Artículos de revistas: "Pyricularia grisea"

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Zuraidah, Zuraidah, Qatrun Nida y Sri Wahyuni. "UJI ANTAGONIS BAKTERI TERHADAP CENDAWAN PATOGEN PENYAKIT BLAS". BIOTIK: Jurnal Ilmiah Biologi Teknologi dan Kependidikan 8, n.º 1 (19 de julio de 2020): 37. http://dx.doi.org/10.22373/biotik.v8i1.6667.

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Damage to leaves, panicles, and stems of rice plants caused by fungal pathogens, Pyricularia grisea, which causes Blas. Control of this disease by the use of biological agents in the form of bacteria which is Bacillus cereus and Pseudomonas aeruginosa, and consortium. This research aims to determine the ability of these bacterial isolates to inhibit the growth of Pyricularia grisea. This research was arranged in a Completely Randomized Design (CRD) with 4 treatments and 3 replications. The working procedures in this research were sampling of pathogenic fungi, making Pyricularia grisea liquid inoculum, and testing bacterial antagonists for pathogenic fungi in vitro. Analysis of variance (ANAVA) was used, with Fcount = 802.66 and Ftable = 3.48 with a significant level of α = 0.05 (5%) proved that the isolates of the bacteria Bacillus cereus and Pseudomonas aeruginosa could play an antagonistic role towards the fungus Pyricularia grisea. The results of this research indicate that bacterial isolates were able to inhibit the growth of Pyricularia grisea by the formation of the largest average clear zone in the treatment of Bacillus cereus bacteria which was 9.57 mm. The clear zone in the fungicide is 9.53 mm, the consortium is 9.37 mm, and the Pseudomonas aeruginosa is 8.2 mm.

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Zuraidah, Zuraidah y Sri Wahyuni. "Uji Daya Hambat Beberapa Ekstrak Bahan Alami Terhadap Pertumbuhan Cendawan Pyricularia grisea". BIOTIK: Jurnal Ilmiah Biologi Teknologi dan Kependidikan 6, n.º 2 (28 de noviembre de 2019): 81. http://dx.doi.org/10.22373/biotik.v6i2.5611.

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Pyricularia grisea is a pathogenic fungus which causing rice blast disease that affected leaf, stems and rice panicles of rice plant. A possible option to reduce the use of synthetic chemical fungicide in managing the blast disease is by using plant natural active ingredients to inhibit the mycelial growth of Pyricularia grisea. This research evaluated the potential uses of bay leaf, tropical almond leaf, and kaffir lime leaf extract in inhibiting pathogenic fungus Pyricularia grisea. A Completely Randomized Design (CRD) with 3 replications and 4 treatments were used in this research. Work procedures included leaf extracts preparation, pathogenic fungi rejuvenation, growth media preparation and isolates plantation on PDA media. The parameter in this study was the diameter of the Pyricularia grisea inhibition zone. Data was analysed by analysis of variance (ANOVA) at 95% confidence interval with Duncan Multiple Range Test (DMRT) at 5% level (α = 0.05) as post hoc test if significant differences between treatments were detected using SPSS 16.0. The results of this study indicated that the highest concentration (100%) of each plant leaf extract was able to inhibit the mycelial growth of the pathogenic fungus Pyricularia grisea. The zone of inhibition of bay leaf extract was 1.77 mm, tropical almond leaf extract was 2.33 mm and lime leaf extract was 1.52 mm. The largest diameter of the inhibition zone was found on media with tropical almond leaf extract.

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Urashima, Alfredo Seiiti, Sabrina Ferreira Leite y Rafael Galbieri. "Eficiência da disseminação aérea em Pyricularia grisea". Summa Phytopathologica 33, n.º 3 (septiembre de 2007): 275–79. http://dx.doi.org/10.1590/s0100-54052007000300011.

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Pyricularia grisea (teleomorfa Magnaporthe grisea) é um patógeno que infecta mais de 80 gramíneas. No Brasil ataca importantes culturas como arroz e trigo, causando a brusone. Mais recentemente foi reportada na triticale, cultura alternativa para os produtores de trigo no sul do estado de São Paulo. Um dos principais meios de disseminação da doença é a dispersão aérea embora pouca informação esteja disponível sobre a distância que esses esporos podem atingir a partir de uma determinada fonte de inóculo. O presente trabalho teve o objetivo de avaliar a capacidade de disseminação de P. grisea a partir de um foco inicial, empregando ferramentas moleculares. A presença de clones do patógeno em campos distantes 4, 30 e 1000 metros a partir de um campo infectado sugere que esporos de um determinado foco podem atingir pelo menos essas distâncias.

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Kumar, Vipin, Prashant Mishra, Joginder Singh y Raju . "In Vitro efficacy of essential oils on mycelial growth of Magnaporthe griseaca using blast in basmati rice". International Journal of Agricultural Invention 1, n.º 02 (31 de diciembre de 2016): 170–73. http://dx.doi.org/10.46492/ijai/2016.1.2.8.

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Management of Pyriculari agrisea by eco-friendly approaches is promising. In this study the essential oils from Coriander sativum (Coriander), Azadirachta indica (Neem) and Syzygium aromaticum (Clove) were tested against Pyricularia grisea in vitro by poison food technique. The pure culture of P. grisea was allowed to grow at 300ppm, 500ppm and 1000ppm concentration of essential oils on PDA medium. Clove oil was found most effective to inhibit mycelial growth completely at 300, 500 and 1000ppm after72 hrs, 96 hrs and 120 hrs. Next effective oil was observed neem oil followed by coriander oil. This indicated that clove oil is most effective against P. oryzae pathogen. Neem and coriander oil is less effective. The results of the current study indicated that each of the three essential oils tested, reduced the radial growth of P. oryzae.

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Urashima, Alfredo Seiiti y Cristina Perbelini Silva. "Characterization of Magnaporthe grisea (Pyricularia grisea) from Black Oat in Brazil". Journal of Phytopathology 159, n.º 11-12 (28 de septiembre de 2011): 789–95. http://dx.doi.org/10.1111/j.1439-0434.2011.01844.x.

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Greer, C. A., S. C. Scardaci y R. K. Webster. "First Report of Rice Blast Caused by Pyricularia grisea in California". Plant Disease 81, n.º 9 (septiembre de 1997): 1094. http://dx.doi.org/10.1094/pdis.1997.81.9.1094a.

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Rice blast, caused by Pyricularia grisea (Cooke) Sacc., generally recognized as the most important disease of rice (Oryzae sativa L.) worldwide, was first found in the Sacramento Valley of California in 1996. Symptoms observed in commercial fields during September and October consisted mainly of darkened lesions at the panicle neck node and flag leaf collar. Many of the panicles with neck rot were partially filled or blank. Disease foci were irregular within fields and the most severely affected areas had approximately 50% of the panicle necks with symptoms. Initial identification of P. grisea was made by isolating the fungus from panicle neck nodes and leaf collars on potato dextrose agar. Subsequent identifications were made by placing symptomatic panicle neck nodes or leaf collars on moist filter paper in petri dishes to allow sporulation of the fungus. P. grisea was consistently recovered from these tissues and was identified by conidial morphology. A survey of over 500 rice fields in five Sacramento Valley counties was conducted in September and October 1996. Rice blast was confirmed in 33 commercial fields, which are spread over an area of approximately 460 km2 in Glenn County (27 fields) and northern Colusa County (6 fields). No blast was found in Butte, Sutter, or Yolo counties. P. grisea was recovered from cvs. M-201, M-202, M-204, M-103, M-401, S-102, L-204, and Calmochi-101 and several proprietary lines. To confirm pathogenicity of P. grisea, cv. M-201 was inoculated in the greenhouse 28 days after seeding with a suspension of 20,000 conidia per ml of sterile deionized water, covered with plastic bags for 2 days, and evaluated 7 days later. P. grisea isolates from cvs. M-201, M-202, and M-204 produced typical leaf and collar blast symptoms on inoculated plants, whereas control plants remained asymptomatic. P. grisea was consistently recovered from lesions on inoculated plants. No rice cultivars currently grown in California are known to have resistance to blast.

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Lestari, Shyntiya Ayu, Umi Kalsum y Evan Purnama Ramdan. "Efikasi Beberapa Agens Hayati Terhadap Penekanan Pertumbuhan Pyricularia grisea Secara In Vitro". Agrosains : Jurnal Penelitian Agronomi 23, n.º 1 (1 de abril de 2021): 31. http://dx.doi.org/10.20961/agsjpa.v23i1.48174.

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The demand for rice as an important food crop in Indonesia is still constrained by the attack of blast disease caused by Pyricularia grisea. Controlling using synthetic chemical pesticides has a negative impact on the environment so that the use of biological agents is an alternative option. This study aims to determine the effectiveness of several biological agents against the pathogen P. grisea that causes blast disease in rice plants in vitro. The study used a completely randomized design (CRD) with 6 levels of treatment and was repeated 3 times using the dooble culture method. The results of the study showed that the inhibition of P. grisea was the highest in the treatment of P. grisea × Trichoderma sp. and P. grisea × Gliocladium sp. namely 67.04% and 51.85% compared to other treatments. The P. polymyxa and P. fluorescence treatments showed low inhibition, namely 23.70% and 28.89%. Biological agents Trichoderma sp. and Gliocladium sp. able to inhibit the growth of the fungus P. grisea. Each biological agent has a different percentage of inhibition in that caused by the inhibitory mechanism of the biological agent.

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PURCHIO, A. F. y J. J. MUCHOVEJ. "Commelina agraria: a new host of Pyricularia grisea". Plant Pathology 42, n.º 5 (octubre de 1993): 818–19. http://dx.doi.org/10.1111/j.1365-3059.1993.tb01571.x.

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Galbieri, Rafael y Alfredo Seiiti Urashima. "Caracterização, compatibilidade e ocorrência de reprodução sexual entre isolados de Pyricularia grisea de diferentes hospedeiros". Summa Phytopathologica 34, n.º 1 (febrero de 2008): 22–28. http://dx.doi.org/10.1590/s0100-54052008000100005.

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A brusone, causada por Pyricularia grisea (teleomorfa Magnaphorthe grisea), possui uma ampla gama de hospedeiros. No Brasil, arroz, trigo, triticale e cevada são as culturas que sofrem quedas significativas de produtividade devido ao ataque desse patógeno. Além desses cereais, outras gramíneas também têm apresentado sintomas dessa doença. Os objetivos dessa pesquisa foram: a) caracterizar sexualmente isolados de P. grisea desses hospedeiros baseado na determinação do "mating type", fertilidade, sexualidade, compatibilidade sexual, b) analisar o grau de compatibilidade sexual entre isolados de brusone de trigo e de outras gramíneas, c) estudar a ocorrência da reprodução sexual em isolados de trigo. Os resultados obtidos através de ensaios "in vitro" constataram: 1) compatibilidade sexual de P. grisea do trigo com Bromus catharticus, Phalaris canariensis e X. triticosecal; 2) desbalanço entre porcentagem de MAT1-1 e MAT1-2, com predominância de MAT1-1 na população de P. grisea do trigo; 3) existência de um campo de isolados de trigo com baixa habilidade de cruzamento; 4) baixa possibilidade de ocorrência de reprodução sexual de P. grisea em campos de trigo, mesmo com existência de ambos "mating type" num mesmo campo.

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Uddin, W., G. Viji, G. L. Schumann y S. H. Boyd. "Detection of Pyricularia grisea Causing Gray Leaf Spot of Perennial Ryegrass Turf by a Rapid Immuno-Recognition Assay". Plant Disease 87, n.º 7 (julio de 2003): 772–78. http://dx.doi.org/10.1094/pdis.2003.87.7.772.

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An immuno-recognition assay using a monoclonal antibody was developed to detect Pyricularia grisea, the causal agent of gray leaf spot of perennial ryegrass (Lolium perenne). In vitro assays with isolates of P. grisea from perennial ryegrass, tall fescue (Festuca arundinacea), St. Augustinegrass (Stenotaphrum secundatum), crabgrass (Digitaria sanguinalis), finger millet (Eleusine coracana), wheat (Triticum aestivum), triticale (× Triticosecale rimpaui), and rice (Oryza sativa) showed positive reactions; however, the strength of the reactions differed among isolates. Reactions were more intense with isolates from perennial ryegrass, wheat, and triticale. All P. grisea isolates from perennial ryegrass collected from various regions of the United States showed positive reactions. P. grisea was detected at antigen dilution rates of 0.5×, 0.25×, 0.13×, 0.06×, and 0.03×. Dot-blot assays with Bipolaris sorokiniana, Colletotrichum graminicola, Curvularia lunata, Microdochium nivale, Pythium aphanidermatum, Rhizoctonia solani, or Sclerotinia homoeocarpa isolated from turfgrasses were negative. In vivo assays of symptomatic leaves of perennial ryegrass plants inoculated with P. grisea also showed positive reactions, and those inoculated with B. sorokiniana, P. aphanidermatum, R. solani, or S. homoeocarpa were negative. Intensity of reaction between the monoclonal antibody and P. grisea was proportional to disease severity in perennial ryegrass inoculated with P. grisea; however, there was no reaction in dot blots of leaf tissue collected during the latent period. P. grisea was detected in perennial ryegrass samples from golf course fairways affected by gray leaf spot in Connecticut, Massachusetts, Maine, New Jersey, Pennsylvania, and Rhode Island using this procedure. The monoclonal antibody recognition system is highly sensitive to P. grisea and can be used effectively for the rapid diagnosis of gray leaf spot of perennial ryegrass turf.

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Kumar, Vipin, Rashmi Nigam, Raju ., Yachna Gupta y Gyan Manjri Rao. "Blast disease of basmati rice and its management". International Journal of Agricultural Invention 2, n.º 01 (30 de junio de 2017): 87–91. http://dx.doi.org/10.46492/ijai/2017.2.1.20.

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Basmati rice is an important staple food grain crop in the world. Basmati rice is an important export commodity among the food grains. The biotic and abiotic factors are adversely affected the Basmati rice but Basmati rice blast caused by Pyricularia oryzae Cavara (synonym Pyricularia grisea Sacc). The anamorph of Magnaporthe grisea (Herbert), is one of the most destructive and wide spread diseases as compared to other diseases of Basmati rice. It causes leaf blast, neck blast and panicle blast of paddy. This disease generally causes yield loss of 10-20 percent but in severe cases yield loss may reach up to 80 percent. Management of blast disease using healthy seed, resistance varieties, many biological controls like as T. harzianum, T. viride and P. fluorescens @10g/kg by seed treatment and foliar spray. The chemical control by fungicides such as carbendazim, tricyclazole, isoprothilane, tebuconazole, hexaconazole reduced leaf but not neck blast; on the contrary, tricyclazole was effective against neck blast and panicle blast.

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TRINDADE, DINALDO R., LUIZ S. POLTRONIERI, FERNANDO C. ALBUQUERQUE y ANTÔNIO JOSÉ E. A. MENEZES. "Pyricularia grisea causando lesões necróticas em folhas de bananeira". Fitopatologia Brasileira 27, n.º 3 (junio de 2002): 322. http://dx.doi.org/10.1590/s0100-41582002000300019.

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PRABHU, ANNE S., ELCIO P. GUIMARÃES, MARTA C. FILIPPI, LEILA G. ARAUJO y VERIDIANO A. CUTRIM. "Expression of resistance in rice hybrids to Pyricularia grisea". Fitopatologia Brasileira 27, n.º 5 (septiembre de 2002): 454–60. http://dx.doi.org/10.1590/s0100-41582002000500003.

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Thirty-nine rice (Oryza sativa) hybrids and their restorers were assessed for vertical resistance to Pyricularia grisea in the rice blast nursery, and in artificial inoculation tests with two pathotypes, under controlled greenhouse conditions. The hybrids were developed from cytoplasmic genetic male sterile lines 046I and IR 58025A, derived from WA cytoplasm. In the rice blast nursery all hybrids showed susceptible reaction varying from 5 to 9. Compatible and incompatible leaf blast reactions of hybrids to two pathotypes, IC-1 and IB-45, were observed in inoculation tests. A majority of the hybrids were resistant when the restorer was resistant. However, seven of the 25 F1 hybrids exhibited susceptible reactions even when one of the parents was resistant to a pathotype. The partial resistance of 11 hybrids and their parents that showed compatible reactions to two pathotypes was analyzed. Differential interaction between isolates and genotypes was observed for partial resistance in relation to both disease severity and lesion number indicating the specific nature of partial resistance.

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Goulart, Augusto César Pereira, Paulo Gervini Sousa y Alfredo Seiti Urashima. "Danos em trigo causados pela infecção de Pyricularia grisea". Summa Phytopathologica 33, n.º 4 (diciembre de 2007): 358–63. http://dx.doi.org/10.1590/s0100-54052007000400007.

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Este trabalho teve por objetivo quantificar os danos no rendimento de grãos, causados pela infecção natural da brusone (Pyricularia grisea), em diferentes cultivares e linhagens de trigo, na safra agrícola de 2004, no Município de Dourados, Mato Grosso do Sul, isoladamente da ocorrência de outras doenças. Trabalhou-se em condições naturais e sem o emprego de fungicidas, em parcelas experimentais, na Embrapa Agropecuária Oeste e em Indápolis. Após o espigamento, todas as espigas de trigo com sintomas típicos da brusone (ponto preto de infecção na ráquis) foram identificadas e marcadas, em uma área de 1m². As espigas doentes e sadias foram colhidas, contadas e trilhadas separadamente. Os danos foram calculados com base na diferença entre o rendimento real e a estimativa do rendimento potencial. Os resultados mostraram que os danos e a incidência da brusone variaram de acordo com as cultivares/linhagens testadas e a região tritícola avaliada. As menores incidências da brusone foram observadas na cv. BR 18-Terena, com 27% e 42% de espigas infectadas, nos ensaios instalados na Embrapa Agropecuária Oeste e em Indápolis, respectivamente. O dano médio devido à brusone, registrado nos 20 materiais testados, foi de 387kg/ha, o que representou 10,5% do rendimento de grãos, no ensaio instalado na Embrapa Agropecuária Oeste. Em Indápolis, os danos foram maiores, atingindo, em média, 609kg/ha (13,0% do rendimento de grãos). As perdas em peso por espiga foram maiores (63,4%) quando a infecção foi precoce em comparação à infecção tardia (46,0%). Verificou-se que houve uma compensação das perdas causadas pela doença, através do melhor desenvolvimento de grãos produzidos abaixo do ponto de estrangulamento da ráquis. Observou-se, também, que em função das espigas brancas sobressaírem-se das demais, pode-se superestimar as perdas.

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Xia, Jun Q., Fleet N. Lee y Kyung S. Kim. "Monoclonal antibodies to an extracellular component of Pyricularia grisea". Canadian Journal of Botany 70, n.º 9 (1 de septiembre de 1992): 1790–97. http://dx.doi.org/10.1139/b92-222.

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Monoclonal antibodies were produced from fusions of myeloma cells with splenocytes from BALB/c mice immunized with an extract of a liquid culture fluid of an isolate of Pyricularia grisea race IB—49. The hybridomas were screened with the immunogen, and three were selected and propagated in mice for antibodies in ascites fluid. The monoclonal antibodies 3C3 and 4E10, isotype IgG3, and 10G9, isotype IgA, were characterized by indirect ELISA, Western immunoblotting, and immunoelectron microscopy. All three monoclonal antibodies reacted similarly with the antigens in various serological techniques used and did not cross-react with any unrelated fungal isolates representing 11 genera but reacted positively with all 20 races or isolates of P. grisea. The monoclonal antibodies bound to a high Mr protein component (113 × 103) in extracts of liquid culture fluids and not to conidial antigens. The epitopes recognized by the monoclonal antibodies were densely distributed in the cell walls and lomasomes of hyphae and much less so in the cytoplasm of conidia. It is suggested that the antigenic component was synthesized in the cytoplasm of fungal cells, accumulated in the lomasomes, and secreted through cell walls as an extracellular molecule. The monoclonal antibodies could detect homologous antigen at about 60 ng fungal protein/mL and a fivefold dilution of the extracts of infected rice tissue by ELISA. Key words: fungus, monoclonal antibodies, ELISA, immunoassays.

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Kim, Yun-Sik, Edward W. Dixon, Paul Vincelli y Mark L. Farman. "Field Resistance to Strobilurin (QoI) Fungicides in Pyricularia grisea Caused by Mutations in the Mitochondrial Cytochrome b Gene". Phytopathology® 93, n.º 7 (julio de 2003): 891–900. http://dx.doi.org/10.1094/phyto.2003.93.7.891.

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Gray leaf spot caused by Pyricularia grisea is a highly destructive disease of perennial ryegrass turf. Control of gray leaf spot is dependent on the use of preventative fungicide treatments. Strobilurin-based (QoI) fungicides, which inhibit the cytochrome bc1 respiratory complex, have proven to be very effective against gray leaf spot. However, in August 2000, disease was diagnosed in QoI-treated perennial ryegrass turf on golf courses in Lexington, KY, Champaign, IL, and Bloomington, IL. To determine if resistance was due to a mutation in the fungicide target, the cytochrome b gene (CYTB) was amplified from baseline and resistant isolates. Nucleotide sequence analysis revealed an intronless coding region of 1,179 bp. Isolates that were resistant to QoI fungicides possessed one of two different mutant alleles, each of which carried a single point mutation. The first mutant allele had a guanine-to-cytosine transition at nucleotide position +428, resulting in a replacement of glycine 143 by alanine (G143A). Mutant allele two exhibited a cytosine-to-adenine transversion at position +387, causing a phenylalanine-to-leucine change (F129L). Cleavable amplified polymorphic sequence analysis revealed that neither mutation was present in a collection of baseline isolates collected before QoI fungicide use and indicated that suspected QoI- resistant isolates found in 2001 in Indiana and Maryland possessed the F129L mutation. The Pyricularia grisea isolates possessing the G143A substitution were significantly more resistant to azoxystrobin and trifloxystrobin, in vitro, than those having F129L. DNA fingerprinting of resistant isolates revealed that the mutations occurred in just five genetic backgrounds, suggesting that field resistance to the QoI fungicides in Pyricularia grisea is due to a small number of ancestral mutations.

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Reges, Juliana Teodora de Assis, Matheus Mereb Negrisoli, Adriano Francis Dorigan, Vanina Lilián Castroagudín, João Leodato Nunes Maciel y Paulo Cezar Ceresini. "Pyricularia pennisetigena and P. zingibericola from invasive grasses infect signal grass, barley and wheat". Pesquisa Agropecuária Tropical 46, n.º 2 (junio de 2016): 206–14. http://dx.doi.org/10.1590/1983-40632016v4641335.

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ABSTRACT Fungal species from the Pyricularia genus are associated with blast disease in plants from the Poaceae family, causing losses in economically important crops such as rice, oat, rye, barley, wheat and triticale. This study aimed at characterizing the pathogenicity spectrum of P. pennisetigena and P. zingibericola to signal grass, barley and wheat, as well as comparing them with those from the species P. grisea and P. oryzae pathotype Triticum, which occur widely in the Brazilian agroecosystem. Twenty isolates of Pyricularia spp. were obtained from infected leaf samples of invasive plant species from wheat fields. The isolates classification into distinct Pyricularia species was done using molecular phylogeny based on actin and calmodulin genes. Pyricularia pennisetigena and P. zingibericola inoculated on plant leaves, at a concentration adjusted to 105 conidia mL-1, were pathogenic to signal grass, barley and wheat, with varying levels of aggressiveness.

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Santoso, Santoso, Anggiani Nasution y Nani Yunani. "KERAGAMAN DAN SUMBER GEN KETAHANAN VARIETAS PADI LOKAL TERHADAP PATOGEN Pyricularia grisea PENYEBAB PENYAKIT BLAS". Jurnal Ilmu-Ilmu Pertanian Indonesia 22, n.º 2 (3 de diciembre de 2020): 119–28. http://dx.doi.org/10.31186/jipi.22.2.119-128.

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[DIVERSITY AND THE SOURCE OF RESISTANCE GENE OF LOCAL RICE VARIETIES ON THE PATHOGENIC OF Pyricularia grisea CAUSE OF BLAST DISEASE]. Local rice varieties are known to have resistance or source of genes to pests even though their productivity yield is low. The pathogen of Pyricularia grisea is a cause of blast disease, which is one of the obstacles in rice production. The research aims to characterize the resistance of local rice varieties to the pathogen of P. grisea and to evaluate the virulence level of P. grisea pathogens against local rice varieties. A total of 100 local rice varieties and check varieties are susceptible and resistant namely Kencana Bali and Situ Patenggang tested their resistance to 4 dominant pathogenic of P. grisea i.e. races 033, 073, 133 and 173. Inoculation was carried out on stages 4-5 leaves or 18-21 days after seedling in a green house. The results showed a high genetic diversity of local rice varieties against pathogenic races 033, 073, 133 and 173. Based on the response of local rice varieties resistance i.e. moderately resistant (MR), resistant (R) and susceptible (S) to pathogenic races 033, 073 , 133 and 173 obtained 45 resistance response patterns. Cere Bereum varieties which are local rice varieties from West Java and Situ Patenggang resistant check varieties have a resistant response to 4 P. grisea pathogenic races used. A number of local rice varieties also show a resistant and moderately resistant response to the four pathogenic races used include Siam 11, Pare Siriendah, Menyan, Cere Manggu and Enud-Rawa Bogo. Local rice varieties Djedah and Padi Hitam (2) are local rice varieties that have a specific response of resistant or moderately resistant to race 173. Race 133 and 173 have higher virulence rates than those of races 033 and 073 on local rice varieties. The results of this study indicate that there is a great potential for the utilization of local rice varieties, as a source of resistance genes for blast disease for the assembly of rice varieties that are resistant to blast disease.

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Mello, Ana P. Amaral y Alfredo S. Urashima. "Diversidade da virulência de Pyricularia grisea num local de melhoramento genético de arroz". Fitopatologia Brasileira 28, n.º 5 (octubre de 2003): 541–43. http://dx.doi.org/10.1590/s0100-41582003000500012.

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O presente trabalho objetivou estudar a diversidade da virulência de isolados de Pyricularia grisea coletados na Estação Experimental do IAC, Mococa, estado de São Paulo. A composição das raças do fungo e sua compatibilidade com genes de resistência foram estudadas utilizando-se cultivares diferenciais de arroz (Oryza sativa) do Japão. Cinqüenta isolados monospóricos foram obtidos das panículas das cultivares IAC 201 e IAC 4440 afetadas com brusone. As raças JP 137 e JP 177 de P. grisea na cultivar de arroz de sequeiro IAC 201 e a raça JP 200 na cultivar IAC 4440, arroz irrigado, foram identificadas. Foi observada uma baixa freqüência de ocorrência de raças fisiológicas no local de seleção de linhagens de melhoramento. Enquanto todos os 25 isolados provenientes de IAC 4440 foram compatíveis somente ao gene de resistência pi-ta², os isolados de IAC 201 foram compatíveis para sete dos nove genes das diferenciais japonesas. Os resultados mostraram que somente um gene de resistência (pi-z t) foi efetivo a todos os isolados de P. grisea coletados das cultivares de arroz IAC 201 e IAC 4440.

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Puri, KD, SM Shrestha, KD Joshi y GB KC. "Reaction of Different Rice Lines Against Leaf and Neck Blast under Field Condition Of Chitwan Valley". Journal of the Institute of Agriculture and Animal Science 27 (1 de mayo de 2006): 37–44. http://dx.doi.org/10.3126/jiaas.v27i0.693.

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The severity of the rice blast disease (Pyricularia grisea) of both leaf and neck varies with different environment and it becomes destructive under favorable condition. The leaf and neck blast resistance and susceptible interaction of 30 different tropical rice lines were evaluated under low-, mid- and up-land conditions of Chitwan district and classified on the basis of disease severity with respect to susceptible check, Masuli. Of them, 5, 10, 12 and 3 rice lines were resistant to leaf blast, moderately resistant, moderately susceptible susceptible, respectively. Similarly, for the neck blast nine lines were resistant, thirteen moderately resistant, seven moderately susceptible and one was susceptible. The progenies from Masuli/MT4 had the highest leaf and neck blast susceptible reaction, while the most of progenies from IPB (Irradiated Pusa Basmati), KalinghaIII_IR64, Radha 32_ KIII and Masuli_IR64 were resistant, and the most promising sources against leaf and neck blast resistance. Therefore, the progenies from these parents can be used in breeding the resistant variety. Key words: Pyricularia grisea, resistance, rice lines J. Inst. Agric. Anim. Sci. 27:37-44 (2006)

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Brondani, Claudio, Rosana Pereira Vianello Brondani, Lucas da Ressurreição Garrido y Márcio Elias Ferreira. "Development of microsatellite markers for the genetic analysis of Magnaporthe grisea". Genetics and Molecular Biology 23, n.º 4 (diciembre de 2000): 753–62. http://dx.doi.org/10.1590/s1415-47572000000400009.

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An AG microsatellite-enriched genomic DNA library was constructed for Magnaporthe grisea (anamorph Pyricularia grisea), the causal agent of rice blast. Seventy-two DNA clones containing microsatellite repeats were isolated and sequenced in order to develop a series of new PCR-based molecular markers to be used in genetic studies of the fungus. Twenty-four of these clones were selected to design primer pairs for the PCR amplification of microsatellite alleles. Single spore cultures of M. grisea isolated from rice and wheat in Brazil, Colombia and China were genotyped at three microsatellite loci. Isolates from southern Brazil were predominantly monomorphic at the tested SSR loci, indicating a low level of genetic variability in these samples. However, seven alleles were observed at the MGM-1 locus in isolates from Central Brazil and at least nine alleles were detected at the same locus in a sample of Colombian isolates. Polymorphism analysis at SSR loci is a simple and direct approach for estimating the genetic diversity of M. grisea isolates and a powerful tool for studying M. grisea genetics.

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Antonio, Rafaela Priscila, Pedro Martins Ribeiro Júnior, Irlane Cristine de Souza Andrade Lira, Lucas Peixinho Campos Nery, Jullie Cryscelle Leandro Silva, Bruno Djvan Ramos Barbosa y Breno dos Santos Costa. "Reação de acessos de Cenchrus a Pyricularia grisea no semiárido brasileiro". Journal of Environmental Analysis and Progress 6, n.º 4 (9 de diciembre de 2021): 396–402. http://dx.doi.org/10.24221/jeap.6.4.2021.4689.396-402.

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O fungo Pyricularia grisea causa manchas foliares em capim buffel (Cenchrus ciliaris), sendo um problema em pastagens dessa forragem no Texas, EUA e México. Apesar desta doença não apresentar problemas graves ao capim buffel no Semiárido brasileiro, a busca de germoplasma com algum nível de tolerância a esta doença tem importância preventiva. O objetivo neste estudo foi avaliar a reação de acessos de Cenchrus spp. a P. grisea, em infecção natural. Foram avaliados 20 acessos pertencentes ao Banco Ativo de Germoplasma (BAG) de Cenchrus da Embrapa Semiárido, em blocos casualizados com três repetições e parcela contento 20 plantas. As avaliações foram realizadas em dois ciclos de avaliação em 2019 e 2020, no período chuvoso, quando as condições ambientais para o desenvolvimento da doença eram favoráveis. Para a avaliação da severidade da doença foi utilizada uma escala de notas variando de 1 a 4 e percentual da área foliar lesionada. Os dados médios das notas por parcelas foram submetidos a análise de variância e as médias comparadas pelo teste de Scott e Knott, à 5% de significância. Houve efeito significativo para a tolerância à doença. Dez acessos receberam nota média acima de 3 (CPATSA 83476; CPATSA 79151; CPATSA 79150; CPATSA 79591; CPATSA 90194; CPATSA 79144; CPATSA 79558; CPATSA 79134; CPATSA 90570; CPATSA 79613), nas duas avaliações, indicando uma moderada resistência em relação a testemunha suscetível, a cultivar Biloela. Existe variabilidade a ser explorada para reação a P. grisea no BAG de Cenchrus da Embrapa Semiárido.

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23

Harmon, P., K. Rane, G. Ruhl y R. Latin. "First Report of Gray Leaf Spot on Perennial Ryegrass in Indiana". Plant Health Progress 1, n.º 1 (enero de 2000): 27. http://dx.doi.org/10.1094/php-2000-0607-01-hn.

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Pyricularia grisea, the causal agent of gray leaf spot on turfgrass, was isolated from symptomatic perennial ryegrass (Lolium perenne) leaves collected from a golf course in north-central Indiana in August 1999. Gray leaf spot is an emerging threat to stands of perennial ryegrass in the mid-Atlantic and Midwestern United States. Posted 7 June 2000.

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24

Tsukiboshi, T., I. Okabe y K. Sugawara. "First Report of Blast of Guinea Grass Caused by Pyricularia sp. LS-Group in Japan". Plant Disease 93, n.º 12 (diciembre de 2009): 1350. http://dx.doi.org/10.1094/pdis-93-12-1350c.

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Guinea grass (Panicum maximum Jacq.) is an important C-4 perennial herbage in the southern part of Japan. In February 2002, a blast disease was found on the grass cultivated on the Okinawa Islands, the southern most region of Japan. Early symptoms appeared as small, round or ellipsoid lesions on leaves. Lesions later expanded to 2 to 5 × 1 to 2 mm and were spindle shaped and grayish white in the central area with dark brown margins. We obtained three single-conidia isolates of a Pyricularia-like fungus from the lesions and deposited them in the NIAS Genebank, Japan as MAFF306662, 306671, and 306672. The isolates were grown under near-UV light on V8 juice agar for 7 days to produce conidia, and guinea grass plants of the seven- to eight-leaf stage grown from seeds in a green house, five plants for each isolate, were inoculated by atomizing them with the conidial suspension of 105 conidia/ml. The same number of plants sprayed with sterilized distilled water served as the control. The experiments were repeated twice. All plants were covered with plastic bags for 24 h at 25°C to maintain high relative humidity. After 7 days, all inoculated plants showed symptoms identical to those observed in the field. Controls remained symptom free. The Pyricularia-like fungus was reisolated from lesions on inoculated leaves. The morphologies of the isolates were observed and described from the colonies grown under the condition described above. Conidiophores were pale brown, emerging singly or in small groups, straight or flexuous, geniculate toward the apex, and 36 to 197 × 2 to 5 μm. Conidia were obpyriform, straight, colorless to pale brown, smooth, and 19 to 30 × 5 to 10 μm with two to three septa. The morphologies were the same as those of the description of the genus Pyricularia. Previously, all Pyricularia isolates from Gramineae had been identified as P. grisea, except for those from rice (3,4). However, a new taxonomy of Pyricularia spp. based on DNA analyses was proposed by Couch and Kohn (1). Only the isolates from Digitaria were classified as P. grisea and those from C-3 grasses classified as P. oryzae. However, the species names for the isolates from the other C-4 grasses were not described. We analyzed the sequences of the rDNA-ITS region (ITS1-5.8s-ITS2) and β-tubulin gene of the isolates from guinea grass following Couch and Kohn (1). The sequences of rDNA-ITS (GenBank Accession No. AB512785) and β-tubulin (AB512786) of the isolate MAFF306672 matched the sequences of those of the Pyricularia sp. LS-group (AB274426 and AB274458, respectively) isolated from Leersia oryzoides. Hirata et al. (2) reclassified Pyricularia isolates from Gramineae by multilocus phylogenetic analysis and showed that non-P. oryzae and non-P. grisea isolates could be classified into two groups of the Pyricularia sp., a LS- and a CE-group, corresponding to those isolated from Leersia spp. and Setaria spp. or Cenchrus spp. of grasses, respectively. Since no Magnaporthe teleomorph was produced by the crossing tests using the isolates, we identified the isolates from guinea grass as the Pyricularia sp. LS-group on the basis of their morphology and the molecular phylogenetic analysis. To our knowledge, this is the first report of blast on guinea grass in Japan. References: (1) B. C. Couch and L. M. Kohn. Mycologia 94:683, 2002. (2) K. Hirata et al. Mycol. Res. 111:799, 2007. (3) K. D. Hyde. Australas. Plant Pathol. 22:73, 1993. (4) R. Sprague. Diseases of Cereals and Grasses in North America. Ronald Press Company, New York, 1950.

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Sanmathi Kumar, R. P., L. Shanthala, T. B. Anilkumar y Sudharshana L. "Phytotoxins from Pyricularia grisea and Their Effect on Finger Millet". Journal of Plant Biochemistry and Biotechnology 15, n.º 1 (enero de 2006): 63–66. http://dx.doi.org/10.1007/bf03321905.

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Xia, Jun Q., Fleet N. Lee, Kyung S. Kim y Frederick W. Spiegel. "Characterization of Monoclonal Antibodies to Conidial Antigens of Pyricularia grisea". Experimental Mycology 17, n.º 3 (septiembre de 1993): 170–81. http://dx.doi.org/10.1006/emyc.1993.1016.

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27

Qi, Hexing, Jun Yang, Changfa Yin, Jian Zhao, Xianxian Ren, Shishuang Jia y Guozhen Zhang. "Analysis of Pyricularia oryzae and P. grisea from Different Hosts Based on Multilocus Phylogeny and Pathogenicity Associated with Host Preference in China". Phytopathology® 109, n.º 8 (agosto de 2019): 1433–40. http://dx.doi.org/10.1094/phyto-10-18-0383-r.

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Pyricularia oryzae and P. grisea are important agents of major diseases on a wide range of gramineous hosts. Whereas P. oryzae is the most important pathogen causing outbreaks of rice blast, P. grisea is mainly a pathogen of crabgrass. In this study, 103 P. oryzae and 20 P. grisea isolates were collected from seven species of plants, and we analyzed their phylogeny, pathogenicity, and relationship with host preferences to investigate the differences among them from different hosts. Based on phylogenetic analysis of multilocus sequences, 16 isolates from crabgrass and four isolates from green bristlegrass were identified as P. grisea and another 103 isolates from crabgrass, green bristlegrass, goose grass, foxtail millet, wild millet, rice, and sedge belonged to P. oryzae. Results of pathogenicity tests by artificial inoculation demonstrated that six of 10 P. oryzae isolates from rice and three of 44 P. oryzae isolates from green bristlegrass showed cross-infectivity on green bristlegrass and rice, respectively. Taken together, our results demonstrated that isolates from green bristlegrass and crabgrass consist of both P. oryzae and P. grisea and that P. oryzae isolates showed cross-infectivity between rice and green bristlegrass, suggesting that host shifts may occur for P. oryzae and P. grisea.

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Babu, Talluri Kiran, Rajan Sharma, R. P. Thakur, Hari D. Upadhyaya, P. Narayan Reddy y A. G. Girish. "Selection of Host Differentials for Elucidating Pathogenic Variation in Magnaporthe grisea Populations Adapted to Finger Millet (Eleusine coracana)". Plant Disease 99, n.º 12 (diciembre de 2015): 1784–89. http://dx.doi.org/10.1094/pdis-10-14-1089-re.

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Blast, caused by Pyricularia grisea (teleomorph: Magnaporthe grisea), is the most devastating disease of finger millet affecting production, utilization, and trade in Africa and Southeast Asia. An attempt was made to select a set of putative host differentials that can be used to determine virulence diversity in finger-millet-infecting populations of M. grisea. Thus, a differential set comprising eight germplasm accessions selected from finger millet core collection (IE 2911, IE 2957, IE 3392, IE 4497, IE 5091, IE 6240, IE 6337, and IE 7079) and a resistant (‘GPU 28’) and a susceptible (‘VR 708’) variety was developed. This differential set was used to study pathogenic variation in 25 isolates of M. grisea collected from Karnataka, Telangana, and Andhra Pradesh states in India. Based on the reaction (virulent = score ≥4 and avirulent = score ≤3 on a 1-to-9 scale) on host differentials, nine pathotypes were identified among 25 M. grisea isolates. Pathotype 9, represented by isolate Pg23 from Vizianagaram, was the most virulent because it could infect all of the host differentials except GPU 28. This study will be helpful in devising strategies for monitoring virulence change in M. grisea populations, and for identification of blast resistance in finger millet for use in disease resistance breeding programs.

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Jo, Young-Ki, Guo-Liang Wang y Michael J. Boehm. "Expression Analysis of Rice Defense-Related Genes in Turfgrass in Response to Magnaporthe grisea". Phytopathology® 97, n.º 2 (febrero de 2007): 170–78. http://dx.doi.org/10.1094/phyto-97-2-0170.

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Magnaporthe grisea (anamorph = Pyricularia grisea) causes blast on rice (Oryza sativa) and gray leaf spot on turfgrass. Gray leaf spot is a serious disease on St. Augustinegrass (Stenotaphrum secundatum), perennial ryegrass (Lolium perenne), and tall fescue (Festuca arundinacea). Virulence assays performed in this study revealed that M. grisea collected from rice could also cause disease on St. Augustinegrass and tall fescue. One rice isolate, Che86061, caused similar disease reactions on susceptible cultivars of rice and St. Augustinegrass and an incompatible interaction on resistant cultivars of both species. To explore whether similar defense-related genes are expressed in rice and St. Augustinegrass, a rice cDNA library was screened using pooled cDNAs derived from M. grisea-infected St. Augustinegrass. Thirty rice EST (expressed sequence tag) clones showing differential expression in St. Augustinegrass following M. grisea inoculation were identified and classified into six putative functional groups. Northern blot analyses of seven EST clones that collectively represented each putative functional group confirmed that the expression of five out of seven EST clones was similar in both rice and St. Augustinegrass. This study represents one of the first attempts to use a broad-scale genomic approach and resources of a model monocot system to study defense gene expression in St. Augustinegrass following M. grisea infection.

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Nakayashiki, Hitoshi, Kanako Kiyotomi, Yukio Tosa y Shigeyuki Mayama. "Transposition of the Retrotransposon MAGGY in Heterologous Species of Filamentous Fungi". Genetics 153, n.º 2 (1 de octubre de 1999): 693–703. http://dx.doi.org/10.1093/genetics/153.2.693.

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Abstract MAGGY is a gypsy-like LTR retrotransposon isolated from the blast fungus Pyricularia grisea (teleomorph, Magnaporthe grisea). We examined transposition of MAGGY in three P. grisea isolates (wheat, finger millet, and crabgrass pathogen), which did not originally possess a MAGGY element, and in two heterologous species of filamentous fungi, Colletotrichum lagenarium and P. zingiberi. Genomic Southern analysis of MAGGY transformants suggested that transposition of MAGGY occurred in all filamentous fungi tested. In contrast, no transposition was observed in any transformants with a modified MAGGY containing a 513-bp deletion in the reverse transcriptase domain. When a MAGGY derivative carrying an artificial intron was introduced into the wheat isolate of P. grisea and C. lagenarium, loss of the intron was observed. These results showed that MAGGY can undergo autonomous RNA-mediated transposition in heterologous filamentous fungi. The frequency of transposition differed among fungal species. MAGGY transposed actively in the wheat isolate of P. grisea and P. zingiberi, but transposition in C. lagenarium appeared to be rare. This is the first report that demonstrates active transposition of a fungal transposable element in heterologous hosts. Possible usage of MAGGY as a genetic tagging tool in filamentous fungi is discussed.

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Perini, Vilma Borges de Moura, Henrique Guilhon de Castro, Gil Rodrigues dos Santos, Alo´´isio Freitas Chagas Junior, Dione Pereira Cardoso, Raimundo Wagner de Sousa Aguiar y Adriano de Aguiar Soares. "Efeito de extratos vegetais na inibição do crescimento micelial de Pyricularia grisea". Journal of Biotechnology and Biodiversity 4, n.º 1 (7 de enero de 2013): 70–77. http://dx.doi.org/10.20873/jbb.uft.cemaf.v4n1.perini.

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O objetivo deste estudo foi avaliar o efeito do óleo extraído de quatro espécies e de diferentes tipos de extratos de capim-citronela na inibição do crescimento micelial dos fungos Pyricularia grisea. Foram avaliadas a fungitoxicidade do óleo essencial de capim-citronela (Cymbopogon nardus), eucalipto (Eucalyptus citriodora), copaíba (Copaifera officinalis) e buriti (Mauritia flexuosa). O óleo comercial de opaiba e buriti foi adquirido nos mercados livres de Gurupi-TO e o óleo essencial de capim-citronela e eucalipto foi extraído por destilação a vapor. Em outro experimento, cinco tipos de extratos de capim-citronela foram utilizados: maceração, infusão, decocção, óleo essencial e hidrolato. O uso de óleo essencial de capim-citronela proporcionou maior potencial de inibição do crescimento micelial de P. grisea (CE50 = 0,191 ppm) quando comparado aos demais óleos avaliados e aos demais tipos de extratos de capim-citronela.

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Greer, C. A. y R. K. Webster. "Occurrence, Distribution, Epidemiology, Cultivar Reaction, and Management of Rice Blast Disease in California". Plant Disease 85, n.º 10 (octubre de 2001): 1096–102. http://dx.doi.org/10.1094/pdis.2001.85.10.1096.

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Rice blast, caused by Pyricularia grisea, was first found in California in 1996. Disease surveys have shown the blast disease is spreading at a moderate rate in California rice fields. Although no effective major resistance genes are known to occur in widely grown commercial California cultivars, there appear to be differences among the cultivars with respect to field susceptibility to the pathogen. P. grisea was recovered from rice crop residue and commercial seedlots which are suggested as possible sources of initial P. grisea inoculum in California rice fields. Examination of weather data indicates that environmental conditions in California rice-producing areas are permissive for rice blast but generally not optimal for epidemic development. Spore trapping determined that the majority of P. grisea conidia are generally not released until approximately 6:00 A.M. and would not have sufficient time for infection before leaf wetness periods end. Azoxystrobin showed positive results with respect to reduction of neck blast incidence and yield increases in small-plot and large-scale fungicide trials.

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Cardoso, Cinara Araújo de Andrade, Erlei Melo Reis y Eder Novaes Moreira. "Development of a warning system for wheat blast caused by Pyricularia grisea". Summa Phytopathologica 34, n.º 3 (septiembre de 2008): 216–21. http://dx.doi.org/10.1590/s0100-54052008000300002.

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Wheat (Triticum aestivum L.) blast caused by Pyricularia grisea is a new disease in Brazil and no resistant cultivars are available. The interactions between temperature and wetness durations have been used in many early warning systems. Hence, growth chamber experiments to assess the effect of different temperatures (10, 15, 20, 25, 30 and 35ºC) and the duration of spike-wetness (0, 5, 10, 15, 20, 25, 30, 35 and 40 hours) on the intensity of blast in cultivar BR23 were carried out. Each temperature formed an experiment and the duration of wetness the treatments. The highest blast intensity was observed at 30°C and increased as the duration of the wetting period increased while the lowest occurred at 25°C and 10 hours of spike wetness. Regardless of the temperature, no symptoms occurred when the wetting period was less than 10 hours but at 25°C and a 40 h wetting period blast intensity exceeded 85%. These variations in blast intensity as a function of temperature are explained by a generalized beta model and as a function of the duration of spike wetness by the Gompertz model. Disease intensity was modeled as a function of both temperature and the durations of spike wetness and the resulting equation provided a precise description of the response of P. grisea to temperatures and the durations of spike wetness. This model was used to construct tables that can be used to predict the intensity of P. grisea wheat blast based on the temperatures and the durations of wheat spike wetness obtained in the field.

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Maciel, João L. N., Paula C. S. Rodrigues, Oneides A. Avozani y Marcelo G. Moraes. "Padrão molecular e de virulência de isolados de Pyricularia grisea do Estado do Rio Grande do Sul". Fitopatologia Brasileira 29, n.º 5 (octubre de 2004): 504–10. http://dx.doi.org/10.1590/s0100-41582004000500006.

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A obtenção de genótipos resistentes à brusone é uma das maiores dificuldades para os programas de melhoramento genético de arroz (Oryza sativa) devido à variabilidade do fungo Pyricularia grisea. Esta diversidade do fungo tem sido caracterizada por meio de marcadores moleculares de DNA e pela virulência de isolados do patógeno demonstrada em genótipos de arroz com diferentes genes de resistência à brusone. Os marcadores moleculares permitem identificar isolados de P. grisea em grupos geneticamente relacionados denominados de linhagens e as linhas isogênicas em grupos com padrões de virulência iguais ou muito similares. Assim, este trabalho foi realizado com os objetivos de verificar os padrões moleculares e de virulência de isolados de P. grisea do Rio Grande do Sul. O DNA de 51 isolados monospóricos de P. grisea obtidos do Rio Grande do Sul foi utilizado em reações de PCR com os oligonucleotídeos iniciadores baseados na seqüência repetitiva Pot2. Os mesmos isolados também foram utilizados para inocular plantas de seis linhas isogênicas de arroz. A análise estatística indicou a ocorrência de seis linhagens e sete grupos de virulência. A ocorrência de isolados que causam reações de compatibilidade em linhas isogênicas que contêm o alelo Pi-1 foi maior do que aquelas que possuem o alelo Pi-2. As reações de compatibilidade na linha isogênica C 101 A51 caracterizaram-se pela baixa severidade, em geral, avaliadas como sendo de nota 4. Não foi verificada uma relação direta entre os padrões moleculares e de virulência dos isolados avaliados.

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Guerber, C. y D. O. TeBeest. "Infection of Rice Seed Grown in Arkansas by Pyricularia grisea and Transmission to Seedlings in the Field". Plant Disease 90, n.º 2 (febrero de 2006): 170–76. http://dx.doi.org/10.1094/pd-90-0170.

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Rice blast, caused by Pyricularia grisea, is an important and serious disease of rice (Oryza sativa) in the southeastern United States. The disease sporadically reaches epidemic proportions on susceptible cultivars within fields and over large areas within Arkansas. The main overwintering sources of inoculum reportedly include infected rice stubble, related host species, and infected seed. The objectives of the research were to (i) determine whether rice seed grown in Arkansas were infected with P. grisea, (ii) investigate the relationship between seed infection and seedling disease, and (iii) determine if planting naturally infected seed could lead to the subsequent development of rice blast on seedlings in the field. The results of seed assays showed that P. grisea was detected in samples of foundation, certified, and production seed. Estimated levels of infection by P. grisea of rice seed from 66 samples of rice seed grown in Arkansas ranged from 0 to 10.5%. Planting infected seed in the greenhouse and the field resulted in seedling infection. Planting naturally infected seed may result in disease development (i) from seedlings grown from infected seed planted beneath the soil surface, (ii) from seedlings grown from germinating seed left on the soil surface, (iii) from seed coats, or (iv) from nongerminated seed left on the soil surface after planting. Additional research is necessary to establish the mechanisms of infection of seedlings and to establish disease thresholds for this important fungal pathogen of rice.

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PRABHU, ANNE S., MARTA C. FILIPPI y LEILA G. ARAUJO. "Pathotype diversity of Pyricularia grisea from improved upland rice cultivars in experimental plots". Fitopatologia Brasileira 27, n.º 5 (septiembre de 2002): 468–73. http://dx.doi.org/10.1590/s0100-41582002000500005.

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A study was undertaken to examine the pathogenic diversity of Pyricularia grisea isolates retrieved from 14 upland rice (Oryza sativa) cultivars in experimental plots during a period of five years. Inoculations were performed on 32 genotypes with 85 monoconidial isolates under controlled greenhouse conditions. Based on the reaction pattern of eight international differentials, eleven pathotypes of P. grisea were identified. The predominant international races or pathotypes were IB-9 (56.4%), IB-1 (16.4%) and IB-41 (11.8%). A set of eight commercial upland rice cultivars ('Carajás', 'Confiança', 'Maravilha', 'Primavera', 'Progresso', 'Caiapó', 'IAC-47', 'IAC-201') was utilized as additional differentials for describing the virulence pattern of P. grisea. Twenty-six Brazilian pathotypes were identified on the basis of disease reaction on these differentials, in contrast to the 11 international pathotypes. The most predominant Brazilian pathotypes, BB-21 and BB-41 were represented by 28.2% and 17.6% of the isolates tested, respectively. Isolates virulent and avirulent to cultivar 'Primavera' were encountered within the pathotype IB-1. Utilizing Brazilian cultivars as differentials, the 14 isolates of the pathotype IB-1could be further classified into eight local pathotypes, BB-41, BB-13, BB-21, BB-9, BB-29, BB-61, BD-9 and BG-1. Virulence to improved rice cultivars 'Canastra', 'Confiança', 'Carisma', 'Maravilha', 'Primavera' and 'Bonança' was frequent in pathogen population. Some of the Brazilian pathotypes that showed differential reaction on commercial rice cultivars could be utilized for incorporating resistance genes in susceptible cultivars improved for grain quality, by conventional breeding methods.

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Gupta, Devendra K. y A. K. Jain. "Slow blasting resistance in Finger millet cultivars to Pyricularia grisea Sacc". Annals of Plant Protection Sciences 28, n.º 2 (2020): 155. http://dx.doi.org/10.5958/0974-0163.2020.00041.5.

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Rossman, Amy Y., Richard J. Howard y Barbara Valent. "Pyricularia grisea, the Correct Name for the Rice Blast Disease Fungus". Mycologia 82, n.º 4 (julio de 1990): 509. http://dx.doi.org/10.2307/3760024.

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39

Varaprasada Rao, Ch y P. Anil Kumar. "Integrated Disease Management of Rice Blast Caused by Pyricularia grisea (Sacc.)". International Journal of Current Microbiology and Applied Sciences 7, n.º 03 (10 de marzo de 2018): 2952–58. http://dx.doi.org/10.20546/ijcmas.2018.703.341.

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EL-WAHSH, SALAH M., RAMADAN A. ARAFA, AMRO R. EMERAN y ELSAYED F. MASHAAL. "VEGETATIVE COMPATIBILITY GROUPS OF PHYSIOLOGICAL RACES OF PYRICULARIA GRISEA IN Egypt". Egyptian Journal of Agricultural Research 91, n.º 4 (1 de diciembre de 2013): 1245–58. http://dx.doi.org/10.21608/ejar.2015.165077.

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Cruz, Maria Fernanda A., João L. N. Maciel, Ariano M. Prestes, Estevon A. S. Bombonatto, Jorge F. Pereira y Luciano Consoli. "Caracterização genética e fenotípica de isolados de Pyricularia grisea do trigo". Tropical Plant Pathology 34, n.º 6 (diciembre de 2009): 393–401. http://dx.doi.org/10.1590/s1982-56762009000600005.

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42

Malavolta, Vanda Maria Angeli, Aline de Paula Carqueijo y Lívia Mendes. "Variabilidade patogênica do fungo Pyricularia grisea no Estado de São Paulo". Summa Phytopathologica 35, n.º 1 (febrero de 2009): 49–52. http://dx.doi.org/10.1590/s0100-54052009000100008.

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Amostras de arroz com sintomas de brusone foram coletadas no período 2004-06 em diferentes regiões produtoras do Estado de São Paulo. Foram obtidos 71 isolados monospóricos do fungo P. grisea, e para a caracterização da variabilidade patogênica desses isolados foram utilizadas as séries diferenciadoras internacional e japonesa. Segundo a série internacional, os 71 isolados foram agrupados em 21 patótipos. Predominaram raças dos grupos IB, ID e IG, com 23, 21 e 17 constatações respectivamente. A variedade Raminad Str.3 apresentou os genes de resistência mais efetivos, não suplantados por nenhum dos isolados testados, seguida da NP 125 (5,6% de reações suscetíveis) e Dular (11,3 %). Por outro lado, a resistência da variedade Sha-tiao-tsao foi suplantada pela maioria dos isolados (90,1 % de reações suscetíveis), seguida da Usen (62,0%) e da Caloro (53,5 %). Pela série japonesa, os isolados foram agrupados em 36 patótipos, e a análise do espectro de virulência dos isolados mostra que nenhum dos isolados teve a capacidade de suplantar a resistência conferida pelo gene pi-ta² e somente 1 isolado a do gene pi-z t . Por outro lado, 63,4 % dos isolados conseguiram causar sintomas em plantas com o gene pi-a, 59,1% com o gene pi-ta e 53,5 % com o gene pi-i.

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Verzignassi, Jaqueline Rosemeire, Luiz Sebastião Poltronieri, Ruth Linda Benchimol, Sueny Kelly Santos de França, Eudes de Arruda Carvalho y Celso Dornelas Fernandes. "Pyricularia grisea: novo patógeno em Brachiaria brizantha cv. Marandu no Pará". Summa Phytopathologica 38, n.º 3 (septiembre de 2012): 254. http://dx.doi.org/10.1590/s0100-54052012000300016.

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Rossman, Amy Y., Richard J. Howard y Barbara Valent. "Pyricularia Grisea the Correct Name for the Rice Blast Disease Fungus". Mycologia 82, n.º 4 (julio de 1990): 509–12. http://dx.doi.org/10.1080/00275514.1990.12025916.

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Camargo, Meyriele Pires de, Maria Heloisa Duarte de Moraes y José Otávio Machado Menten. "Efficiency of Blotter test and agar culture medium to detect Fusarium graminearum and Pyricularia grisea in wheat seeds". Journal of Seed Science 39, n.º 3 (septiembre de 2017): 297–302. http://dx.doi.org/10.1590/2317-1545v39n3168931.

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Abstract: Seeds can be considered one of the most efficient forms to disseminate pathogens. Therefore, the use of healthy seeds is extremely important to establish a crop, and seed health testing must be performed to determine the seed sanitary quality. This study aimed to compare the efficiency of seed health testing to detect Pyricularia grisea and Fusarium graminearum in three samples of wheat seeds. Methods evaluated were Blotter test with freezing (BTF) and potato-dextrose-agar culture medium (PDA). The incubation temperatures were 20 ºC and 25 ºC. From each sample, a subsample was submitted to seed asepsis using hypochlorite solution (1%) and another analyzed without seed asepsis. The temperatures evaluated did not influence the detection of the pathogens. P. grisea incidence ranged from 4.5 to 17% with BTF without seed asepsis. The BTF with seed asepsis and PDA (with and without seed asepsis) presented pathogen incidence no higher than 1.5%. Moreover, results suggested that most part of P. grisea inoculum was presented externally on seed tissues. PDA medium was more efficient to detect F. graminearum, independently of seed asepsis. By this method, pathogen incidence ranged from 3 to 39%. F. graminearum incidence using BTF with seed asepsis varied from 0.5 to 1.5% and BTF without seed asepsis presented a pathogen incidence of 5.0 to 12.5%. The Blotter test with freezing was more efficient to detect P. grisea while the PDA medium was more efficient to detect F. graminearum.

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46

Pedersen, D. K., R. T. Kane y H. T. Wilkinson. "First Report of Gray Leaf Spot Caused by Pyricularia grisea on Lolium perenne in Illinois". Plant Disease 84, n.º 10 (octubre de 2000): 1151. http://dx.doi.org/10.1094/pdis.2000.84.10.1151b.

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Each year from 1991 to 1999, a disease matching the description of gray leaf spot (1) was observed in the central and north central regions of Illinois. Disease severity was low (<10% blight) from 1991 to 1994 and 1999 and was severe (>50% blight in some areas) from 1995 to 1998. The disease was observed on Lolium perenne (perennial ryegrass) golf course fairways and sports fields. Isolations of Pyricularia grisea were made from L. perenne collected from golf courses in Bloomington, Decatur, Kankakee, Pekin, Urbana, and Moline, IL. All isolates were collected from surface-sterilized, symptomatic leaves. Cultures were maintained on one-fifth strength potato-dextrose agar (PDA) and induced to sporulate on full-strength oatmeal agar. All isolates in culture displayed vegetative and conidial characteristics similar to those previously described for P. grisea (1). Twenty-five different L. perenne germ plasms were inoculated with isolate WF9826 (Kankakee) using a suspension of 1 × 105 conidia per milliliter. The 4-week-old lawns (100 plants per 3-cm-diameter cone-tainer) of each ryegrass germ plasm were inoculated by spraying foliage with the conidial suspension until runoff. Inoculated and uninoculated lawns were enclosed in plastic bags and placed in an incubator (16 h light; 28°C) for 7 days. Disease severity was rated using a scale of 0 to 10 (10 = 100% blight). Each treatment was replicated three times, and all experiments were repeated four times. Small blue-gray, water-soaked lesions with dark brown borders were observed on leaves of all inoculated ryegrass germ plasms. Advanced symptoms included blighting of much of the leaves. The mean disease severity rating was 3.8 (range 2 to 7) for all experimental units and all 25 germ plasms. P. grisea was isolated from leaves that were inoculated with WF9826. This is the first report of gray leaf spot of perennial ryegrass caused by P. grisea in Illinois. Reference: (1) P. J. Landschoot et al. Plant Dis. 76:1280, 1992.

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Viji, G., B. Wu, S. Kang, W. Uddin y D. R. Huff. "Pyricularia grisea Causing Gray Leaf Spot of Perennial Ryegrass Turf: Population Structure and Host Specificity". Plant Disease 85, n.º 8 (agosto de 2001): 817–26. http://dx.doi.org/10.1094/pdis.2001.85.8.817.

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Gray leaf spot is a serious disease of perennial ryegrass (Lolium perenne) turf in the United States. Isolates of Pyricularia grisea causing the disease in perennial ryegrass were characterized using molecular markers and pathogenicity assays on various gramineous hosts. Genetic relationships among perennial ryegrass isolates were determined using different types of trans-posons as probes. Phylogenetic analysis using Pot2 and MGR586 probes, analyzed with AMOVA (analysis of molecular variance), showed that these isolates from perennial ryegrass consist of three closely related lineages. All the isolates belonged to a single mating type, MAT1-2. Among 20 isolates from 16 host species other than perennial ryegrass, only the isolates from wheat (Triticum aestivum) and triticale (× Triticosecale), showed notable similarity to the perennial ryegrass isolates based on their Pot2 fingerprints. The copy number and fingerprints of Pot2 and MGR586 in isolates of P. grisea from perennial ryegrass indicate that they are genetically distinct from the isolates derived from rice (Oryza sativa) in the United States. The perennial ryegrass isolates also had the same sequence in the internal transcribed spacer (ITS) region of the genes encoding ribosomal RNA as that of the wheat and triticale isolates, and exhibited rice isolate sequence polymorphisms. In pathogenicity assays, all the isolates of P. grisea from Legacy II perennial ryegrass caused characteristic blast symptoms on Marilee soft white winter wheat, Bennett hard red winter wheat, Era soft white spring wheat, and Presto triticale, and they were highly virulent on these hosts. An isolate from wheat and one from triticale (from Brazil) were also highly virulent on perennial ryegrass and Rebel III tall fescue (Festuca arundinacea). None of the isolates from perennial ryegrass caused the disease on Lagrue rice, and vice versa. Understanding the population structure of P. grisea isolates infecting perennial ryegrass and their relatedness to isolates from other gramineous hosts may aid in identifying alternate hosts for this pathogen.

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Filippi, Marta Cristina, Anne Sitarama Prabhu, Leila Garcês de Araújo y Josias Correa de Faria. "Genetic diversity and virulence pattern in field populations of Pyricularia grisea from rice cultivar Metica-1". Pesquisa Agropecuária Brasileira 37, n.º 12 (diciembre de 2002): 1681–88. http://dx.doi.org/10.1590/s0100-204x2002001200002.

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Rice blast is a major yield constraint of the irrigated rice in the State of Tocantins, Brazil. The objective of this investigation was to study the phenotypic and genetic diversity within the pathogen population of Pyricularia grisea in samples collected from four individual farms of rice cultivar Metica-1, under epidemic conditions of leaf blast. A set of 87 isolates was tested on 32 rice genotypes including eight international differentials. Considering 80% similarity in virulence, two groups comprising a total of 81 isolates were recognized, independently of the farms from which they were collected. Eighty percent of the isolates pertained to pathotype ID-14, indicating high cultivar specificity and narrow diversity of virulence in the sample population. The virulence in pathogen population on rice cultivars BR-IRGA 409 and Rio Formoso was low. Analysis of P. grisea isolates using rep-PCR with two primer sequences from Pot2 generated fingerprint profiles of one to nine bands. Cluster analysis revealed the occurrence of six fingerprint groups with similarities ranging from 0.09 to 1. There was no straight relationship between virulence of the isolates based on reaction pattern on 32 genotypes and grouping based on Pot2 rep-PCR analysis of P. grisea isolates collected from 'Metica-1'.

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Silva, Gisele B. da y Anne S. Prabhu. "Quantificação de conídios de Pyricularia grisea no plantio direto e convencional de arroz de terras altas". Fitopatologia Brasileira 30, n.º 6 (diciembre de 2005): 569–73. http://dx.doi.org/10.1590/s0100-41582005000600001.

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Foi estudada a liberação de conídios de Pyricularia grisea no plantio convencional (PC) e direto (PD) de arroz (Oryza sativa) de terras altas, nas fases de desenvolvimento vegetativo e emissão de panículas nos experimentos de campo realizados em dois anos (1998/2000). As coletas de conídios de P. grisea foram realizadas com as armadilhas volumétricas Rotorod sampler. Objetivando quantificar os conídios viáveis e com potencial para causar infecção em folhas novas foram também utilizadas bandejas com plantas de arroz com 25 dias de idade das cultivares Carajás e Primavera expostas no campo, como armadilhas vivas. Na safra 1998/1999, o número de conídios de P. grisea aumentou linearmente com o tempo, entre o estádio de grão pastoso e maduro. Na safra de 1999/2000, a quantidade de conídios coletada aumentou de maneira exponencial, iniciando ao final do estádio emborrachamento até na fase de grão semi-maduro. O número de conídios coletados com a armadilha volumétrica diminuiu exponencialmente com o aumento da precipitação pluviométrica, assim como, reduziu a severidade da brusone nas plantas da armadilha viva tanto para a cultivar Carajás como para Primavera. A produção e a liberação de conídios foi menor no plantio direto tanto na fase vegetativa como durante o enchimento dos grãos nas panículas.

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Vincelli, P. y E. Dixon. "Resistance to QoI (Strobilurin-like) Fungicides in Isolates of Pyricularia grisea from Perennial Ryegrass". Plant Disease 86, n.º 3 (marzo de 2002): 235–40. http://dx.doi.org/10.1094/pdis.2002.86.3.235.

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In August 2000, azoxystrobin was ineffective in controlling gray leaf spot of perennial ryegrass at a golf course in Lexington, KY and at two golf courses in Illinois. Isolates suspected of being fungicide-resistant (“suspect isolates”) were compared to “baseline” isolates obtained from sites with no known use of quinol-oxidizing inhibitor (QoI) fungicides. Conidial germination of Pyricularia grisea was tested in vitro with 100 μg of salicylhydroxamic acid per ml. For baseline isolates, 50% effective concentration (EC50) values for azoxystrobin and trifloxystrobin were 0.015 to 0.064 and 0.013 to 0.078 μg/ml, respectively; EC50 values for suspect isolates were 2.39 to 44.8 and 0.31 to 111, respectively. All suspect isolates exhibited significantly (P = 0.05) lower sensitivity to QoI fungicides than all baseline isolates. The mean EC50 values for suspect isolates for azoxystrobin and trifloxystrobin were 690 and 827 times higher, respectively, than the means for baseline isolates. In the laboratory, azoxystrobin and trifloxystrobin provided essentially complete control of disease induced by nine baseline isolates in vivo. Azoxystrobin and trifloxystrobin provided poor to no control of disease induced by six of eight suspect isolates; control of disease induced by the remaining two isolates was partial for azoxystrobin and complete for trifloxystrobin. We conclude that one or more biotypes of perennial ryegrass-infecting strains of P. grisea with resistance to QoI fungicides have emerged. This is the first report of resistance to QoI fungicides in P. grisea. Furthermore, this is one of two QoIresistant fungal pathogens collected in the United States during the 2000 growing season, the first instances reported for North America.

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