Virulence analysis of Pyricularia oryzae isolates causing wheat blast in Bangladesh

2021 ◽  
Vol 30 (2) ◽  
pp. 151-157
Author(s):  
Md Abdullah Al Noman ◽  
Shamim Shamsi
Keyword(s):  
Plant Pathology ◽  
Plant Pathogen ◽  
Pyricularia Oryzae ◽  
Causal Agent ◽  
Pathology Laboratory ◽  
Wheat Varieties ◽  
Pathogenic Potential ◽  
Wheat Blast ◽  
Virulence Analysis ◽  
High Virulence

Mycology and Plant Pathology Laboratory, Department of Botany, University of Dhaka, Dhaka-1000, Bangladesh Pyricularia oryzae pathotype Triticum, causal agent of wheat blast, has emerged in Bangladesh as a serious threat for wheat production. Virulence analysis of plant pathogen can reveal the pathogenic nature of that pathogen. In the present study, twenty-four monoconidial isolates of P. oryzae from Chuadanga, Meherpur, Kustia and Jhenaidaha districts of Bangladesh were analyzed to observe their pathogenic potential. Based on the disease reactions, all the isolates were grouped into 3 pathotypes. Present investigation revealed that the isolates with high virulence were prevalent in the studied P. oryzae population. Again, Pathotype 1 that was identified as the most virulent can be used as reference for screening resistant wheat varieties. Dhaka Univ. J. Biol. Sci. 30(2): 151-157, 2021 (July)

scholarly journals Conidia sporulation of Pyricularia oryzae in segments of wheat plants under six different temperatures

2020 ◽  
Vol 50 (4) ◽  
Author(s):  
Marcos Kovaleski ◽  
João Leodato Nunes Maciel ◽  
Gustavo Bilibio dos Santos ◽  
Alieze Nascimento da Silva ◽  
Carolina Cardoso Deuner
Keyword(s):  
High Temperature ◽  
Petri Dish ◽  
Pyricularia Oryzae ◽  
Causal Agent ◽  
Temperature Conditions ◽  
Wheat Blast ◽  
Conidia Production ◽  
Different Temperatures

ABSTRACT: Wheat blast is known for developing itself more intensely under relatively high temperature conditions but many aspects related to its epidemiology remain unknown. The objective of this research was to evaluate the sporulative capacity of Pyricularia oryzae Triticum (Pot), the causal agent of wheat blast, in tissues of wheat plants under different temperatures degrees. Wheat plants of the cultivar Anahuac 75, susceptible to blast, were inoculated in the stage of flowering with conidial suspensions (105 conidia/mL) of the Pot isolates Py 12.1.209 and Py 12.1.132. Seven days after the inoculation, plants were cut in the following segments: leaves, stems and rachis (with blast severity ranging from 40 to 60%). Groups of each one of the three plant segments with the lesions were disposed in Petri-dish moist chambers, that were submitted to six different temperature treatments (18, 21, 24, 27, 30 and 33 °C). The most appropriate model that related the conidia production with temperature was identified in the evaluations conducted with stems. The established equations allowed identifying that the highest production of conidia of Pot occurs between 24 and 27 °C.

The Plant Pathology Laboratory, Harpenden

Nature ◽  
1960 ◽  
Vol 187 (4731) ◽  
pp. 21-23
Author(s):  
W. C. MOORE
Keyword(s):  
Plant Pathology ◽  
Pathology Laboratory

Pathotype Identification and Virulence Variation in Cochliobolus sativus in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Lin Chen ◽  
Quanjie Yao ◽  
Fengtao Wang ◽  
Yunxing Pang ◽  
Xiaowei Lang ◽  
...  
Keyword(s):  
Regional Climate ◽  
Cochliobolus Sativus ◽  
Wheat Varieties ◽  
Geographic Origins ◽  
High Virulence ◽  
Wheat Leaves ◽  
Barley Genotypes ◽  
Important Disease ◽  
Wheat Tissues ◽  
Virulence Variation

Spot blotch caused by Cochliobolus sativus has become an important disease in the wheat-growing regions in China due to changes of regional climate, agricultural cultivation pattern and widely growing susceptible wheat varieties. Little information is available about virulence variability and pathogenic specialization of the C. sativus isolates from major wheat-growing regions in China. Here, 12 representative wheat varieties and foundation breeding stocks were selected to characterize the pathotypes of C. sativus isolates from infected wheat plants. Based on the infection phenotypes in the 12 differential genotypes at the seedling stage, 70 Chinese pathotypes were identified from 110 isolates and clustered into three virulence groups. The high virulence isolates were collected from wheat leaves, crowns, and roots, with most (10 of 14) from the Henan province in the Huang-Huai plain. No relationship was evident between virulence variability of C. sativus isolates and their geographic origins or types of diseased wheat tissues. Cochliobolus sativus showed a significant pathogenic specialization in hosts of wheat and barley. Most of the wheat isolates (50 of 65) were avirulent to all the differential barley genotypes, and a few were virulent only to highly susceptible barley genotypes. These results indicated that C. sativus isolates from the wheat-growing regions in China varied considerably for their virulence in wheat varieties, and showed significant pathogenic specialization to the wheat and barley hosts.

The risk of wheat blast in rice-wheat-co-planting regions in China: MoO strains of Pyricularia oryzae cause typical symptom and host reaction on both wheat leaves and spikes

2021 ◽  
Author(s):  
Shizhen Wang ◽  
Jiaoyu Wang ◽  
Zhen Zhang ◽  
Zhongna Hao ◽  
Xueming Zhu ◽  
...  
Keyword(s):  
Global Warming ◽  
Pyricularia Oryzae ◽  
Wheat Cultivars ◽  
Host Reaction ◽  
Typical Symptom ◽  
Wheat Blast ◽  
Resistant Genes ◽  
Wheat Leaves ◽  
Cultivar Specificity ◽  
Heading Stage

Triticum pathotype (MoT) of Magnaporthe oryzae (syn. Pyricularia oryzae) causes wheat blast, which has recently spread to Asia. To assess the potential risk of wheat blast in rice-wheat growing regions, we investigated the pathogenicity of 14 isolates of P. oryzae on 32 wheat cultivars, among which MoO isolates were completely avirulent on the wheat cultivars at 22℃, but caused various infection degrees at 25℃. These reactions at 25℃ were isolate- and cultivar- dependent like race-cultivar specificity which was also recognized at the heading stage and caused typical blast symptoms on spikes. Microscopic analyses indicated that a compatible MoO isolates produced appressoria and infection hyphae on wheat as on rice. By comparing transcriptomes in wheat-MoO interactions, a bulk of pathogen-related genes was up-/down- regulated in compatible and incompatible patterns, but that changes of gene transcription were more significant in compatible pattern. These results indicate that the temperature could influence the infection ratio of wheat with MoO, and some MoO strains could be potential pathogens that increase the risk for the outbreak of wheat blast in wheat-rice growing regions with global warming. In addition, certain wheat cultivars exhibited resistance and are assumed to carry promoting resistant genes to the MoO strains.

scholarly journals Tracing the Origin and Evolutionary History of Pyricularia oryzae Infecting Maize and Barnyard Grass

2020 ◽  
pp. PHYTO-09-20-042
Author(s):  
Adel Pordel ◽  
Sebastien Ravel ◽  
Florian Charriat ◽  
Pierre Gladieux ◽  
Sandrine Cros-Arteil ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Host Range ◽  
Range Expansion ◽  
Pyricularia Oryzae ◽  
Causal Agent ◽  
Blast Disease ◽  
Yield Losses ◽  
Barnyard Grass ◽  
Host Range Expansion ◽  
Recent Emergence

Blast disease is a notorious fungal disease leading to dramatic yield losses on major food crops such as rice and wheat. The causal agent, Pyricularia oryzae, encompasses different lineages, each having a different host range. Host shifts are suspected to have occurred in this species from Setaria spp. to rice and from Lolium spp. to wheat. The emergence of blast disease on maize in Iran was observed for the first time in the north of the country in 2012. We later identified blast disease in two additional regions of Iran: Gilan in 2013 and Golestan in 2016. Epidemics on the weed barnyard grass (Echinochloa spp.) were also observed in the same maize fields. Here, we showed that P. oryzae is the causal agent of this disease on both hosts. Pathogenicity assays in the greenhouse revealed that strains from maize can infect barnyard grass and conversely. However, genotyping with simple sequence repeat markers and comparative genomics showed that strains causing field epidemics on maize and on barnyard grass are different, although they belong to the same previously undescribed clade of P. oryzae. Phylogenetic analyses including these strains and a maize strain collected in Gabon in 1985 revealed two independent host-range expansion events from barnyard grass to maize. Comparative genomics between maize and barnyard grass strains revealed the presence or absence of five candidate genes associated with host specificity on maize, with the deletion of a small genomic region possibly responsible for adaptation to maize. This recent emergence of P. oryzae on maize provides a case study to understand host range expansion. Epidemics on maize raise concerns about potential yield losses on this crop in Iran and potential geographic expansion of the disease.

scholarly journals A Genomic Approach to Develop a New qPCR Test Enabling Detection of the Pyricularia oryzae Lineage Causing Wheat Blast

Plant Disease ◽  
2020 ◽  
Vol 104 (1) ◽  
pp. 60-70 ◽  
Author(s):  
Maud Thierry ◽  
Pierre Gladieux ◽  
Elisabeth Fournier ◽  
Didier Tharreau ◽  
Renaud Ioos
Keyword(s):  
Genomic Analysis ◽  
High Sensitivity ◽  
Fungal Species ◽  
Emerging Diseases ◽  
Pyricularia Oryzae ◽  
Blast Disease ◽  
South American ◽  
Analytical Sensitivity ◽  
Wheat Blast ◽  
Pcr Test

Rapid detection is key to managing emerging diseases because it allows their spread around the world to be monitored and limited. The first major wheat blast epidemics were reported in 1985 in the Brazilian state of Paraná. Following this outbreak, the disease quickly spread to neighboring regions and countries and, in 2016, the first report of wheat blast disease outside South America was released. This Asian outbreak was due to the trade of infected South American seed, demonstrating the importance of detection tests in order to avoid importing contaminated biological material into regions free from the pathogen. Genomic analysis has revealed that one particular lineage within the fungal species Pyricularia oryzae is associated with this disease: the Triticum lineage. A comparison of 81 Pyricularia genomes highlighted polymorphisms specific to the Triticum lineage, and this study developed a real-time PCR test targeting one of these polymorphisms. The test’s performance was then evaluated in order to measure its analytical specificity, analytical sensitivity, and robustness. The C17 quantitative PCR test detected isolates belonging to the Triticum lineage with high sensitivity, down to 13 plasmid copies or 1 pg of genomic DNA per reaction tube. The blast-based approach developed here to study P. oryzae can be transposed to other emerging diseases.

scholarly journals A Clone Resource of Magnaporthe oryzae Effectors That Share Sequence and Structural Similarities Across Host-Specific Lineages

2020 ◽  
Vol 33 (8) ◽  
pp. 1032-1035 ◽  
Author(s):  
Yohann Petit-Houdenot ◽  
Thorsten Langner ◽  
Adeline Harant ◽  
Joe Win ◽  
Sophien Kamoun
Keyword(s):  
Open Source ◽  
Clone Library ◽  
Magnaporthe Oryzae ◽  
Plant Pathogen ◽  
Host Species ◽  
Pyricularia Oryzae ◽  
Golden Gate ◽  
Functional Studies ◽  
Specific Host ◽  
Blast Fungus

The blast fungus Magnaporthe oryzae (syn. Pyricularia oryzae) is a destructive plant pathogen that can infect about 50 species of both wild and cultivated grasses, including important crops such as rice and wheat. M. oryzae is composed of genetically differentiated lineages that tend to infect specific host genera. To date, most studies of M. oryzae effectors have focused on the rice-infecting lineage. We describe a clone resource of 195 effectors of Magnaporthe species predicted from all the major host-specific lineages. These clones are freely available as Golden Gate–compatible entry plasmids. Our aim is to provide the community with an open source effector clone library to be used in a variety of functional studies. We hope that this resource will encourage studies of M. oryzae effectors on diverse host species.

A New Black Raspberry Aphid

1954 ◽  
Vol 86 (5) ◽  
pp. 235-236 ◽  
Author(s):  
George F. Knowlton
Keyword(s):  
Plant Pathology ◽  
Black Raspberry ◽  
Pathology Laboratory ◽  
Rubus Occidentalis ◽  
Leaf Symptoms

An apparently undescribed Amphorophora was received from Richard Stace-Smith of the Canada Agriculture Plant Pathology Laboratory, Vancouver, B.C., Canada. This species produced leaf symptoms on Munger black raspberry, Rubus occidentalis, which differed from anything associated with the feeding of Amphorophora rubi (Kaltenbach). An examination was made of the material by Professor M. A. Palmer, Dr. F. C. Hottes and the writer. This failed to place this blackberry aphid as a described species. Therefore, it is here described as new.

scholarly journals William Pollock Fraser (1867-1943) : Canadian pioneer plant pathologist-mycologist

2005 ◽  
Vol 73 (2) ◽  
pp. 53-59
Author(s):  
R.H. Estey
Keyword(s):  
Plant Pathology ◽  
Nova Scotia ◽  
Rust Fungi ◽  
Western Canada ◽  
Forest Pathology ◽  
Pathology Laboratory ◽  
Pioneer Plant ◽  
Mcgill University ◽  
The University ◽  
Wheat Rust

William P. Fraser, the first Canadian-born plant pathologist-mycologist to be internationally recognized as such, began as an amateur collector of fungi, with emphasis on the plant rusts, while teaching school in his home province, Nova Scotia. He then became a widely acclaimed authority on the rusts and a professional plant pathologist-mycologist. He taught plant pathology and mycology, first at McGill University and then, after an interval as head of the first plant pathology laboratory in Western Canada, at the University of Saskatchewan. Fraser was a Canadian pioneer in research on physiological races of wheat rust; in the culture of heteroecious rust fungi, in forest pathology, and in the study of root and smut diseases of grasses in Western Canada.

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