INCIDENCE OF KARNAL BUNT (TILLETIA INDICA MITRA) OF WHEAT (TRITICUM AESTIVUM L.) IN TWO DISTRICTS OF PUNJAB (PAKISTAN) AND IDENTIFICATION OF RESISTANCE SOURCE

Abstract

Wheat is considered as an important staple food crop around world. It endures significant yield losses due to several biotic and abiotic factors. Among biotic agents, Tilletia indica causing karnal bunt, attributes more than 39% yield losses. Two districts of Punjab (Pakistan), viz. Rawalpindi and Chakwal, were selected and 275 fields were randomly surveyed during wheat growing period in 2011-12 to check the prevalence and incidence of karnal bunt. Maximum disease prevalence was observed in Chakwal (50%) as compared to Rawalpindi (35%). Village Chakri in Rawalpindi and Village Mangwal in Chakwal exhibited highest disease incidence of 9.98% and 10.34% respectively. From suspected samples, teliospores were isolated and mass cultured. 119 wheat advance lines and 11 commercial varieties were artificially inoculated with inoculum prepared to check the degree of susceptibility of wheat varieties/advance lines against karnal bunt under environmental conditions of Rawalpindi and Islamabad. From advance lines, ‘MN-8’ and ‘MN-26’ were found to be susceptible with 10.2 and 19.2 coefficient of infections, and from commercial varieties, ‘Kohinoor-83’ with 7.73 coefficient of infection was moderately susceptible.