Screening of Wheat Genotypes Under Terminal Heat Stress Conditions for the Morpho-Physiological and Yield Related Traits

Screening of Wheat Under Heat Stress

Abstract

Late sowing of wheat crop is associated with high temperatures. Thus temperature is one of the main limiting factors that influences yield production of wheat especially during the grain filling period. Heat tolerance is a complex phenomenon, which is very difficult to make a reliable assessment about it. High temperature stress is a chief ecological constraint hampering productivity of hexaploid wheat in most parts of the globe. Present research were carried out at Nuclear Institute of Agriculture Research Tandojam Sindh, which is located at approximately 25.4299 N latitude and 68.5426 E longitude, during the rabi season 2017-2018, in this context, a set of 22 bread wheat genotypes was evaluated against heat stress tolerance in glasshouse and as well as natural field conditions. A similar experiment of screening was also conducted in normal and late sowing conditions so as to expose the material under heat stress. The variances due to mean squares of both the screening experiments revealed significant differences for genotypes, treatments and treatment x genotypes interactions for studied traits. Such results indicated that genetic resources under present study are worth to be included in future breeding schemes. Based on mean performance and lower declines/reduction levels under heat stress, six out of 22 genotypes like TD-1, Benazir, TJ-83, Kiran-95, NIA-Sarang and AS-2002 were identified as heat stress tolerant for most of studied traits.