GENETICAL AND PHYSIOLOGICAL ANALYSIS OF HEAT TOLERANCE IN BREAD WHEAT

Abstract

The world population is expected to reach 8.9 billion by 2050. Asia and Africa, where wheat (Triticum aestivum L.) and rice (Oryza sativa L.) are staple crops, will represent 59.1% and 19.8%, respectively, of the world population. This population growth is expected to cause a food crisis. Heat stress is a major abiotic stress factor limiting wheat production not only in the developing countries, but also worldwide. In this regard, identification of superior genotypes that are withstand the high temperature stress, to recommend its cultivation in the areas that are exposed to the high temperature regime, as well as understanding the physiological and genetical mechanisms that control the heat stress tolerance is of relevance. The work in this study was classified into two main experiments, A) Field experiments that were conducted in the Agricultural Experiment and Research Station, Cairo University, and B) Lab experiments that were conducted in the Genetics and Cytology Department, Biotechnology Research Institute, National Research Center, Dokki, Giza, with the following aims: 5- To evaluate twenty wheat genotypes facing high temperature (> 30 oC) during and after anthesis under field condition, in association with pollen grain viability and germinability, to identify the most tolerant and most susceptible genotypes.