Genetic analyses of electrophoretic enzyme variants, mating type, and hermaphroditism in Pyricularia oryzae Cavara

1985 ◽  
Vol 27 (6) ◽  
pp. 697-704 ◽  
Author(s):  
Hei Leung ◽  
Paul H. Williams
Keyword(s):  
Lactate Dehydrogenase ◽  
Mating Type ◽  
Rice Blast ◽  
Magnaporthe Grisea ◽  
Finger Millet ◽  
Single Gene ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
Electrophoretic Variants ◽  
Variant Alleles

Pyricularia oryzae (teleomorph: Magnaporthe grisea) parasitizes a variety of gramineous hosts and causes the rice blast disease worldwide. Through matings among P. oryzae isolates from rice, finger millet, and weeping lovegrass the inheritance of electrophoretic variants of six enzymes, phosphoglucomutase (PGM), phosphoglucose isomerase (PGI), glycerate-2-dehydrogenase (G2DH), malate dehydrogenase-3 (MDH-3), lactate dehydrogenase-1 (LDH-1), and lactate dehydrogenase-3 (LDH-3) was determined. All six variants were under single gene control as determined by tetrad and random spore analysis. However, at Ldh-3 and Mdh-3, there were consistent excesses of variant alleles among ascospore segregants. Preliminary data on the genetic control of hermaphroditism suggested that maleness in two Japanese rice isolates might be due to a single gene mutation. Linkage analyses among the six electrophoretic markers, mating type, and hermaphroditism suggested loose linkage between Pgm and G2dh with a recombination frequencies of 43.0%.Key words: linkage, Magnaporthe grisea, rice blast fungus.

scholarly journals Bacillus Cyclic Lipopeptides Iturin and Fengycin Control Rice Blast Caused by Pyricularia oryzae in Potting and Acid Sulfate Soils by Direct Antagonism and Induced Systemic Resistance

2021 ◽  
Vol 9 (7) ◽  
pp. 1441
Author(s):  
Van Bach Lam ◽  
Thibault Meyer ◽  
Anthony Arguelles Arias ◽  
Marc Ongena ◽  
Feyisara Eyiwumi Oni ◽  
...  
Keyword(s):  
Rice Blast ◽  
Induced Systemic Resistance ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
Systemic Resistance ◽  
Acid Sulfate Soils ◽  
Acid Sulfate ◽  
Wide Range ◽  
Bacillus Spp ◽  
Sulfate Soils

Rice monoculture in acid sulfate soils (ASSs) is affected by a wide range of abiotic and biotic constraints, including rice blast caused by Pyricularia oryzae. To progress towards a more sustainable agriculture, our research aimed to screen the biocontrol potential of indigenous Bacillus spp. against blast disease by triggering induced systemic resistance (ISR) via root application and direct antagonism. Strains belonging to the B. altitudinis and B. velezensis group could protect rice against blast disease by ISR. UPLC–MS and marker gene replacement methods were used to detect cyclic lipopeptide (CLiP) production and construct CLiPs deficient mutants of B. velezensis, respectively. Here we show that the CLiPs fengycin and iturin are both needed to elicit ISR against rice blast in potting soil and ASS conditions. The CLiPs surfactin, iturin and fengycin completely suppressed P. oryzae spore germination resulting in disease severity reduction when co-applied on rice leaves. In vitro microscopic assays revealed that iturin and fengycin inhibited the mycelial growth of the fungus P. oryzae, while surfactin had no effect. The capacity of indigenous Bacillus spp. to reduce rice blast by direct and indirect antagonism in ASS conditions provides an opportunity to explore their usage for rice blast control in the field.

scholarly journals Identificação de progênies de arroz resistentes à brusone no Estado de São Paulo, em 1976/77

Bragantia ◽  
1985 ◽  
Vol 44 (1) ◽  
pp. 311-329
Author(s):  
Jaciro Soave ◽  
Luiz Ernesto Azzini ◽  
Octávio Bento de Almeida Camargo ◽  
Armando Pettinelli Júnior ◽  
Mauro Sakai
Keyword(s):  
Rice Blast ◽  
Sao Paulo ◽  
Pyricularia Oryzae ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
São Paulo

Este trabalho apresenta os resultados das pesquisas realizadas para a avaliação da resistência à brusone (Pyricularia oryzae Cav.) dos principais materiais de sequeiro e irrigado do programa de melhoramento genético do Instituto Agronômico do Estado de São Paulo, e de genótipos exóticos, introduzidos de diversos países, visando à obtenção de cultivares de arroz resistentes àquela limitante doença fúngica. Os testes foram realizados em condições de campo, em canteiros padronizados para reação uniforme a P. oryzae, e a avaliação das plantas foi feita através da observação dos sintomas visuais deixados pela doença, aos quais foram atribuídas notas de 1 a 7, conforme a escala de notas adotadas no "Symposium on the rice blast disease", em 1963. Sessenta e três germoplasmas de arroz de sequeiro e trinta de cultivo irrigado foram testados quanto à resistência à brusone na folha, nas seguintes localidades paulistas: Itararé, Mococa, Pariquera-Açu, Pindamonhangaba, Pindorama e Ribeirão Preto. Foram ainda avaliados 102 genótipos exóticos de arroz visando à detecção de fontes de resistência à brusone nas mesmas localidades, além de Campinas. Somente cinco cultivares de sequeiro, GS-73-164, GS-73-165, GS-73-94, IAC-25 e GS-73-17, e dois cultivares de arroz irrigado, IAC-120 e Pinda F-3-7, embora suscetíveis, apresentaram comportamento satisfatório quanto à brusone. Dos genótipos exóticos testados, vinte e sete foram indicados como fontes de resistência à brusone no Estado de São Paulo.

Variation of leaf angle and incidence of rice blast disease

1982 ◽  
Vol 98 (1) ◽  
pp. 225-227 ◽  
Author(s):  
C. R. Mohanty ◽  
S. Gangopadhyay
Keyword(s):  
Rice Blast ◽  
Pyricularia Oryzae ◽  
Seedling Stage ◽  
Blast Disease ◽  
Brown Spot ◽  
Leaf Angle ◽  
Spot Disease ◽  
Brown Spot Disease ◽  
Helminthosporium Oryzae

Blast, caused by Pyricularia oryzae Cav., one of the major foliar diseases of rice, appears sometimes in a devastating form in the seedling stage. The angles subtended by leaves may affect the establishment of the pathogen. Ono (1965) observed that leaf angles of rice plants, among many other factors, influenced deposition of spores. Gangopadhyay & Chattopadhyay (1974) found that brown spot disease (Helminthosporium oryzae) incidence in rice increased with increase in leaf angles. The present study is intended to find out the role of leaf angles in rice on the incidence of blast disease at the seedling stage.

scholarly journals Cross-Compatibility and Distribution of Mating Type Alleles of the Rice Blast Fungus Magnaporthe grisea in India

Plant Disease ◽  
2000 ◽  
Vol 84 (6) ◽  
pp. 700-704 ◽  
Author(s):  
B. V. Dayakar ◽  
N. N. Narayanan ◽  
S. S. Gnanamanickam
Keyword(s):  
Mating Type ◽  
Andhra Pradesh ◽  
Magnaporthe Grisea ◽  
Finger Millet ◽  
Fragment Length Polymorphism ◽  
Rice Blast Fungus ◽  
Mating Types ◽  
Andaman Islands ◽  
Cross Compatibility ◽  
Pathogenicity Tests

Two hundred twenty-seven isolates of Magnaporthe grisea isolated from blast-infected rice tissues from different states of India were tested with MAT1-1 and MAT1-2 fertile standard testers to determine their mating type. Of the 227 monoconidial isolates, 90 (39.6%) were fertile and 137 (60.4%) were infertile and did not produce perithecia when mated with any of the four testers. In the states of Meghalaya and Himachal Pradesh, both mating types were found. In the states of Andaman Islands, Andhra Pradesh, Karnataka, Haryana, and Punjab, only mating type MAT1-1 was identified. In states where MAT1-2 occurred, its frequency was low. Among the 90 fertile isolates, 40 (44.4%) produced perithecia, asci, and ascospores, and 11 of those isolates produced perithecia, asci, and ascospores with both MAT1-2 testers, KA-9 of finger millet, and GUY11 of rice origin. However, when monoconidial isolates were mated among themselves, isolates from the same field produced only barren perithecia. Pathogenicity tests of the ascospore progeny derived from crosses of field isolates and host-specific testers revealed that none of the ascospore progeny were as virulent as the parents, despite showing compatible reactions with both rice and finger millet cultivars. These results indicate that recombinant progeny may be at a selective disadvantage despite having an increased host range. This is the first report of the occurrence of high levels of fertility (24 to 52%) in rice isolates of M. grisea in different states of India. In a Southern blot analysis, 58% of 74 isolates were identified as MAT1-1 and 41% as MAT1-2. In this population, 23 Magnaporthe grisea repeat (MGR)-restriction fragment length polymorphism groups or lineages were identified. In terms of lineage composition, the 18 isolates from Meghalaya showed maximal diversity with nine lineages.

scholarly journals Rmg8, a New Gene for Resistance to Triticum Isolates of Pyricularia oryzae in Hexaploid Wheat

2015 ◽  
Vol 105 (12) ◽  
pp. 1568-1572 ◽  
Author(s):  
Vu Lan Anh ◽  
Nguyen Tuan Anh ◽  
Analiza Grubanzo Tagle ◽  
Trinh Thi Phuong Vy ◽  
Yoshihiro Inoue ◽  
...  
Keyword(s):  
Simple Sequence Repeat ◽  
Magnaporthe Grisea ◽  
Molecular Mapping ◽  
Single Gene ◽  
Tetraploid Wheat ◽  
Pyricularia Oryzae ◽  
Avirulence Gene ◽  
Simple Sequence Repeat Markers ◽  
New Gene ◽  
Simple Sequence

Blast, caused by Pyricularia oryzae, is one of the major diseases of wheat in South America. We identified a new gene for resistance to Triticum isolates of P. oryzae in common wheat ‘S-615’, and designated it “resistance to Magnaporthe grisea 8” (Rmg8). Rmg8 was assigned to chromosome 2B through molecular mapping with simple-sequence repeat markers. To identify an avirulence gene corresponding to Rmg8, Triticum isolate Br48 (avirulent on S-615) was crossed with 200R29 (virulent on S-615), an F1 progeny derived from a cross between an Eleusine isolate (MZ5-1-6) and Br48. Segregation analysis of their progeny revealed that avirulence of Br48 on S-615 was conditioned by a single gene, which was designated AVR-Rmg8. AVR-Rmg8 was closely linked to AVR-Rmg7, which corresponded to Rmg7 located on chromosome 2A of tetraploid wheat.

In vitro evaluation of bio-agents against Pyricularia oryzae (Cav.) causing rice blast disease

2017 ◽  
Vol 37 (03) ◽  
Author(s):  
Akhilesh Kumar Kulmitra ◽  
Neha Sahu ◽  
V.B. Sanath Kumar ◽  
Thejesha A. G. ◽  
Amlan Ghosh ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Pseudomonas Fluorescens ◽  
Rice Blast ◽  
Mycelial Growth ◽  
Trichoderma Viride ◽  
Culture Technique ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
Dual Culture

The five different bio-agents viz., Trichoderma viride, T. harzianum, T. virens, Pseudomonas fluorescens and Bacillus subtilis were evaluated against Pyricularia oryzae at four and eight days after incubation through dual culture technique. Among the five different bio-agents, highest per cent inhibition of mycelial growth of fungus was recorded in T. virens i.e. 67 per cent and 70 percent after four and eight days after incubation respectively with mean of 68.5 per cent followed by Trichoderma viride with the inhibition of 61 and 63 per cent respectively with mean of 62 per cent. The Pseudomonas fluorescens did not show any inhibition of mycelial growth of P. oryzae as the pathogen over grew the bio-agents.

Selection for mating competence in Magnaporthe grisea pathogenic to rice

1991 ◽  
Vol 69 (10) ◽  
pp. 2130-2134 ◽  
Author(s):  
Chih-Cheng T. Chao ◽  
Albert H. Ellingboe
Keyword(s):  
Key Words ◽  
Mating Type ◽  
Rice Blast ◽  
Magnaporthe Grisea ◽  
Opposite Mating Type ◽  
Selection For ◽  
Sib Selection ◽  
Selection Of

Sib selection for mating competence among isolates of Magnaporthe grisea that are pathogenic on rice has led to the selection of isolates where the mating type alleles are the only restriction on mating competence. Isolates are able to mate with all sibling isolates of opposite mating type and produce asci with ascospores. Isolates can function as male, female, or hermaphrodite in mating depending on the isolates with which they are mated. Mating competence is controlled by the genes in both mated isolates. Key words: mating competence, sib selection, rice blast, genetics.

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