coconut. So far, this is the first report of B. setariae caused coconut seedling leaf spot disease in Hainan, China. References: (1) K. C. da Cunha et al. J. Clin. Microbiol. 50:4061, 2012. (2) A. Kamalakannan et al. New Dis. Rep. 12:18, 2005.
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Zhuang, Lingping, Binbin Lin, Li Xu, Guoqiang Li, Chang-Jer Wu und Lianzhong Luo. „Erythrobacter spongiae sp. nov., isolated from marine sponge“. International Journal of Systematic and Evolutionary Microbiology 69, Nr. 4 (01.04.2019): 1111–16. http://dx.doi.org/10.1099/ijsem.0.003278.
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A taxonomic study was carried out on strain HN-E23T, which was isolated from sponge collected from Yangpu Bay, Hainan, China. Cells of strain HN-E23T were Gram-stain-negative, non-motile, orange-yellow-pigmented, short rods, that could grow at 10–40 °C (optimum, 28 °C), at pH 5–11 (optimun, pH 7) and in 0.5–12 % (w/v) NaCl (optimum, 3 %). This isolate was positive for oxidase, catalase, and the hydrolysis of aesculin, but negative for indole production and the reduction of nitrate. The phylogenetic tree based on 16S rRNA gene sequences revealed that strain HN-E23T formed a distinct phylogenetic lineage within the cluster comprising Erythrobacter strains. Strain HN-E23T shared the highest 16S rRNA gene sequence similarity to Erythrobacter aquimixticola JSSK-14T (97.2 %), followed by Erythrobacter atlanticus s21-N3T (96.6 %), Erythrobacter luteus KA37T (96.5 %) and Erythrobacter citreus RE35F/1T (96.4 %). The digital DNA–DNA hybridization (dDDH) and the average nucleotide identity (ANI) values between strain HN-E23T and JSSK-14T were 18.8 and 74.9 %, respectively. The dDDH and ANI values are below the standard cut-off criteria for delineation of bacterial species. The dominant fatty acids were summed feature 8 (C18 : 1ω7c/ω6c), C16 : 0 and summed feature 3 (C16 : 1ω7c/ω6c). The major polar lipids comprised phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, sphingoglycolipid, an unidentified glycolipid and six unidentified lipids. The respiratory lipoquinone was identified as Q-10. The G+C content of the genomic DNA was 65.5 mol%. Based on the phenotypic and phylogenetic data, strain HN-E23T represents a novel species of the genus Erythrobacter , for which the name Erythrobacter spongiae sp. nov. is proposed, with the type strain HN-E23T (=MCCC 1K03331T=LMG 30457T).