Seed germination and seedling growth of spring bread wheat recombinant inbred lines (RILs) under PEG-induced drought stress

Abstract Wheat is one of the staple foods, and its importance is considerable on a global scale. Drought stress significantly affects wheat seed germination. The absence of drought-resistant wheat varieties affects wheat cultivation, especially in arid regions of the world. This study examined seed germination and seedling growth of 147 wheat genotypes subjected to moisture stress induced by polyethylene glycol (PEG). All studied traits showed significant reduction in stress environment in comparison to control (PEG-0%), while MGT and RSR showed increase under stressful condition. The genotype (G), PEG-Treatments (TPEG), and G × TPEG(T PEG ), and the G × T PEG interactions had significant effects on all studied traits ( p < 0.01), implying considerable variation of genes among the RILs. PCA and cluster analysis revealed a good distinction between tolerant and susceptible genotypes. Elite RILs retained their high SVI, RL, and SHL even in severe osmotic stress conditions, which is a great opportunity for use of those lines in the development of drought tolerant varieties through breeding programs. Nevertheless, PEG osmotic stress is not similar to field drought conditions, and thus the results obtained are indicative of osmotic stress response only. The described genotypic variation represents a very good basis for further QTL and marker-assisted breeding work for improved drought resistance in bread wheat.