Abstract
In comparison to other nations, wheat grain yield in our country is comparatively lower as it is badly affected by numerous biotic and abiotic stresses. Considering the abiotic stresses, heat stress is one of main issues which causes a great reduction in production in Pakistan. The present research was focused on the evaluation of the performance of elite wheat genotypes at normal and late sowing dates. For this purpose, eight wheat genotypes were sown in a randomized complete block design having three replications at the experimental farm of Nuclear Institute of Agriculture, Tandojam. The data was observed on five quantitative traits including spike length (cm), spikelets spike-1 , grain weight spike-1 , grains spike-1 and 1000 grain weight. The analysis of variance of all the genotypes at normal and high temperature exposed significant differences at P≤0.01 for all the characters, indicating the trustworthiness of used materials for future breeding experiments in order to improve bread wheat at normal and stress conditions. Low reduction in mean performance at high temperature for the traits spike length, grain weight spike-1 , grains spike-1 and 1000-grain weight was demonstrated by the cultivars AS-2002, Sehar-2006, Sundar and Kiran-95, respectively. The above mentioned elite wheat genotypes may prove better crop resources for heat stress breeding in wheat crop.
