Combining ability and gene action for grain yield and its components under high temperature environment in bread wheat [Triticum aestivum (L.) em. Theil]

Abstract

Bread wheat (Triticum aestivum L.) is a thermo-sensitive crop and adapted best to temperate climate. However, it is predominantly produced and consumed in tropical and sub tropical regions of the world, where it is exposed to high temperature stress during later stages, resulting in tremendous yield losses. Wheat crop grown in Northern India under late sown conditions is exposed to low temperature up to booting stage where it has to face higher temperature, which enables grain development under high temperature conditions leading to poor yield. Cultivars differ in their relative adaptation to hot environments irrespective of their yield performance in cool environments [1]. For development of high yielding genotypes under stress environments, information on genetic control of grain yield and associated characters under heat stress and identification of good general combiner parents/crosses are the primary requirements. This study was therefore, undertaken to identify desirable parents and crosses and to elucidate the gene action for grain yield and yield components in bread wheat using diallele mating approach under normal (N) and high temperature (HT) environments.