Stripe rust resistance in wheat germplasm of North-western Himalayan hills.

Abstract

Stripe rust of wheat is one of the major biotic stresses occurring in cooler regions of wheat production worldwide. In the present study, about 464 wheat germplasm collected from cooler areas of northern hills, India, were characterized for stripe rust resistance both at seedling and adult-plant stages. Initially, these genotypes were evaluated in the field at two locations, Hawalbagh and Dalang-Maidan during three continuous cropping seasons. Under field conditions, 22 genotypes showed a consistent expression of high field resistance (ACI<5.0), 349 expressed partial field resistance (ACI 5.0-60.0), and 93 were highly susceptible (ACI>60.0). In next season, the high field resistant genotypes were subjected to both seedling and an adult-plant stage resistance test against four virulent Pst pathotypes (78S84, 46S119, 110S119 and 238S119) under glasshouse conditions at ICAR-IIWBR, Shimla and Hawalbagh, Uttarakhand, respectively. Among 22 high resistance genotypes, 14 genotypes possessed all-stage resistance against all 4 Pst pathotypes and 4 genotypes were resistant to only two pathotypes (78S84 and 46S119) both at seedling and adult plant stages. Further, 349 partially field resistant genotypes were evaluated for adult-plant stage resistance under artificially inoculated conditions, out of which 18 genotypes were found to have adult-plant stage resistance. Seedling resistance reported in the current study is effective against newly emerged Pst pathotypes 110S119 and 238S119 and previously reported predominant pathotypes 78S84 and 46S119 in India. The stripe rust resistance genotypes identified in the current study may serve as potential donors of stripe rust resistance to wheat breeding programmes in India and elsewhere.