Milling, processing and end-use quality traits of CIMMYT spring bread wheat germplasm under drought and heat stress

摘要

The CIMMYT wheat breeding program aims to develop bread wheat (Triticum aestivum L.) genotypes that have superior grain yields, disease resistance and stress tolerance, along with appropriate quality to satisfy all stakeholders of the wheat value chain. Grain quality for wheat consists of a combination of many defined parameters including grain morphological characteristics, dough and final products properties, all of which are defined by the genotype, the environment and their interactions. Our current approach for improving grain quality is to study grain samples obtained under high yield potential environments with optimum management. To assess the effect of this strategy on quality under stressed environments, 54 genotypes were evaluated for two years under six environmental conditions, including drought and heat stress. Grain morphology (grain density and size), protein content and flour yield were severely affected by the environment, as drought and heat stress had a strong negative effect on all of these characteristics except protein content. Gluten quality (strength and extensibility) was defined more by the genotype, although the environmental effects and the interactions were also important, particularly for gluten extensibility. The current selection strategy for quality traits carried out under optimum conditions was found to be suitable to ensure high quality characteristics across several environments for most of the parameters with an overall positive outcome.