Genetic variations, heritability, heat tolerance indices and correlations studies for traits of bread wheat genotypes under high temperature

Abstract

Bread wheat is adapted to many different environments, such as heat-stress conditions. In such areas, heat stress is one of the most important production challenges for wheat. The expected rising global temperature of 1-4°C over the next 50 years will have an effect on the production of wheat in the tropics through heat stress (Hansen, 2006). Heat stress affects more than 30 million hectares of wheat annually in the world and leading to significant grain yield reduction (Battisti and Naylor, 2010). High temperature is reported to decrease yields by 3 to 5 per cent per every 1°C increase above 15°C in plants under controlled conditions (Gibson and Paulsen, 1999). In addition, the effect of climate change is also evident on the quality of wheat, as increased heat results in shriveled wheat grains (Tadesse et al., 2013). To adapt new crop varieties to the future climate, we need to understand how crops respond to elevated temperatures and how tolerance to heat can be improved (Halford, 2009). Success in crop improvement generally depends on the magnitude of genetic variability and the extent to which the desirable characters are important. Germplasm evaluation will be of great significance for selection of heat-tolerant genotypes and for improving grain yield under high temperature. Thus, the objectives of the research were to study the genetic variability, heritability, heat tolerance indices and phenotypic and genotypic correlation studies for traits of 250 elite International Center for Agricultural Research in the Dry Areas (ICARDA) bread wheat genotypes under high temperature in Wad Medani, Sudan