Identification of drought-tolerant ideotype in wheat using multi-trait genotype-ideotype distance index (MGIDI) and...

Due to the growing impact of climate change, particularly in arid regions, there is a pressing need for high-yield and drought-tolerant wheat (Triticum aestivum L.). Recombinant inbred lines (RILs) from a cross between high-yielding 'SeriM82' and drought-tolerant 'Babax' offer a valuable genetic resource. This study evaluated 167 RILs along with their two parents under two irrigation regimes over 2 years to identify optimal genotypes using morpho-physiological traits, principal component analysis (PCA), drought indices, comprehensive evaluation value (D), drought resistance index (DRI), and multi-trait genotype-ideotype distance index (MGIDI). Drought stress significantly reduced all studied traits, with chlorophyll concentration (SPAD), relative water content (RWC), and grain yield (GY) most affected. The population showed high genetic diversity. RWC was strongly positively correlated with biological yield (BY) and GY. GY under drought exhibited a strong positive relationship with the stress tolerance index (STI; r = 0.96). Based on PCA and D values, RILs 76, 104, and 144 demonstrated superior performance under drought. Cluster analysis categorized RILs into five groups; one cluster showed high relative stress index and STI, indicating high drought tolerance. In MGIDI analysis, STI had a higher selection differentials percentage. Based on combined MGIDI rankings and DRI, RILs 21, 23, 25, 48, 54, 64, 70, 77, 90, 139, 149, and 162 were identified as the most drought-tolerant. The results demonstrate that integrating DRI and MGIDI provides a rapid, cost-effective method for selecting high-yielding wheat genotypes with resilience across varying water conditions, facilitating accelerated breeding for climate resilience.