Analysis of <i>Pyricularia grisea</i> populations from three different blast epidemics

Abstract

In spite of a great deal of research on the blast pathogen (Pyricularia grisea (Cooke) Sacc., an anamorph of Magnaporthe grisea (T.T. Hebert) Yaegashi & Udegawa) of rice and the disease itself, blast remains a serious constraint to rice production in areas with conducive environments and where susceptible cultivars are grown. There has been no effort to analyze the pathogen populations that occurred during the blast epidemics in India. Three of these epidemics occurred in the state of Orissa in the past decade. The first epidemic was in Banki, Cuttack District, in the 1997 wet season, during which traditional rice cultivars Laghubhutia and Golabondi were heavily infected by neck blast. The second epidemic, in the wet season of 2000 in Dhenkanal, Dhenkanal District, involved traditional cultivar Latamohu and high-yielding semidwarf Dhala Heera. They got severely infected by leaf blast. During the third epidemic (2002 wet season, Ganjam District), high-yielding variety Swarna grown in farmers' fields was severely infected by leaf blast.