Molecular and phenotypic characterization of drought tolerance in diverse bread wheat ( Triticum aestivum L.) germplasm

Drought limits wheat (Triticum aestivum L.) productivity in arid and semi-arid regions. This study combined phenotypic evaluation with simple sequence repeat (SSR) analysis to characterize 28 wheat genotypes under two irrigation regimes. The stress tolerance index (STI) identified Fawwon 3, Vassa, Velena, Fawwon 6, and Grom as promising genotypes based on joint yield performance across treatments. Of 15 SSR markers screened, 10 were polymorphic. Polymorphism information content (PIC) values ranged from 0.35 to 0.70, averaging 0.51, with Xgwm11 showing high polymorphism. In silico analysis identified putative candidate genes encoding subtilisin-like proteases, peroxidase 3, and proline-rich proteins within selected marker regions. These findings provide preliminary germplasm and candidate-gene resources for wheat improvement. However, limited marker coverage and evaluation at a single location and season necessitate further genomic, functional, and multi-environment validation.