scholarly journals Pathogenicities of Rice Blast (Pyricularia oryzae Cavara) Isolates From Kenya

Plant Disease ◽  
2019 ◽  
Vol 103 (12) ◽  
pp. 3181-3188 ◽  
Author(s):  
Yoshimichi Fukuta ◽  
Mary Jeanie Telebanco-Yanoria ◽  
Nagao Hayashi ◽  
Seiji Yanagihara ◽  
Catherine Wanjiku Machungo ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Rice Blast ◽  
Pyricularia Oryzae ◽  
The Other ◽  
Tana River ◽  
Geographical Regions ◽  
Differential Varieties ◽  
Reaction Patterns

A total of 99 isolates of rice blast (Pyricularia oryzae Cavara) were collected from 2010 to 2015 from four regions in Kenya: Kirinyaga County and Embu County, Kisumu County, Tana River County, and Mombasa County. The pathogenicities of these isolates were clarified based on the reaction patterns of Lijiangxintuanheigu and differential varieties (DVs) targeting 23 resistance genes. The frequency of virulent isolates was high for DVs for Pib, Pia, Pii, Pi3, Pi5(t), Pik-s, Pik-m, Pi1, Pik-h, Pik, Pik-p, Pi7(t), Pi19(t), and Pi20(t); low for DVs for Pish, Pi9(t), Piz-5, and Piz-t; and intermediate for the remaining DVs for Pit, Piz, Pita-2, Pita, and Pi12(t). These blast isolates were classified into three cluster groups: Ia, Ib, and II. The frequencies of virulent isolates to DVs for Pit, Pii, Pik-m, Pi1, Pik-h, Pik, Pik-p, Pi7(t), Piz, and Pi12(t) differed markedly between clusters I and II, and those of DVs for Pib, Pit, Pia, Pi3, Pita-2, Pita, and Pi20(t) differed between Ia and Ib. The frequencies of cluster groups in the four geographical regions were different. A total of 62 races were found, with 19 blast isolates categorized into one race (U63-i7-k177-z00-ta003), whereas the other races included only some isolates in each.

scholarly journals Diversity and Distribution of Rice Blast (Pyricularia oryzae Cavara) Races in Vietnam

Plant Disease ◽  
2020 ◽  
Vol 104 (2) ◽  
pp. 381-387 ◽  
Author(s):  
Nguyen T. M. Nguyet ◽  
Hoang H. Long ◽  
Nguyen B. Ngoc ◽  
Nguyen T Nhai ◽  
Nguyen T. T. Thuy ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Rice Blast ◽  
Pyricularia Oryzae ◽  
Red River ◽  
Red River Delta ◽  
North Central ◽  
South Central ◽  
Central Vietnam ◽  
Differential Varieties ◽  
Reaction Patterns

A total of 239 isolates of blast (Pyricularia oryzae Cavara) collected from northern and central Vietnam showed a wide variation in pathogenicity based on the reaction patterns to 25 differential varieties (DVs) harboring 23 resistance genes and susceptible cultivar Lijiangxintuanheigu (LTH). The frequencies of isolates virulent toward DVs for Pish, Pik-m, Pi1, Pik-h, Pik, Pik-p, Pi7(t), Pi9(t), Piz-5, Pita-2, and Pita were low, but they were high for DVs for Pib, Pit, Pia, Pii, Pi3, Pi5(t), Pik-s, Piz, Piz-t, Pi12(t), Pi19(t), and Pi20(t). Isolates were classified into three cluster groups Ia, Ib, and II based on reaction patterns to DVs and LTH. The frequencies of isolates virulent toward 11 DVs for Pik-m, Pi1, Pik-h, Pik, Pik-p, Pi7(t), Pi9(t), Piz, Piz-5, Pita-2, and Pita in cluster II and DV for Piz-t were higher and lower than those of Ia and Ib, respectively. The frequencies to DVs for Pii, Pi3, Pi5(t), and Piz-t were different between clusters Ia and Ib. Clusters Ia and Ib were distributed with similar frequencies in the northeast, north central, and south central coast regions, but the frequencies among three cluster groups in the Red River Delta and northwest regions were different. This means that the blast races in these two regions were different from the others. Overall, the blast isolates were categorized into 153 races. Among them, 26 were selected as a set of standard differential blast isolates for characterizing 23 resistance genes and developing a differential system in Vietnam.

Pathogenicity of Isolates of the Rice Blast Pathogen (Pyricularia oryzae) from Indonesia

Plant Disease ◽  
2020 ◽  
Author(s):  
Santoso Kadeawi ◽  
Suwarno Non ◽  
Anggiani Nasution ◽  
Aris Hairmansis ◽  
Mitsuhiro Obara ◽  
...  
Keyword(s):  
Differential System ◽  
Resistance Genes ◽  
Rice Blast ◽  
Pyricularia Oryzae ◽  
The Other ◽  
Blast Disease ◽  
Rice Cultivars ◽  
Rice Ecosystems ◽  
Susceptible Control ◽  
Differential Varieties

A total of 201 isolates of Pyricularia oryzae (the causal agent of rice blast) were collected from three rice ecosystems (upland, lowland, and swampy) in five regions of Indonesia (West Java, Lampung, South Sumatra, Kalimantan, and Bali). Their pathogenicities were characterized based on the patterns of reaction of 25 differential varieties (DVs) and the susceptible control Lijiangxintuanheigu (LTH), which was susceptible to all blast isolates. A high proportion of isolates (>80.0%) were virulent to DVs for resistance genes Pib, Pit, Pia, Pik-s, and Pi12(t), and a low proportion of isolates (<12.9%) were virulent to DVs for Pik-m, Pi1, Pik-h, Pik, Pik-p, and Pi7(t). Virulence to the other DVs for Pish, Pii, Pi3, Pi5(t), Pi9(t), Piz, Piz-5, Piz-t, Pita-2 (two lines), Pita (two lines), Pi19(t), and Pi20(t) showed intermediate frequencies from 20.0% to 80.0%. These isolates were classified into three cluster groups Ia, Ib, and II, and the frequencies of cluster groups varied among the three ecosystems and the five regions. The frequencies of cluster groups varied among the different ecosystems and regions, and races varied according to the ecosystems. A total of 27 standard differential blast isolates (SDBLs) were selected from the 201 isolates collected. The set of 25 DVs and these 27 SDBIs will be used as a new differential system for analysis of the pathogenicity of blast isolates and analysis of resistance genes in rice cultivars, which will contribute to building up a durable protection system against blast disease in Indonesia.

scholarly journals Diversity and Distribution of Rice Blast (Pyricularia oryzae Cavara) Races in Bangladesh

Plant Disease ◽  
2016 ◽  
Vol 100 (10) ◽  
pp. 2025-2033 ◽  
Author(s):  
M. A. I. Khan ◽  
M. A. Ali ◽  
M. A. Monsur ◽  
A. Kawasaki-Tanaka ◽  
N. Hayashi ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Resistance Genes ◽  
Rice Blast ◽  
Blast Resistance ◽  
Pyricularia Oryzae ◽  
Blast Protection ◽  
Blast Resistance Gene ◽  
Group I ◽  
Differential Varieties ◽  
Reaction Patterns

The pathogenicity of 331 blast isolates (Pyricularia oryzae Cavara) collected from different regions and ecosystems for rice cultivation in Bangladesh was evaluated by compatibility on 23 differential varieties (DV), each harboring a single blast resistance gene, and susceptible ‘Lijiangxintuanheigu’ (LTH). A wide variation in virulence was found among the isolates, and 267 races were classified using a new designation system. Virulence of blast isolates against DV carrying the resistance genes Pia, Pib, Pit, Pik-s, Piz-t, Pi12(t), Pi19(t), and Pi20(t), as well as avirulence against those carrying Pish, Pi9, Pita-2, and Pita, was distributed widely in Bangladesh. Cluster analysis of the compatibility data on the DV initially classified the isolates into groups I and II. The virulence spectra of the two groups differed mainly according to the reactions of the DV to Pii, Pi3, Pi5(t), Pik-m, Pi1, Pik-h, Pik, Pik-p, and Pi7(t). Group I isolates were distributed mainly in rainfed lowlands, whereas group II isolates were found mainly in irrigated lowlands; however, there were no critical differences in geographic distribution of the blast isolates. In total, 26 isolates, which could be used to identify the 23 resistance genes of the DV on the basis of their reaction patterns, were selected as a set of standard differential blast isolates. To our knowledge, this is the first clear demonstration of the diversity and differentiation of blast races in Bangladesh. This information will be used to develop a durable blast protection system in that country.

scholarly journals Diversity and Distribution of Rice Blast (Pyricularia oryzae Cavara) Races in Japan

Plant Disease ◽  
2016 ◽  
Vol 100 (4) ◽  
pp. 816-823 ◽  
Author(s):  
A. Kawasaki-Tanaka ◽  
N. Hayashi ◽  
S. Yanagihara ◽  
Y. Fukuta
Keyword(s):  
Cluster Analysis ◽  
Rice Blast ◽  
Oryza Sativa L ◽  
Pyricularia Oryzae ◽  
Central Japan ◽  
Original Population ◽  
Group I ◽  
Differential Varieties ◽  
Reaction Patterns ◽  
Northern Japan

In total, 310 rice blast (Pyricularia oryzae Cavara) isolates from Japan showed wide variation in virulence. Virulence on rice (Oryza sativa L.) differential varieties (DV) harboring resistance genes Pish, Pia, Pii, Pi3, Pi5(t), Pik-s, and Pi19(t) ranged from 82.9 to 100.0%. In contrast, virulence on DV possessing Pib, Pit, Pik-m, Pi1, Pik-h, Pik, Pik-p, Pi7(t), Pi9(t), Piz, Piz-5, Piz-t, Pita-2, Pita, Pi12(t), and Pi20(t) ranged from 0 to 21.6%. Cluster analysis using the reaction patterns of the DV classified isolates into three groups: I, virulent to Pik, Pik-h, Pik-p, Pik-m, Pi1, and Pi7(t); IIa, avirulent to the preceding 6 genes and virulent to Pia, Pii, Pi3, and Pi5(t); and IIb, avirulent to all 10 genes. Group I was limited to northern Japan and group IIb to central Japan, while group IIa was distributed throughout Japan. We estimate that group IIa represents the original population and that groups I and IIb arose from it through minor changes in pathogenicity. We classified these isolates into 123 races by a new designation system and conclude that the rice blast races in Japan are less diverse than previously thought.

scholarly journals Virulence Pattern of Pyricularia oryzae Pathotypes Towards Blast Monogenic Lines

2021 ◽  
Vol 32 (3) ◽  
pp. 147-160
Author(s):  
Siti Norsuha Misman ◽  
Mohd Shahril Firdaus Ab Razak ◽  
Nur Syahirah Ahmad Sobri ◽  
Latiffah Zakaria
Keyword(s):  
Resistance Genes ◽  
Rice Blast ◽  
Blast Resistance ◽  
Rice Variety ◽  
Durable Resistance ◽  
Peninsular Malaysia ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
Breeding Lines ◽  
Virulence Pattern

Rice blast caused by Pyricularia oryzae (P. oryzae) is one of the most serious diseases infecting rice worldwide. In the present study, virulence pattern of six P. oryzae pathotypes (P0.0, P0.2, P1.0, P3.0, P7.0 and P9.0) identified from the blast pathogen collected in Peninsular Malaysia, were evaluated using a set of 22 IRRI-bred blast resistance lines (IRBL) as well as to determine the resistance genes involved. The information on the virulence of the blast pathotypes and the resistance genes involved is important for breeding of new rice variety for durable resistance against blast disease. The IRBL was established from 22 monogenic lines, harbouring 22 resistance genes [Pia, Pib, Pii, Pit, Pi3, Pi5(t), Pish, Pi1, Pik, Pik-s, Pik-m, Pik-h, Pik-p, Pi7(t), Pi9, Piz, Piz-5, Piz-t, Pi19, Pi20(t), Pita-2, and Pita=Pi4(t)]. Based on the disease severity patterns, the tested pathotypes were avirulence towards seven IRBLs [IRBLi-F5, IRBLk-Ka, IRBLkh-K3, IRBLz-Fu, IRBLsh-S, IRBLPi7 (t) and IRBL9-W] of which these IRBLs harbouring Pii, Pik, Pik-h, Piz, Pish, Pi7(t) and Pi9 resistance genes, respectively. Therefore, the results suggested that the seven IRBLs carrying seven resistance genes [Pii, Pik, Pik-h, Piz, Pish, Pi7(t) and Pi9] would be suitable candidates of resistance genes to be incorporated in new breeding lines to combat the current blast pathotypes in the field.

scholarly journals Efectividad biológica del Azoxystrobin para el control de Pyricularia oryzae Cav. y Cercospora oryzae Miyake en el cultivo de arroz de temporal en Veracruz, México.

2006 ◽  
Vol 12 (1) ◽  
pp. 105 ◽  
Author(s):  
Enrique Becerra ◽  
Oscar Tosquy
Keyword(s):  
Grain Yield ◽  
Rice Blast ◽  
Block Design ◽  
Rice Variety ◽  
Good Control ◽  
Pyricularia Oryzae ◽  
The Other ◽  
Intensity Index ◽  
Randomized Complete Block Design ◽  
Better Than

In the state of Veracruz, Mexico, around 22000 ha of rice are sown annually; the average of yield is about 3.5 t/ha and it is mainly due to drought problems, which favours the presence of the fungi Pyricularia oryzae Cav. (rice blast) and Cercospora oryzae Miyake (narrow spot). In order to know the behavior of new fungicides, the effectiveness of Azoxystrobin on the control of these fungi was evaluated. The experiment was established in the municipality of Tres Valles, Veracruz, at the beginning of the 1999 rainy season. Seed of the rice variety Milagro Filipino Depurado was used. The experimental design was a Randomized Complete Block design with four replications. The evaluated treatments were: Azoxystrobin at 0.2, 0.4 and 0.6 l/ha vs Tecto60 at 0.5 kg/ha and a non-treated control.These treatments were applied when the first symptoms of rice blast and/or narrow spot were noticed. Factors being evaluate were: incidence, number of lesions in 20 plants, intensity index, phytotoxicity and grain yield. Azoxystrobin controlled both diseases better than Tecto 60; on the other hand, rice plants treated with Tecto 60 had significantly less lesions than the non-treated plants. The best control of P. oryzae and C. oryzae and the highest grain yield (4432 kg/ha) were obtained when Azoxystrobin was applied at 0.6 l/ha, although a good control of both diseases was also attained at 0.2 and 0.4 l/ha. None of the fungicides caused toxicity to rice.

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 Structural Investigation and Molecular Modeling Studies of Strobilurin-Based Fungicides Active against the Rice Blast Pathogen Pyricularia oryzae

2021 ◽  
Vol 22 (7) ◽  
pp. 3731
Author(s):  
Andrea Kunova ◽  
Luca Palazzolo ◽  
Fabio Forlani ◽  
Giorgia Catinella ◽  
Loana Musso ◽  
...  
Keyword(s):  
Rice Blast ◽  
Rational Design ◽  
Structural Investigation ◽  
Resistance Mechanism ◽  
Three Dimensional ◽  
Pyricularia Oryzae ◽  
Cytochrome Bc1 ◽  
Cytochrome Bc1 Complex ◽  
Three Dimensional Model ◽  
Resistant Strains

The increasing emergence of fungicide-resistant pathogens requires urgent solutions for crop disease management. Here, we describe a structural investigation of new fungicides obtained by combining strobilurin and succinate dehydrogenase inhibitor pharmacophores. We identified compounds endowed with very good activity against wild-type Pyricularia oryzae, combined in some cases with promising activity against strobilurin-resistant strains. The first three-dimensional model of P. oryzae cytochrome bc1 complex containing azoxystrobin as a ligand was developed. The model was validated with a set of commercially available strobilurins, and it well explains both the resistance mechanism to strobilurins mediated by the mutation G143A and the activity of metyltetraprole against strobilurin-resistant strains. The obtained results shed light on the key recognition determinants of strobilurin-like derivatives in the cytochrome bc1 active site and will guide the further rational design of new fungicides able to overcome resistance caused by G143A mutation in the rice blast pathogen.

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