Agro-physiological traits for enhancing grain yield in rainfed durum wheat

Abstract

Understanding the physiological traits enhancing grain yield is important for wheat breeding under rainfed conditions. Nineteen durum wheat genotypes differing in origin were evaluated for their grain yield and agro-physiological characteristics under rainfed conditions for two consecutive cropping seasons,2017-18 and 2018-19. The main effects due to year, genotype and their interactions were significant for most of the investigated traits. The genotype by trait biplots (known as GT biplot) indicated that the relationships among the studied traits were not consistent over the years but they facilitated visual genotype comparison and selection at each year. The 1000-kernel weight (TKW) and normalized difference vegetative index (NDVI) consistently associated with grain yield suggesting the importance of these traits to be used as selection criteria for enhancing grain yield under rainfed conditions. Based on the cluster heat map, the genotypes classified into five groups with different levels of combined grain yield and physiological and agronomic attributes. The traits heading date, NDVI, Fv/Fm, TKW and SPAD-reading had contributed to grain yield. The study also identified potential lines with high yield and drought tolerance for subsequent varietal development for water limited areas.