Phenotypic selection of high-yielding, water-productive wheat (Triticum aestivum L.) putative mutants under well-watered and limited-irrigation conditions

Abstract

Developing high-yielding and water-stress-tolerant bread wheat cultivars with high water productivity is vital for sustainable wheat cultivation under the limited water resources in Egypt. In this study, bread wheat mutant lines from the M3, M4, and M5 generations and their mother cultivars were evaluated under both well-watered and limited-irrigation conditions over three growing seasons (2022–2024). Eight agronomic traits and water productivity were estimated to detect high-yielding, water stress-tolerant wheat lines with improved water productivity. Significant differences (p ≤ 0.05) were observed among the mutant lines for the studied traits under both conditions. Twelve selected mutant lines surpassed their mother cultivars. Mutant line G5 exhibited the shortest plant height with high potential yield, representing a dwarf phenotype. Mutant lines G10, G1, G2 and G4 exhibited the highest actual genetic gain relative to the highest-yielding mother cultivar. High broad-sense heritability coupled with moderate to high genetic advance for the studied traits indicated the predominance of additive gene action and confirmed the effectiveness of phenotypic selection. Drought tolerance indices selected the same promising lines under limited-irrigation conditions. GGE biplot analysis revealed that mutant lines G2, G3, G4, G5 and G6 were superior high-yielding lines, whereas G4, G7, G10 and G11 exhibited greater stability across irrigation regimes. Selected mutant lines exhibited improved water productivity compared with their mother cultivar under both conditions. Selected putative mutant lines will be advanced to multi-environment trials to further evaluate genotype x environment interactions and genetic stability. These mutant lines could serve as valuable genetic resources for bread wheat breeding programs aimed at enhancing grain yield under water-limited conditions.