Predicting genetic gains for multi-trait selection in durum wheat under semiarid conditions

Abstract

The objective of this work was to evaluate the effectiveness of seven selection indices combined with different economic weights in improving agronomic traits in durum wheat. The experiment was carried out at the agricultural experimental station of Institut Technique des Grandes Cultures in Sétif, Algeria, during the 2022/2023 cropping season. A total of 59 genotypes were evaluated in a randomized complete block design with three replicates. A significant genetic variability was observed, with a high broad-sense heritability for days to heading, plant height, chlorophyll content, and straw yield, indicating a strong potential for selection. The Mulamba & Mock index combined with the variation index and heritability effectively reduced days to heading and increased chlorophyll content. The Cruz index weighted by heritability was the most effective for flag leaf area, while the Cruz and Smith & Hazel indices combined with the variation index improved plant height. For yield traits, including grain yield and spike weight, the Smith & Hazel, Mulamba & Mock, and Pesek & Baker indices led to the highest gains when weighted by standard deviation and the genotypic coefficient of variation. Biomass traits, such as straw yield and aboveground biomass, are best improved by the Smith & Hazel and Williams indices, particularly combined with the variation index. The coincidence analysis shows a strong agreement among selection strategies, identifying superior genotypes for semiarid environments.