Journal articles: 'Gymnosperms'

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Umair, Muhammad, Xiaofei Hu, Qi Cheng, Shahzad Ali, and Jian Ni. "Distribution Patterns of Gymnosperm Species along Elevations on the Qinghai–Tibet Plateau: Effects of Climatic Seasonality, Energy–Water, and Physical Tolerance Variables." Plants 12, no. 23 (December 4, 2023): 4066. http://dx.doi.org/10.3390/plants12234066.

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Climate change is one of the most prominent factors influencing the spatial distribution of plants in China, including gymnosperms. Climatic factors influence gymnosperm distribution along elevational gradients on the Qinghai–Xizang (Tibet) Plateau (QTP), and understanding how species adapt to these factors is important for identifying the impacts of global climate change. For the first time, we examined the county-level distribution of gymnosperm species on QTP using data from field surveys, published works, monographs, and internet sources. We used simulated distribution data of gymnosperms (N = 79) along the elevational gradients to investigate the overall impact of environmental variables in explaining the richness pattern of gymnosperms. Eighteen environmental variables were classified into three key variable sets (climatic seasonality, energy–water, and physical tolerance). We employed principal component analysis and generalized linear models to assess the impact of climatic variables on the gymnosperm’s richness pattern. Gymnosperm species are unevenly distributed across the plateau and decline gradually from the southeast to the northwest. The altitudinal gradients have a unimodal relationship with the richness of gymnosperms, with the maximum species richness at an elevation of 3200 m. The joint effects of physical tolerance and energy–water predictors have explained the highest diversity of gymnosperms at mid-elevation. Because the richness peak correlates significantly with the wettest month’s precipitation and moisture index, this confirms the significance of moisture on gymnosperm distributions due to increased precipitation during the wet season. Furthermore, our results provide evidence that climatic seasonality factors are involved in the decline of gymnosperm richness at high elevations. A total of 37% of gymnosperm species on QTP are listed as vulnerable, nearly threatened, or endangered, with elevations ranging from 600 m to 5300 m. As a result, we conclude that gymnosperms are at high risk of extinction because of the current climate fluctuations caused by global climate change. Our research offers fundamental data for the study and protection of gymnosperm species along the steepest elevation gradients.

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Nurrahma, Aditiya, Ismanto ., and Taufikurrahman Nasution. "KEANEKARAGAMAN EPIFIT BERPEMBULUH PADA BATANG POHON INANG ANGIOSPERMAE DAN GYMNOSPERMAE DI KEBUN RAYA CIBODAS." EKOLOGIA 22, no. 2 (October 31, 2022): 75–82. http://dx.doi.org/10.33751/ekologia.v22i2.5789.

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Epiphytes are types of plants that attach and grow on other plants to obtain sunlight, water, air, and minerals for their growth. The aim of this study are knowing the diversity of vascular epiphytes on the host trunks of Angiosperms and Gymnosperms, knowing the differences in vascular epiphytic communities on the host trunks of Angiosperms and Gymnosperms and to determine factors causing vascular epiphytes communities on the host trunk is used in this research. Sampling plot is located on the host tree's trunk to facilitate the calculation of vascular epiphytes; a simple plot measuring 2 m x 0,5 m was made facing east and west. Determination of the number of tree sampling is done based on the Area Species Curve. The results of this study indicate that the vascular epiphyte diversity on trunks of Gymnospermae is higher than Angiospermae, meanwhile that Shannon Wiener diversity index of vascular epiphytes on Angiosperms and Gymnosperms host trunks being moderate category. Jaccard Similarity index was 0.44 and indicated the different of epiphytes community between Angiospermae and Gymnospermae tree host. The dominant species based on Important value index in Angiosperms are Davallia hymenophylloides (35,05%), Goniophlebium subauriculatum (20,92%), and Dendrobium mutabile (20,07) while ini Gymnosperme are Davallia hymenophylloides (41,36%), Goniophlebium subauriculatum (15,94%), and Peperomia tetraphylla (15,55%). In Angiospermae, the factors that influence the diversity of vascular epiphyte species are roughness and thickness, while in Gymnosperms the influential factors are roughness and diameter.

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Qi, Yang, Hongyan Liu, Chongyang Xu, Jingyu Dai, and Biao Han. "Dry Climate Filters Gymnosperms but Not Angiosperms through Seed Mass." Diversity 15, no. 3 (March 10, 2023): 401. http://dx.doi.org/10.3390/d15030401.

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In the context of climate change in recent years, the fate of woody plant seed has an important impact on forest regeneration. Seed mass is an important reproductive strategy of plants. There are huge differences between gymnosperms (mainly conifers) and angiosperms (flowering plants) in terms of reproduction and hydraulic strategies; however, little is known about changes in seed mass along climate aridity gradients between taxonomical groups such as gymnosperms and angiosperms, which limit our understanding on the fate of woody plants under warming-induced climate drying. We collected seed mass data from a total of 2575 woody plant individuals, including 145 species of gymnosperms and 1487 species of angiosperms, across different climatic zones in China. We mapped the distribution pattern of gymnosperm and angiosperm seed mass in China, with angiosperms being maximal near the 400 mm iso-precipitation line. Our phylogenetic analysis results show that seed mass exhibited significant phylogenic signals (p < 0.001) and was also strongly influenced by functional traits (growth type, fruit type, and dispersal mode). The results of linear regression and hierarchical partitioning analysis showed a stronger correlation between gymnosperm seed mass and environmental factors, and a higher independent aridity index effect on gymnosperm seed mass than angiosperm seed mass. The different patterns of seed mass along a climate aridity gradient between gymnosperms and angiosperms may point to different future fates for these two taxonomic groups, while the higher sensitivity of gymnosperm seed mass to environmental conditions may reduce their reproductive rate under the background of climate warming and drying.

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Joshi, Savita, S. C. Sati, and Parikshit Kumar. "Antibacterial potential and ethnomedical relevance of Kumaun Himalayan Gymnosperms." Journal of Phytopharmacology 5, no. 5 (October 17, 2016): 190–200. http://dx.doi.org/10.31254/phyto.2016.5505.

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Ethnomedicinal information is one of the powerful criteria for new drugs discoveries therefore; present investigation was carried out to evaluate the ethnomedicinal and antibacterial potential of traditional Kumaun Himalayan gymnosperms. Besides, an antibacterial value index and relative antibacterial activity of studied plants have been established. Forty four plant leaves extracts in different organic solvents (methanol, ethanol, chloroform and hexane) of 11 gymnosperms (Araucaria cunninghamii, Biota orientalis, Cedrus deodara, Cephalotaxus griffithi, Cryptomeria japonica Cupressus torulosa, Ginkgo biloba, Juniperus communis, Picea smithiana, Pinus wallichiana and Taxus baccata) occurring in Kumaun Himalaya were screened for their antimicrobial activity against five pathogenic bacteria using disc diffusion method. The antibacterial activity of studied gymnospermic plant extracts against a panel of bacteria was found effective at 1000 µg/ml. The MIC and MBC values of each extract (where ZOI ≥ 15 mm) were also determined. The methanol extract of screened gymnosperms were found the most effective against all the bacteria (54% to 81%), followed by ethanol extract (45-72%), hexane extract (18-27%), while in chloroform extract it ranged 9-27% only. The extracts of G. biloba exhibited superior Relative Antibacterial Activity (RAA, 20%), followed by A. cunninghamii and P. wallichiana (12% RAA, each). The lowest RAA value was observed for C. torulosa (1%). All data were also analyzed for determination of an Antibacterial Value Index (ABVI) for each studied species of gymnosperm. G. biloba had maximum ABVI i.e. 90 % followed by A. cunninghamii and P. wallichiana (ABVI, 55% each). C. torulosa showed the least ABVI and RAA i.e. 5% and 11%, respectively. The present work fully highlighted the utility of traditionally known 11 gymnosperms of Kumaun Himalaya for their antibacterial activities against pathogenic bacteria.

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Huang, Kai-Yuan, Sheng-Long Kan, Ting-Ting Shen, Pin Gong, Yuan-Yuan Feng, Hong Du, Yun-Peng Zhao, Tao Wan, Xiao-Quan Wang, and Jin-Hua Ran. "A Comprehensive Evolutionary Study of Chloroplast RNA Editing in Gymnosperms: A Novel Type of G-to-A RNA Editing Is Common in Gymnosperms." International Journal of Molecular Sciences 23, no. 18 (September 16, 2022): 10844. http://dx.doi.org/10.3390/ijms231810844.

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Although more than 9100 plant plastomes have been sequenced, RNA editing sites of the whole plastome have been experimentally verified in only approximately 21 species, which seriously hampers the comprehensive evolutionary study of chloroplast RNA editing. We investigated the evolutionary pattern of chloroplast RNA editing sites in 19 species from all 13 families of gymnosperms based on a combination of genomic and transcriptomic data. We found that the chloroplast C-to-U RNA editing sites of gymnosperms shared many common characteristics with those of other land plants, but also exhibited many unique characteristics. In contrast to that noted in angiosperms, the density of RNA editing sites in ndh genes was not the highest in the sampled gymnosperms, and both loss and gain events at editing sites occurred frequently during the evolution of gymnosperms. In addition, GC content and plastomic size were positively correlated with the number of chloroplast RNA editing sites in gymnosperms, suggesting that the increase in GC content could provide more materials for RNA editing and facilitate the evolution of RNA editing in land plants or vice versa. Interestingly, novel G-to-A RNA editing events were commonly found in all sampled gymnosperm species, and G-to-A RNA editing exhibits many different characteristics from C-to-U RNA editing in gymnosperms. This study revealed a comprehensive evolutionary scenario for chloroplast RNA editing sites in gymnosperms, and reported that a novel type of G-to-A RNA editing is prevalent in gymnosperms.

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Zhang, Ting-Ting, Yi-Kun Hou, Ting Yang, Shu-Ya Zhang, Ming Yue, Jianni Liu, and Zhonghu Li. "Evolutionary analysis of chloroplast tRNA of Gymnosperm revealed the novel structural variation and evolutionary aspect." PeerJ 8 (November 25, 2020): e10312. http://dx.doi.org/10.7717/peerj.10312.

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Gymnosperms such as ginkgo, conifers, cycads, and gnetophytes are vital components of land ecosystems, and they have significant economic and ecologic value, as well as important roles as forest vegetation. In this study, we investigated the structural variation and evolution of chloroplast transfer RNAs (tRNAs) in gymnosperms. Chloroplasts are important organelles in photosynthetic plants. tRNAs are key participants in translation where they act as adapter molecules between the information level of nucleic acids and functional level of proteins. The basic structures of gymnosperm chloroplast tRNAs were found to have family-specific conserved sequences. The tRNAΨ -loop was observed to contain a conforming sequence, i.e., U-U-C-N-A-N2. In gymnosperms, tRNAIle was found to encode a “CAU” anticodon, which is usually encoded by tRNAMet. Phylogenetic analysis suggested that plastid tRNAs have a common polyphyletic evolutionary pattern, i.e., rooted in abundant common ancestors. Analyses of duplication and loss events in chloroplast tRNAs showed that gymnosperm tRNAs have experienced little more gene loss than gene duplication. Transition and transversion analysis showed that the tRNAs are iso-acceptor specific and they have experienced unequal evolutionary rates. These results provide new insights into the structural variation and evolution of gymnosperm chloroplast tRNAs, which may improve our comprehensive understanding of the biological characteristics of the tRNA family.

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Lu, Y., B. Jin, L. Wang, Y. Wang, D. Wang, X. X. Jiang, and P. Chen. "Adaptation of male reproductive structures to wind pollination in gymnosperms: Cones and pollen grains." Canadian Journal of Plant Science 91, no. 5 (September 2011): 897–906. http://dx.doi.org/10.4141/cjps2011-020.

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Lu, Y., Jin, B., Wang, L., Wang, Y., Wang, D., Jiang, X.-X. and Chen, P. 2011. Adaptation of male reproductive structures to wind pollination in gymnosperms: Cones and pollen grains. Can. J. Plant Sci. 91: 897–906. Wind pollination (anemophily) in gymnosperms is thought to be an ancestral state. Previous studies considered wind pollination to be a largely random phenomenon, but recent evidence suggests that wind-pollinated species have evolved different complex reproductive adaptations for controlling and maximizing the success of wind pollination. However, compared with angiosperms, wind pollination in gymnosperms is poorly understood. We investigated the male reproductive structures of 13 representative gymnosperm species using a scanning electron microscope and digital camera, and analyzed how the morphological characteristics of male cones and pollen facilitate pollination. These characteristics showed a surprising variation between different gymnosperm species in improving pollination success. For example, the relationship between the position of the male cone and the surrounding vegetative structures is adjusted to optimize pollen release. The pollen grains have sacs and papilla and exhibit particular shapes after release from microsporangia, including boat-like, saccate, papilla-like and spheroid shapes, which facilitate pollen dispersal in the air. Taken together, our results suggest that the extensive diversity of male reproductive structures within gymnosperms represents an evolutionary response to long-term selection and results in solutions to the physical restraints of anemophily.

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Burleigh, J. Gordon, W. Brad Barbazuk, John M. Davis, Alison M. Morse, and Pamela S. Soltis. "Exploring Diversification and Genome Size Evolution in Extant Gymnosperms through Phylogenetic Synthesis." Journal of Botany 2012 (January 12, 2012): 1–6. http://dx.doi.org/10.1155/2012/292857.

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Gymnosperms, comprising cycads, Ginkgo, Gnetales, and conifers, represent one of the major groups of extant seed plants. Yet compared to angiosperms, little is known about the patterns of diversification and genome evolution in gymnosperms. We assembled a phylogenetic supermatrix containing over 4.5 million nucleotides from 739 gymnosperm taxa. Although 93.6% of the cells in the supermatrix are empty, the data reveal many strongly supported nodes that are generally consistent with previous phylogenetic analyses, including weak support for Gnetales sister to Pinaceae. A lineage through time plot suggests elevated rates of diversification within the last 100 million years, and there is evidence of shifts in diversification rates in several clades within cycads and conifers. A likelihood-based analysis of the evolution of genome size in 165 gymnosperms finds evidence for heterogeneous rates of genome size evolution due to an elevated rate in Pinus.

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Schmid, Rudolf, S. P. Bhatnagar, and Alok Moitra. "Gymnosperms." Taxon 47, no. 2 (May 1998): 531. http://dx.doi.org/10.2307/1223812.

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Veromann-Jürgenson, Linda-Liisa, Timothy J. Brodribb, Ülo Niinemets, and Tiina Tosens. "Variability in the chloroplast area lining the intercellular airspace and cell walls drives mesophyll conductance in gymnosperms." Journal of Experimental Botany 71, no. 16 (May 11, 2020): 4958–71. http://dx.doi.org/10.1093/jxb/eraa231.

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Abstract The photosynthetic efficiency of plants in different environments is controlled by stomata, hydraulics, biochemistry, and mesophyll conductance (gm). Recently, gm was demonstrated to be the key limitation of photosynthesis in gymnosperms. Values of gm across gymnosperms varied over 20-fold, but this variation was poorly explained by robust structure-bound integrated traits such as leaf dry mass per area. Understanding how the component structural traits control gm is central for identifying the determinants of variability in gm across plant functional and phylogenetic groups. Here, we investigated the structural traits responsible for gm in 65 diverse gymnosperms. Although the integrated morphological traits, shape, and anatomical characteristics varied widely across species, the distinguishing features of all gymnosperms were thick mesophyll cell walls and low chloroplast area exposed to intercellular airspace (Sc/S) compared with angiosperms. Sc/S and cell wall thickness were the fundamental traits driving variations in gm across gymnosperm species. Chloroplast thickness was the strongest limitation of gm among liquid-phase components. The variation in leaf dry mass per area was not correlated with the key ultrastructural traits determining gm. Thus, given the absence of correlating integrated easy-to-measure traits, detailed knowledge of underlying component traits controlling gm across plant taxa is necessary to understand the photosynthetic limitations across ecosystems.

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Pesacreta, Thomas C., and Michael A. Purpera. "Light microscopy survey of extant gymnosperm root protophloem and comparison with basal angiosperms." Botany 92, no. 5 (May 2014): 388–401. http://dx.doi.org/10.1139/cjb-2013-0284.

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Gymnosperm root protophloem is not well understood. There is a question as to whether root protophloem cells mature as phloem parenchyma, or as sieve elements, or if within the protophloem there is an anatomical and evolutionary gradient having characteristics of both cell types. This question is relevant to understanding anatomical and physiological mechanisms that supply nutrients to the root tip. Anatomical data from a broad range of species show that gymnosperms have one to three layers of parenchymatous protophloem cells located at the vascular cylinder periphery between the pericyle and the metaphloem. In some species, these cells are associated with secretory idioblasts. Near the root apex, protophloem cells develop a large central vacuole and, in transverse sections, their radial walls tend to be radially elongated. When mature, these cells are highly longitudinally elongated. Only these cells exhibit surging toward the root apex during chemical fixation. These data indicate that protophloem of gymnosperm roots lacks sieve elements. Because of its distinctive anatomical characteristics and the absence of sieve elements, gymnosperm root protophloem is a vegetative synapomorphy among extant species. The restriction of this tissue type to gymnosperms supports the hypothesis that it originated in a progenitor of that clade.

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Bechtel, Achim, and Doris Groß. "Insights into floral and climatic changes from biomarker and isotopic composition of land plant organic matter – A review." Review of the Bulgarian Geological Society 85, no. 1 (July 2024): 67–70. http://dx.doi.org/10.52215/rev.bgs.2024.85.1.67.

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Biomarkers and isotopic composition of coal and plant tissue enable insights into floral assemblage and paleoenvironment. Abundance, distribution, and d13C values of leaf wax lipids (i.e. n-alkanes) differ between angiosperm and gymnosperm plants. Terpenoid hydrocarbons are used to assess the contributions of gymnosperms versus angiosperms. The influence of varying contributions of angiosperms and gymnosperms on d13C of coal can be overcome by the analyses of fossil wood remains for their isotopic composition. Angiosperms and gymnosperms show similar H-isotope fractionation between n-alkanes and water. Diterpenoids yield lower d2H values compared to angiosperm-derived triterpenoids, due to different biosynthetic pathways. Differences in mean annual precipitation affect d13C of bulk leaf organic matter. Co-variations in d13C and d2H of lipids reflect changes in water availability to the plants. Temperature variations, based on branched glycerol dialkyl glycerol tetraethers (brGDGTs), and d2H values of n-C29 alkane from Lake Van sediments reveal warm-humid climate during interglacials and cooler and drier climate during glacials. Based on the methylation of brGDGTs, a calibrated paleothermometer is available for peats and lignites.

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Burrows, Geoffrey E. "Gymnosperm Resprouting—A Review." Plants 10, no. 12 (November 23, 2021): 2551. http://dx.doi.org/10.3390/plants10122551.

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Gymnosperms are generally regarded as poor resprouters, especially when compared to angiosperms and particularly following major disturbance. However, is it this clear-cut? This review investigates two main aspects of gymnosperm resprouting: (i) various papers have provided exceptions to the above generalization—how frequent are these exceptions and are there any taxonomic trends?; and (ii) assuming gymnosperms are poor resprouters are there any anatomical or physiological reasons why this is the case? Five of six non-coniferous gymnosperm genera and 24 of 80 conifer genera had at least one species with a well-developed resprouting capability. This was a wider range than would be expected from the usual observation ‘gymnosperms are poor resprouters’. All conifer families had at least three resprouting genera, except the monospecific Sciadopityaceae. Apart from the aboveground stem, buds were also recorded arising from more specialised structures (e.g., lignotubers, tubers, burls and underground stems). In some larger genera it appeared that only a relatively small proportion of species were resprouters and often only when young. The poor resprouting performance of mature plants may stem from a high proportion of apparently ‘blank’ leaf axils. Axillary meristems have been recorded in a wide range of conifer species, but they often did not form an apical dome, leaf primordia or vascular connections. Buds or meristems that did form often abscised at an early stage. While this review has confirmed that conifers do not resprout to the same degree as angiosperms, it was found that a wide diversity of gymnosperm genera can recover vegetatively after substantial disturbance. Further structural studies are needed, especially of: (i) apparently blank leaf axils and the initial development of axillary meristems; (ii) specialised regeneration structures; and (iii) why high variability can occur in the resprouting capacity within species of a single genus and within genera of the same family.

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Farjon, Aljos, Chhaya Biswas, and B. M. Johri. "The Gymnosperms." Kew Bulletin 54, no. 2 (1999): 491. http://dx.doi.org/10.2307/4115833.

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Pandey, Bikram, Nirdesh Nepal, Salina Tripathi, Kaiwen Pan, Mohammed A. Dakhil, Arbindra Timilsina, Meta F. Justine, Saroj Koirala, and Kamal B. Nepali. "Distribution Pattern of Gymnosperms’ Richness in Nepal: Effect of Environmental Constrains along Elevational Gradients." Plants 9, no. 5 (May 14, 2020): 625. http://dx.doi.org/10.3390/plants9050625.

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Understanding the pattern of species distribution and the underlying mechanism is essential for conservation planning. Several climatic variables determine the species diversity, and the dependency of species on climate motivates ecologists and bio-geographers to explain the richness patterns along with elevation and environmental correlates. We used interpolated elevational distribution data to examine the relative importance of climatic variables in determining the species richness pattern of 26 species of gymnosperms in the longest elevation gradients in the world. Thirteen environmental variables were divided into three predictors set representing each hypothesis model (energy-water, physical-tolerance, and climatic-seasonality); to explain the species richness pattern of gymnosperms along the elevational gradient. We performed generalized linear models and variation partitioning to evaluate the relevant role of environmental variables on species richness patterns. Our findings showed that the gymnosperms’ richness formed a hump-shaped distribution pattern. The individual effect of energy-water predictor set was identified as the primary determinant of species richness. While, the joint effects of energy-water and physical-tolerance predictors have explained highest variations in gymnosperm distribution. The multiple environmental indicators are essential drivers of species distribution and have direct implications in understanding the effect of climate change on the species richness pattern.

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Qu, Xiao-Jian, Shou-Jin Fan, Susann Wicke, and Ting-Shuang Yi. "Plastome Reduction in the Only Parasitic Gymnosperm Parasitaxus Is Due to Losses of Photosynthesis but Not Housekeeping Genes and Apparently Involves the Secondary Gain of a Large Inverted Repeat." Genome Biology and Evolution 11, no. 10 (August 27, 2019): 2789–96. http://dx.doi.org/10.1093/gbe/evz187.

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Abstract Plastid genomes (plastomes) of parasitic plants undergo dramatic reductions as the need for photosynthesis relaxes. Here, we report the plastome of the only known heterotrophic gymnosperm Parasitaxus usta (Podocarpaceae). With 68 unique genes, of which 33 encode proteins, 31 tRNAs, and four rRNAs in a plastome of 85.3-kb length, Parasitaxus has both the smallest and the functionally least capable plastid genome of gymnosperms. Although the heterotroph retains chlorophyll, all genes for photosynthesis are physically or functionally lost, making photosynthetic energy gain impossible. The pseudogenization of the three plastome-encoded light-independent chlorophyll biosynthesis genes chlB, chlL, and chlN implies that Parasitaxus relies on either only the light-dependent chlorophyll biosynthesis pathway or another regulation system. Nesting within a group of gymnosperms known for the absence of the large inverted repeat regions (IRs), another unusual feature of the Parasitaxus plastome is the existence of a 9,256-bp long IR. Its short length and a gene composition that completely differs from those of IR-containing gymnosperms together suggest a regain of this critical, plastome structure-stabilizing feature. In sum, our findings highlight the particular path of lifestyle-associated reductive plastome evolution, where structural features might provide additional cues of a continued selection for plastome maintenance.

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Karas, Milan, Dominika Vešelényiová, Eva Boszorádová, Peter Nemeček, Zuzana Gerši, and Jana Moravčíková. "Comparative Analysis of Dehydrins from Woody Plant Species." Biomolecules 14, no. 3 (February 20, 2024): 250. http://dx.doi.org/10.3390/biom14030250.

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We conducted analyses on 253 protein sequences (Pfam00257) derived from 25 woody plant species, including trees, shrubs, and vines. Our goal was to gain insights into their architectural types, biochemical characteristics, and potential involvement in mitigating abiotic stresses, such as drought, cold, or salinity. The investigated protein sequences (253) comprised 221 angiosperms (85 trees/shrubs and 36 vines) and 32 gymnosperms. Our sequence analyses revealed the presence of seven architectural types: Kn, KnS, SKn, YnKn, YnSKn, FSKn, and FnKn. The FSKn type predominated in tree and shrub dehydrins of both gymnosperms and angiosperms, while the YnSKn type was more prevalent in vine dehydrins. The YnSKn and YnKn types were absent in gymnosperms. Gymnosperm dehydrins exhibited a shift towards more negative GRAVY scores and Fold Indexes. Additionally, they demonstrated a higher Lys content and lower His content. By analyzing promoter sequences in the angiosperm species, including trees, shrubs, and vines, we found that these dehydrins are induced by the ABA-dependent and light-responsive pathways. The presence of stress- and hormone-related cis-elements suggests a protective effect against dehydration, cold, or salinity. These findings could serve as a foundation for future studies on woody dehydrins, especially in the context of biotechnological applications.

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Adhatirana, Rizkia, Nina Ratna Djuita, Sulistijorini Sulistijorini, and Taufikurrahman Nasution. "Paku Epifit pada Gymnospermae di Kebun Raya Cibodas." Jurnal Sumberdaya Hayati 7, no. 2 (December 24, 2021): 49–56. http://dx.doi.org/10.29244/jsdh.7.2.49-56.

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Epiphytic ferns can be found in host trees from the Angiosperm and Gymnosperm groups. Epiphytic ferns in Angiosperm plants host have been widely studied, but there is little known for Gymnosperm plants host. The aim of this study was to identify the species of epiphytic ferns in the Gymnosperm plants host at Cibodas Botanical Garden and to analyze the diversity of epiphytic ferns based on microclimate conditions and the surface texture of Gymnosperms plants host. Epiphytic ferns diversity data was obtained using purposive random sampling method. Factors that influence the occupancy of ferns are analyzed using Principal Component Analysis. Epiphytic ferns in Gymnosperm host at Cibodas Botanical Garden were identified as 18 species including 7 family. The most dominant species of epiphytic fern is Davallia denticulata (59.45%). Diversity of epiphytic fern on Gymnosperm at Cibodas Botanical Garden is moderate (H’ = 1.81).

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Quirk, Joe, David J. Beerling, Steve A. Banwart, Gabriella Kakonyi, Maria E. Romero-Gonzalez, and Jonathan R. Leake. "Evolution of trees and mycorrhizal fungi intensifies silicate mineral weathering." Biology Letters 8, no. 6 (August 2012): 1006–11. http://dx.doi.org/10.1098/rsbl.2012.0503.

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Forested ecosystems diversified more than 350 Ma to become major engines of continental silicate weathering, regulating the Earth's atmospheric carbon dioxide concentration by driving calcium export into ocean carbonates. Our field experiments with mature trees demonstrate intensification of this weathering engine as tree lineages diversified in concert with their symbiotic mycorrhizal fungi. Preferential hyphal colonization of the calcium silicate-bearing rock, basalt, progressively increased with advancement from arbuscular mycorrhizal (AM) to later, independently evolved ectomycorrhizal (EM) fungi, and from gymnosperm to angiosperm hosts with both fungal groups. This led to ‘trenching’ of silicate mineral surfaces by AM and EM fungi, with EM gymnosperms and angiosperms releasing calcium from basalt at twice the rate of AM gymnosperms. Our findings indicate mycorrhiza-driven weathering may have originated hundreds of millions of years earlier than previously recognized and subsequently intensified with the evolution of trees and mycorrhizas to affect the Earth's long-term CO 2 and climate history.

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Averyanov, Leonid V., Tien Hiep Nguyen, Khang Nguyen Sinh, The Van Pham, Vichith Lamxay, Somchanh Bounphanmy, Shengvilai Lorphengsy, Loc Ke Phan, Soulivanh Lanorsavanh, and Khamfa Chantthavongsa. "Gymnosperms of Laos." Nordic Journal of Botany 32, no. 6 (September 10, 2014): 765–805. http://dx.doi.org/10.1111/njb.00498.

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Czeczuga, B. "Carotenoids in gymnosperms." Biochemical Systematics and Ecology 14, no. 1 (January 1986): 13–15. http://dx.doi.org/10.1016/0305-1978(86)90079-7.

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Banerji, J., and P. K. Pal. "Mesozoic plant remains from Sarnu, Barmer District, Rajasthan." Journal of Palaeosciences 35, no. (1-3) (December 31, 1986): 141–45. http://dx.doi.org/10.54991/jop.1986.1519.

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The plant assemblage includes pteridophytic as well as gymnospermic remains. Amongst the pteridophytes Phlebopteris is common with rare presence of Cladophlebis, whereas, of the gymnosperms Otozamites is frequent with rare occurrence of Pachypteris, Pagiophyllum and Brachyphyllum. The assemblage is somewhat similar to the fossil assemblage of Pariwar Formation, Jaisalmer District. On the basis of plant assemblage an Upper Jurassic age has been suggested for the Samu Hill Formation.

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Nguyen, Thi Thu Tram, Eun-Kyung Bae, Thi Ngoc Anh Tran, Hyoshin Lee, and Jae-Heung Ko. "Exploring the Seasonal Dynamics and Molecular Mechanism of Wood Formation in Gymnosperm Trees." International Journal of Molecular Sciences 24, no. 10 (May 11, 2023): 8624. http://dx.doi.org/10.3390/ijms24108624.

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Forests, comprising 31% of the Earth’s surface, play pivotal roles in regulating the carbon, water, and energy cycles. Despite being far less diverse than angiosperms, gymnosperms account for over 50% of the global woody biomass production. To sustain growth and development, gymnosperms have evolved the capacity to sense and respond to cyclical environmental signals, such as changes in photoperiod and seasonal temperature, which initiate growth (spring and summer) and dormancy (fall and winter). Cambium, the lateral meristem responsible for wood formation, is reactivated through a complex interplay among hormonal, genetic, and epigenetic factors. Temperature signals perceived in early spring induce the synthesis of several phytohormones, including auxins, cytokinins, and gibberellins, which in turn reactivate cambium cells. Additionally, microRNA-mediated genetic and epigenetic pathways modulate cambial function. As a result, the cambium becomes active during the summer, resulting in active secondary xylem (i.e., wood) production, and starts to become inactive in autumn. This review summarizes and discusses recent findings regarding the climatic, hormonal, genetic, and epigenetic regulation of wood formation in gymnosperm trees (i.e., conifers) in response to seasonal changes.

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Lu, Zhaogeng, Bei Jiang, Beibei Zhao, Xinyu Mao, Jinkai Lu, Biao Jin, and Li Wang. "Liquid profiling in plants: identification and analysis of extracellular metabolites and miRNAs in pollination drops of Ginkgo biloba." Tree Physiology 40, no. 10 (June 2, 2020): 1420–36. http://dx.doi.org/10.1093/treephys/tpaa073.

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Abstract The pollination drop (PD), also known as an ovular secretion, is a critical feature of most wind-pollinated gymnosperms and function as an essential component of pollination systems. However, the metabolome and small RNAs of gymnosperm PDs are largely unknown. We employed gas chromatography–mass spectrometry to identify a total of 101 metabolites in Ginkgo biloba L. PDs. The most abundant metabolites were sugars (45.70%), followed by organic acids (15.94%) and alcohols (15.39%) involved in carbohydrate metabolism, glycine, serine and threonine metabolism. Through pollen culture of the PDs, we further demonstrated that the metabolic components of PDs are indispensable for pollen germination and growth; in particular, organic acids and fatty acids play defensive roles against microbial activity. In addition, we successfully constructed a small RNA library and detected 45 known and 550 novel miRNAs in G. biloba PDs. Interestingly, in a comparative analysis of miRNA expression between PDs and ovules, we found that most of the known miRNAs identified in PDs were also expressed in the ovules, implying that miRNAs in PDs may originate from ovules. Further, combining with potential target prediction, degradome validation and transcriptome sequencing, we identified that the interactions of several known miRNAs and their targets in PDs are involved in carbohydrate metabolism, hormone signaling and defense response pathways, consistent with the metabolomics results. Our results broaden the knowledge of metabolite profiling and potential functional roles in gymnosperm PDs and provide the first evidence of extracellular miRNA functions in ovular secretions from gymnosperms.

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Wang, Jian R. "Spring and summer hydraulic conductivity of 14 woody species of the sub-boreal forest in British Columbia." Canadian Journal of Forest Research 35, no. 11 (November 1, 2005): 2727–33. http://dx.doi.org/10.1139/x05-176.

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Four hydraulic properties of the xylem, the Huber value (HV), hydraulic conductivity (Kh), and specific (Ks) and leaf-specific hydraulic conductivity (K1) were studied during the spring before leaf-out and during the summer after full leaf-out for 14 co-occurring tree and shrub species in the sub-boreal mixedwood forests of central British Columbia. The 14 studied species were divided into deciduous and evergreen angiosperm and gymnosperm groups, including one deciduous gymnosperm species, the tamarack, Larix laricina (Du Roi) K. Koch. I tested whether species with different life forms and classification divisions have different hydraulic properties. HVs were statistically similar for all angiosperms but significantly different among gymnosperms. Long-lived, late-successional species had higher HVs than pioneer and early-successional species. Ks and K1 values for all species except one, subalpine fir, Abies lasiocarpa var. lasiocarpa (Hook.) Nutt., were significantly higher in the spring than in the summer. Conductivity was higher in angiosperms than in gymnosperms in both the spring and the summer, and was highest in deciduous species in both seasons. The results indicate that requirements for mechanical strength may account for the high HVs in conifers, and that the high HVs compensate for low Ks and K1 values. The high hydraulic conductivities observed in the spring coincide with high water availability and high water demand by trees with emerging leaves. The subsequent reduction in Ks and K1 values could be caused by drought-induced embolism and cavitation in early summer.

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Hamal, Jaya Prakash, and Mukesh Kumar Chettri. "AIR POLLUTION TOLERANCE INDEX OF SOME SELECTED GYMNOSPERM SPECIES ALONG THE ROAD SIDE OF KATHMANDU VALLEY, NEPAL." Ecoprint: An International Journal of Ecology 24 (December 5, 2017): 13–19. http://dx.doi.org/10.3126/eco.v24i0.20642.

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Response of plants towards air pollution is assessed by air pollution tolerance index (APTI). Four species of Gymnosperms (Thuja orientiales, Cedrus deodara, Pinus roxburghii and Araucaria bidwillii) were evaluated for APTI. Leaves were collected during winter season from polluted sites (Airport, Dhumbarahi, Jawalakhel, Ratnapark, and Sankhapark) and less polluted site (Narayanthan) of Kathmandu valley. Of four gymnosperm species collected from road side, all species (Cedrus deodara, Araucaria bidwillii, Thuja orientiales and Pinus roxburghii) showed high value of APTI (i.e., more than 8), indicating their resistance to air pollution.ECOPRINT 24: 13-19, 2017

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Zimmerman, P. A., N. Lang-Unnasch, and C. A. Cullis. "Polymorphic regions in plant genomes detected by an M13 probe." Genome 32, no. 5 (October 1, 1989): 824–28. http://dx.doi.org/10.1139/g89-517.

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A sequence containing two clusters of 15 base pair repeats from the protein III gene in the bacteriophage M13 has been shown to detect hypervariable minisatellites in many animal species. We have shown that this M13 fragment will detect similar sequences in higher plants including monocots, dicots, and gymnosperms. In addition, polymorphisms were demonstrated in three dicot species. The amount of this sequence has no relationship with the size of the genome, chromosome number, or amount of repetitive DNA in the species tested.Key words: bacteriophage M13, monocot, dicot, gymnosperm, restriction fragment length polymorphism.

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Kiorapostolou, Natasa, Luca Da Sois, Francesco Petruzzellis, Tadeja Savi, Patrizia Trifilò, Andrea Nardini, and Giai Petit. "Vulnerability to xylem embolism correlates to wood parenchyma fraction in angiosperms but not in gymnosperms." Tree Physiology 39, no. 10 (July 23, 2019): 1675–84. http://dx.doi.org/10.1093/treephys/tpz068.

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Abstract Understanding which structural and functional traits are linked to species’ vulnerability to embolism formation (P50) may provide fundamental knowledge on plant strategies to maintain an efficient water transport. We measured P50, wood density (WD), mean conduit area, conduit density, percentage areas occupied by vessels, parenchyma cells (PATOT) and fibers (FA) on branches of angiosperm and gymnosperm species. Moreover, we compiled a dataset of published hydraulic and anatomical data to be compared with our results. Species more vulnerable to embolism had lower WD. In angiosperms, the variability in WD was better explained by PATOT and FA, which were highly correlated. Angiosperms with a higher P50 (less negative) had a higher amount of PATOT and total amount of nonstructural carbohydrates. Instead, in gymnosperms, P50 vs PATOT was not significant. The correlation between PATOT and P50 might have a biological meaning and also suggests that the causality of the commonly observed relationship of WD vs P50 is indirect and dependent on the parenchyma fraction. Our study suggests that angiosperms have a potential active embolism reversal capacity in which parenchyma has an important role, while in gymnosperms this might not be the case.

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Ghaffari, Tayyebeh, Joo-Hyun Hong, Solmaz Asnaashari, Safar Farajnia, Abbas Delazar, Hamed Hamishehkar, and Ki-Hyun Kim. "Natural Phytochemicals Derived from Gymnosperms in the Prevention and Treatment of Cancers." International Journal of Molecular Sciences 22, no. 12 (June 21, 2021): 6636. http://dx.doi.org/10.3390/ijms22126636.

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The incidence of various types of cancer is increasing globally. To reduce the critical side effects of cancer chemotherapy, naturally derived compounds have been considered for cancer treatment. Gymnosperms are a group of plants found worldwide that have traditionally been used for therapeutic applications. Paclitaxel is a commercially available anticancer drug derived from gymnosperms. Other natural compounds with anticancer activities, such as pinostrobin and pinocembrin, are extracted from pine heartwood, and pycnogenol and enzogenol from pine bark. Gymnosperms have great potential for further study for the discovery of new anticancer compounds. This review aims to provide a rational understanding and the latest developments in potential anticancer compounds derived from gymnosperms.

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Agrawal, Teena, and Priyanka Danai. "Fossil Gymnosperms-A Review." International Journal of Current Research and Academic Review 5, no. 6 (June 20, 2017): 49–55. http://dx.doi.org/10.20546/ijcrar.2017.506.007.

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Ahuja, M. Raj. "Polyploidy in Gymnosperms: Revisited." Silvae Genetica 54, no. 1-6 (December 1, 2005): 59–69. http://dx.doi.org/10.1515/sg-2005-0010.

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Abstract There are only a few natural polyploids in gymnosperms. These have been reported in Ephera spp. (Gnetales), and Juniperus chinensis ‘Pfitzeriana’ (2n = 4x = 44), Fitzroya cupressoides (2n = 4x = 44), and the only hexaploid conifer Sequoia sempervirens (2n = 6x = 66) (Coniferales). Sporadic polyploids and aneuploids occur at a very low frequency in nurseries in conifers, but most of them show growth abnormalities, remain dwarf, and may not reach maturity. One exception is an autotetraploid tree of Larix decidua (2n = 4x = 48) that has survived in a private estate in Denmark. Colchicine-induced polyploids (colchiploids) have been produced in a several genera of conifers, including, Pinus, Picea, and Larix. These colchiploids (Co) were hybridized to untreated diploids to produce C1 and C2 generations to investigate their chromosome behavior. The colchiploids showed a wide range of chromosome variability, ranging from diploids, triploids, and tetraploids, and many were mixoploids. The colchiploids also show growth retardation, remain dwarf, and their future potential applications in forestry remains uncertain. However, genetic variability in the colchiploids still offers prospects for isolating genetically stable new genotypes. Even though polyploidy is rare in extant conifers, is it possible that ancient polyploidy or paleopolyploidy, that is prevalent in angiosperms, has also played a role in the evolution of conifers. In this paper we shall review the current status of polyploidy in gymnosperms.

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Rastogi, S., and D. Ohri. "B-Chromosomes in Gymnosperms." Silvae Genetica 68, no. 1 (January 1, 2019): 51–54. http://dx.doi.org/10.2478/sg-2019-0009.

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Abstract B-chromosomes show a non-random distribution in different taxa of gymnosperms. They are generally smaller and show similar centromeric position as the normal complement and are heterochromatic in nature and may show DAPI or CMA banding. They are generally devoid of any gene content, do not pair at meiosis and show accumulation through female line. They show incremental effect on genome size and some adaptive value in particular ecological conditions.

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Owens, John N., Vani Hardev, and James E. Eckenwalder. "Sex expression in gymnosperms." Critical Reviews in Plant Sciences 9, no. 4 (January 1990): 281–94. http://dx.doi.org/10.1080/07352689009382291.

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Ohri, Deepak, and Shubhi Rastogi. "Sex determination in gymnosperms." Nucleus 63, no. 1 (September 21, 2019): 75–80. http://dx.doi.org/10.1007/s13237-019-00297-w.

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Ohri, D., and T. N. Khoshoo. "Genome size in gymnosperms." Plant Systematics and Evolution 153, no. 1-2 (1986): 119–32. http://dx.doi.org/10.1007/bf00989421.

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Fastovsky, David E. "Dinosaur Architectural Adaptations for a Gymnosperm-Dominated World." Paleontological Society Papers 6 (November 2000): 183–208. http://dx.doi.org/10.1017/s1089332600000760.

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The middle jurassic through Cretaceous was the heyday of gymnosperms. Gymnosperms—a paraphyletic group of seed-bearing, non-flowering vascular plants including conifers, ginkgos, seed ferns, cycads, and cycadeoids—comprised as much as 80% of global floras throughout this time interval. Even the much-heralded rise of angiosperms in the mid- to Late Cretaceous did little to shake the Mesozoic dominance among terrestrial floras of gymnosperms (in particular, conifers; see Tiffney, 1997). By the end of the Cretaceous, angiosperms comprised—depending upon whose estimate is being used—somewhere between 40 and 60% of the world's floras (Lidgard and Crane, 1988; Tiffney, 1997), leaving plenty of ecospace available for gymnosperms. The lower part of Figure 1, redrawn from Tiffney (1997), documents the flux of the major groups of plants throughout the Late Triassic-through-latest Cretaceous interval. The figure reaffirms that in the Mesozoic, gymnosperms were the floral force to be reckoned with.

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Li, Zheng, Anthony E. Baniaga, Emily B. Sessa, Moira Scascitelli, Sean W. Graham, Loren H. Rieseberg, and Michael S. Barker. "Early genome duplications in conifers and other seed plants." Science Advances 1, no. 10 (November 2015): e1501084. http://dx.doi.org/10.1126/sciadv.1501084.

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Polyploidy is a common mode of speciation and evolution in angiosperms (flowering plants). In contrast, there is little evidence to date that whole genome duplication (WGD) has played a significant role in the evolution of their putative extant sister lineage, the gymnosperms. Recent analyses of the spruce genome, the first published conifer genome, failed to detect evidence of WGDs in gene age distributions and attributed many aspects of conifer biology to a lack of WGDs. We present evidence for three ancient genome duplications during the evolution of gymnosperms, based on phylogenomic analyses of transcriptomes from 24 gymnosperms and 3 outgroups. We use a new algorithm to place these WGD events in phylogenetic context: two in the ancestry of major conifer clades (Pinaceae and cupressophyte conifers) and one inWelwitschia(Gnetales). We also confirm that a WGD hypothesized to be restricted to seed plants is indeed not shared with ferns and relatives (monilophytes), a result that was unclear in earlier studies. Contrary to previous genomic research that reported an absence of polyploidy in the ancestry of contemporary gymnosperms, our analyses indicate that polyploidy has contributed to the evolution of conifers and other gymnosperms. As in the flowering plants, the evolution of the large genome sizes of gymnosperms involved both polyploidy and repetitive element activity.

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XUE, XIAO-FENG, and XIN-YU LIU. "Three new species of Calepitrimerus (Acari: Eriophyidae) from China." Zootaxa 5133, no. 2 (May 4, 2022): 279–92. http://dx.doi.org/10.11646/zootaxa.5133.2.8.

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The genus Calepitrimerus (Acari: Eriophyoidea) comprise more than 90 extant species. Most species infest angiosperms, while only five were reported from gymnosperms. Herein, we describe and illustrate three new species of the genus Calepitrimerus from China: two from angiosperms, C. huayanlingense sp. nov. on Ficus erecta (Moraceae), C. cryptocaryaer sp. nov. on Cryptocarya concinna (Lauraceae), and one from a gymnosperm, C. liuanense sp. nov. on Cryptomeria japonica (Cupressaceae). All new species were found vagrant on lower surfaces of their hosts’ leaves, albeit inducing no apparent symptom. A list of Calepitrimerus species in China is tabulated.

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Denne, Pat, and Siân Turner. "Ray Structure Differences between Rootwood and Stemwood in a Range of Softwood Species." IAWA Journal 30, no. 1 (2009): 71–80. http://dx.doi.org/10.1163/22941932-90000204.

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Differences between the ray structure of rootwood and stemwood were analysed in 11 species from 5 families of gymnosperms. Rootwood was consistently found to have fewer ray tracheids, with ray parenchyma cells which were taller axially, wider tangentially, but shorter radially, and had more pits per cross-field than stemwood. A scale for quantifying types of cross-field pitting is proposed, and statistically significant differences in type and diameter of cross-field pitting were found between rootwood and stemwood of most species sampled. These structural differences have practical implications for identification of gymnosperm roots, and for distinguishing between rootwood and stemwood.

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Mehrotra, R. C., and N. Awasthi. "Status of gymnosperms in the Indian Tertiary flora." Journal of Palaeosciences 43, no. 1-3 (December 31, 1994): 82–88. http://dx.doi.org/10.54991/jop.1994.1167.

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Gymnosperms, the most dominated group of plants during Mesozoic, were meagerly represented in Indian Tertiary flora. The Tertiary gymnosperms occur in the form of petrified woods, cones and leaf impressions, besides pollen referable to the families Podocarpaceae, Araucariaceae and Cycadaceae. Until Late Cretaceous-Early Palaeocene the gymnosperms were widely distributed in the Indian peninsula. However, during Tertiary they declined to such an extent that towards the close of Pliocene Araucariaceae totally disappeared from Indian sub-continent. The podocarpaceae too, is now on the verge of extinction as it occurs in the restricted areas in northeast India and Nilgiri Hills in southern India. The cause of decline of these tropical gymnosperms and advent of the northern temperature members in the Indian subcontinent during Tertiary are discussed.

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Lupia, Richard, Scott Lidgard, and Peter R. Crane. "Comparing palynological abundance and diversity: implications for biotic replacement during the Cretaceous angiosperm radiation." Paleobiology 25, no. 3 (1999): 305–40. http://dx.doi.org/10.1017/s009483730002131x.

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The Cretaceous radiation of angiosperms initiated a major reorganization of terrestrial plant communities as dominance by pteridophytic and gymnospermic groups eventually gave way to dominance by angiosperms. Previously, patterns of biotic replacement have been assessed using measures based on taxonomic diversity data. However, using measures of both abundance and diversity to investigate replacement patterns provides more information about macroecological change in the fossil record than either can provide alone. Analyses of an updated and expanded database of North American palynological samples from Cretaceous sediments document a rapid increase in angiosperm diversity and abundance within individual fossil palynofloras (representing local/subregional vegetation). New analyses of floristic diversity patterns support previous results and indicate that the decline of free-sporing plants is more pronounced than the decline of gymnosperms. In contrast, analyses of abundance data appear to show that the decline of gymnosperms is far more pronounced than the decline of free-sporing plants. Detailed examination of both data sets segregated by paleolatitude shows that this apparent contradiction reflects biogeographical differences in the patterns of vegetational change (e.g., free-sporing plants declined in abundance at lower latitudes) as well as sampling bias (e.g., greater sampling in the northern region in the Late Cretaceous). Analyses accounting for these biases support the conclusion that as angiosperms radiated, free-sporing plants rather than gymnosperms (in this case, mainly conifers) experienced the most pronounced decline. A thorough understanding of the Cretaceous radiation of angiosperms will require both abundance and diversity data. It also will require expanding the analyses presented here into other geographic regions as well as sampling more completely at all spatial scales.

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Prasad, Mahesh, E. G. Khare, K. Ambwani, and Sanjai Kumar Singh. "Palynological studies in the Lower Siwalik sediments of Nahan, Himachal Pradesh, India." Journal of Palaeosciences 60, no. (1-2) (December 31, 2011): 323–33. http://dx.doi.org/10.54991/jop.2011.179.

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The present study highlights for the first time recovery of the Lower Siwalik palynoassemblage comprising algal, fungal, pteridophytic spores, gymnosperms and angiosperm pollen from an exposed section on Nahan-Ponta Saheb Road, Himachal Pradesh. The qualitative and quantitative analysis revealed that the algal and fungal spores are dominated by angiosperms, followed by pteridophytes and gymnosperms. The angiosperms show their maximum percentage in the total assemblage. Algal remains are feeble in number. The important taxa recovered are: Psiloschizosporis microreticulatus sp. nov., Notothyrites sp., Lacrimasporonites barrelicus sp. nov, Lygodiumsporites lakiensis Saxena, Polypodiisporites perverrucatus Nandi, Crassoretitriletes vanraadshooveni Germeraad et al., Todisporites kutchensis Sah & Kar, Pinuspollenites crestus Kar, Araucariacites sp., Podocarpidites ruminatus sp. nov., Palmaepollenites kutchensis Venkatachala & Kar, Palmidites naviculus Kar & Saxena, Palaeomalvaceaepollis mammilatus Kar, Retimonosulcites circularis sp. nov., Retitribrevicolporites nahanensis sp. nov., Ligulifloraedites pilatus Kar, Pseudonothofagidites kutchensis Kar, Meliapollis quadrangularis (Ramanujam) Sah & Kar. On the basis of their affinities with modern equivalents, a humid tropical to subtropical climate has been indicated encompassing some fresh water bodies during the deposition of these sediments in this area. The gymnospermous taxa (cf. Pinus, Podocarpus and Araucaria) were possibly derived from uplands of nearby area.

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Ran, Jin-Hua, Ting-Ting Shen, Ming-Ming Wang, and Xiao-Quan Wang. "Phylogenomics resolves the deep phylogeny of seed plants and indicates partial convergent or homoplastic evolution between Gnetales and angiosperms." Proceedings of the Royal Society B: Biological Sciences 285, no. 1881 (June 20, 2018): 20181012. http://dx.doi.org/10.1098/rspb.2018.1012.

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After decades of molecular phylogenetic studies, the deep phylogeny of gymnosperms has not been resolved, and the phylogenetic placement of Gnetales remains one of the most controversial issues in seed plant evolution. To resolve the deep phylogeny of seed plants and to address the sources of phylogenetic conflict, we conducted a phylotranscriptomic study with a sampling of all 13 families of gymnosperms and main lineages of angiosperms. Multiple datasets containing up to 1 296 042 sites across 1308 loci were analysed, using concatenation and coalescence approaches. Our study generated a consistent and well-resolved phylogeny of seed plants, which places Gnetales as sister to Pinaceae and thus supports the Gnepine hypothesis. Cycads plus Ginkgo is sister to the remaining gymnosperms. We also found that Gnetales and angiosperms have similar molecular evolutionary rates, which are much higher than those of other gymnosperms. This implies that Gnetales and angiosperms might have experienced similar selective pressures in evolutionary histories. Convergent molecular evolution or homoplasy is partially responsible for the phylogenetic conflicts in seed plants. Our study provides a robustly reconstructed backbone phylogeny that is important for future molecular and morphological studies of seed plants, in particular gymnosperms, in the light of evolution.

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Dar, Abdul Rashid, Lubna Andleeb, Ghulam Hassan Dar, Mohammad Rafiq Wani, Afroza Akhter, Naseer Hussain Shah, and Irfana Amin. "A Review of Taxonomic Perspective of Diversity in Gymnosperms of Kashmir Himalaya." Biological Sciences - PJSIR 64, no. 1 (March 3, 2021): 94–108. http://dx.doi.org/10.52763/pjsir.biol.sci.64.1.2021.94.108.

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Varied floristic works relevant to Kashmir Himalaya were thoroughly examined to compile taxonomic contributions of various taxonomists viz. a viz. diversity in gymnosperms of this region. Extensive field surveys and standard taxonomic methods were used to locate, collect, identify and prepare an updated list of the target group. A total of 25 species of gymnosperms belonging to 13 genera in 6 families and 4 orders have been documented from the Kashmir Himalaya. Wild gymnosperms are represented by 11 species with conifers forming the most dominant group. Among families, Pinaceae is highest represented with 6 species, while Taxaceae is least represented. Cultivated gymnosperms exceed wild growing species, and Cupressaceae is most dominant with 9 species whereas Ginkgoaceae is least represented. Out 25 species 19 (7 wild + 12 cultivated) are trees, 5 (3 wild + 2 cultivated) are shrubs and only 1 is sub-shrub.

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Viracheva, Ljubov Leonidovna, and Ljubov Andreevna Ivanova. "Plants of the Gymnosperms (Gymnospermae) in the Greenhouse of the Polar-Alpine Botanical Garden." HORTUS BOTANICUS 16, no. 16 (January 2021): 168–77. http://dx.doi.org/10.15393/j4.art.2021.6906.

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Nyman, Tommi, Renske E. Onstein, Daniele Silvestro, Saskia Wutke, Andreas Taeger, Niklas Wahlberg, Stephan M. Blank, and Tobias Malm. "The early wasp plucks the flower: disparate extant diversity of sawfly superfamilies (Hymenoptera: ‘Symphyta’) may reflect asynchronous switching to angiosperm hosts." Biological Journal of the Linnean Society 128, no. 1 (July 1, 2019): 1–19. http://dx.doi.org/10.1093/biolinnean/blz071.

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AbstractThe insect order Hymenoptera originated during the Permian nearly 300 Mya. Ancestrally herbivorous hymenopteran lineages today make up the paraphyletic suborder ‘Symphyta’, which encompasses c. 8200 species with very diverse host-plant associations. We use phylogeny-based statistical analyses to explore the drivers of diversity dynamics within the ‘Symphyta’, with a particular focus on the hypothesis that diversification of herbivorous insects has been driven by the explosive radiation of angiosperms during and after the Cretaceous. Our ancestral-state estimates reveal that the first symphytans fed on gymnosperms, and that shifts onto angiosperms and pteridophytes – and back – have occurred at different time intervals in different groups. Trait-dependent analyses indicate that average net diversification rates do not differ between symphytan lineages feeding on angiosperms, gymnosperms or pteridophytes, but trait-independent models show that the highest diversification rates are found in a few angiosperm-feeding lineages that may have been favoured by the radiations of their host taxa during the Cenozoic. Intriguingly, lineages-through-time plots show signs of an early Cretaceous mass extinction, with a recovery starting first in angiosperm-associated clades. Hence, the oft-invoked assumption of herbivore diversification driven by the rise of flowering plants may overlook a Cretaceous global turnover in insect herbivore communities during the rapid displacement of gymnosperm- and pteridophyte-dominated floras by angiosperms.

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Dillhoff, Richard M., Estella B. Leopold, and Steven R. Manchester. "The McAbee flora of British Columbia and its relation to the Early-Middle Eocene Okanagan Highlands flora of the Pacific Northwest." Canadian Journal of Earth Sciences 42, no. 2 (February 1, 2005): 151–66. http://dx.doi.org/10.1139/e04-084.

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Megafossils and pollen data are used to compare the flora found at the McAbee site, located near the town of Cache Creek, British Columbia, to six other well-collected Eocene lacustrine floras of Washington and western British Columbia. A diverse flora is found at McAbee consisting of at least 87 taxa. Gymnosperms are common, including sixteen separate species, 14 conifers and two ginkgos. A minimum of 67 angiosperm genera are represented in the flora, many yet to be described. The dominant dicotyledonous elements of the leaf assemblage at McAbee include Fagus (also represented by nuts and cupules) with Ulmus and representatives of the Betulaceae, especially Betula and Alnus. The confirmation of Fagus, also rarely found from sites at Princeton, British Columbia, and Republic, Washington, provides the oldest well-documented occurrence of the genus, predating the Early Oligocene records of Fagus previously reported for North America, Asia, and Europe. Data provided by pollen analysis broadens our knowledge of the McAbee flora. Angiosperm pollen typically predominates over gymnosperms with the Ulmoideae and Betulaceae being the most common angiosperm pollen types. Members of the Pinaceae dominate the gymnosperm pollen record. Paleoclimatic estimates for McAbee are slightly cooler than for the Republic and Princeton localities and thermophilic elements, such as Sabal found at Princeton or Ensete and Zamiaceae found at Republic are not known from McAbee.

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Ohri, Deepak. "Polyploidy in Gymnosperms-A Reappraisal." Silvae Genetica 70, no. 1 (January 1, 2021): 22–38. http://dx.doi.org/10.2478/sg-2021-0003.

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Abstract:

Abstract Recent polyploidy in gymnosperms is unusually scarce being present in only 9.80 % of the 714 taxa studied cytologically. Polyploid forms are represented by sporadic seedlings and individual trees, intraspecific polyploidy in cultivation or in wild and entirely polyploid species and genera. Polyploidy shows a non-random distribution in different genera being mostly prevalent in Ephedra and Juniperus, besides the classic examples of Sequoia and Fitzroya. Remarkably, both Ephedra and Juniperus show adaptive radiation by interspecific hybridization followed by polyploidy while in Ginkgo viable polyploid cytotypes are found in cultivation. Induced polyploidy has not provided any tangible results in the past but recent attempts on certain genera of Cupressaceae hold some promise of producing cultivars for horticulture trade. Lastly, various evidences derived from cytological analysis, fossil pollen, guard cells and comparative genomic studies indicating the occurrence of paleopolyploidy have been discussed.

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49

Stevenson, Dennis Wm, and Charles B. Beck. "Origin and Evolution of Gymnosperms." Brittonia 42, no. 2 (April 1990): 161. http://dx.doi.org/10.2307/2807637.

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50

Price, Robert, and Charles B. Beck. "Origin and Evolution of Gymnosperms." Taxon 38, no. 4 (November 1989): 611. http://dx.doi.org/10.2307/1222639.

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Journal articles on the topic 'Gymnosperms'

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