Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Virulence Analysis of Pyricularia Oryzae Isolates Causing Wheat Blast in Bangladesh

Md Abdullah Al Noman
Mycology and Plant Pathology Laboratory, Department of Botany, University of Dhaka, Dhaka-1000, Bangladesh

Shamim Shamsi
Mycology and Plant Pathology Laboratory, Department of Botany, University of Dhaka, Dhaka-1000, Bangladesh

Abstract/ Executive Summary:

Pyricularia oryzae pathotype Triticum, the causal agent of the wheat blast, has emerged in Bangladesh as a serious threat to 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. The present investigation revealed that the isolates with high virulence were prevalent in the studied P. oryzae population. Again, Pathotype 1 was identified as the most virulent can be used as a reference for screening resistant wheat varieties.

Keywords: Monoconidial isolates, Pyricularia oryzae, Disease scoring, Pathotype, Wheat

Location: Districts of Bangladesh viz., Chuadanga, Meherpur, Kustia and Jhenaidaha

Start Date: 00-00-2017

End Date: 00-00-2018

Program Area: Variety and Species

Commodity: Wheat

Objectives:

To evaluate the virulence nature of P. oryzae isolates from major wheat blast-affected districts of Bangladesh.

Methodology:

Wheat blast infected leaves and panicles were collected from the four major wheat blast affected districts of Bangladesh viz., Chuadanga, Meherpur, Kustia and Jhenaidaha during the tenure of the 2017-18 wheat season. A total of 24 monoconidial isolates were obtained through a single conidium isolation technique. All the isolates were maintained in PDA slants at 4°C. For long-term storage, isolates were grown on sterile filter paper disks and kept at -80°C. For virulence analysis, all the Pyricularia oryzae isolates were tested against two commonly cultivated wheat varieties (BARI Gom- 21 and BARI Gom- 24) in the study areas. Seed samples of these two wheat varieties were collected from Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur, Bangladesh. For inoculum preparation, stored cultures were allowed to grow on oatmeal agar (OMA) medium (Oatmeal 60 g, sucrose 2 g, agar 16 g and distilled water 1000 ml) at 25°C for two weeks. A pathogenicity test for all the isolates was performed following the method described by Hayashi et al. (2009)(17). Disease scoring was done 7 to 8 days after inoculation. Before scoring, re-isolation of the pathogen from the lesions was done to fulfill the criteria of Koch's postulates. Reaction types of selected wheat varieties against each isolate were recorded after 7 days of inoculation. Infection types were rated on a 0 - 5 disease assessment scale(16,18) where 0 = no evidence of infection; 1 = brown specks smaller than 0.5 mm in diameter, no sporulation; 2 = brown specks about 0.5 - 1.00 mm in diameter, no sporulation; 3 = roundish to elliptical lesions about 1 - 3 mm in diameter with gray center surrounded by brown margins, lesions capable of sporulation; 4 = typical spindle-shaped blast lesions capable of sporulation, 3 mm or longer with little or no coalescence of lesions; 5 = lesions as in 4 but about half of 1 - 2 leaf blades killed by coalescence of lesions. Reaction types 0 - 3 were considered resistant while 4 and 5 were considered susceptible.

Source of Information: Dhaka Univ. J. Biol. Sci. 30(2): 151-157, 2021 (July)

Article Link (Online Journal): DOI: https://doi.org/10.3329/dujbs.v30i2.54641

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

This study also indicated that BARI Gom- 21 and BARI Gom- 24 wheat varieties were found to be vulnerable against wheat blast as most of the isolates could severely infect both varieties. Furthermore, Pathotype 1 was identified as the most virulent can be used as a reference for screening resistant wheat varieties. Overall, knowledge generated in this study will be helpful in understanding the pathogenic nature of P. oryzae isolates causing wheat blast in Bangladesh.

Knowledge Management: Journal