1Department of Genetics and Plant Breeding, UAS, Gandhi Krishi Vignan Kendra, Bangalore, India
2Department of Genetics and Plant Breeding, Banaras Hindu University, Varanasi, India
3Department of agriculture Statistics, Banaras Hindu University, Varanasi, India
*Corresponding author: varshapanchu@gmail.com
Online published on 13 May, 2016.
Rice blast, major fungal pathogen attacking rice limits the yield in all major rice growing regions of the world, especially in warm, high humid and dry upland environments. The population genetics of M.oryza were analyzed in three locations i.e. Mandya (Southern dry zone), Ponnampet (Hilly zone) and Bangalore for (pathogenicity test). Disease was evaluated for their pathogenic virulence and genetic characterization using Avr gene specific markers. Isolates were classified into three groups based on pathogenicity viz., seven-severely pathogenic (isolates), 11 moderately pathogenic and three mildly pathogenic isolates. Study revealed, among 21 isolates collected, Avr genes were found in 18 isolates for gene AvrPita, 15 for Avr-Pitz, four for Avr- Co-39, 12 in Avr-Pia and 8 in Avr-Pik gene. The isolates of Mandya were highly variable than Ponnampet (through cluster analysis). This study helps in understanding the response of different rice accessions to blast in different locations, the distribution and contribution of Avr genes for host plant resistance.
Highlights
• Majority of isolates were grouped under moderate virulence though pathogenisity test and molecular analysis.
• The suitable temperature for the cultural growth of all the isolates was 28±2°C. Least number of isolates were having Avr-Co-39genes.
• Through the virulence pattern and Avr gene distribution studies in leading cultivars and varieties, there is a scope in altering the pathogenicity which may pave a way for disease management.
Avr, blast disease, OMA, PDA, pathogenicity, rice
