Pathogenic variability amongst Indian isolates of Magnaporthe grisea causing blast in pearl millet

摘要

Blast disease caused by Magnaporthe grisea is a major biotic constraint to the production of pearl millet in India. The pathogen is highly variable in nature, but isolates are mostly specific in their host range. Pathogenic variation among 80 M. grisea isolates collected from major pearl millet growing states in India was studied on pearl millet host differentials (ICMB 93333-P1, ICMB 95444, ICMB 97222-P1, ICMB 01333, ICMB 02444, ICMR 06444, 863B-P2, ICMR 06222, ICMR 11003 and IP 21187-P1) under greenhouse conditions. Based on reaction of isolates on host differentials (virulent = score >= 4 and avirulent = score <= 3 on a 1-to-9 scale), 80 isolates were clustered into 14 pathogenic groups. Based on the virulence profiling, isolates Pg 138, Pg 186, Pg 204, and Pg 232 representing different pathogenic groups, and collected from different states have been selected for greenhouse screening of pearl millet lines for blast resistance.