Integrating SSR Markers and Generation Mean Analysis for the Detection of Yr Genes in Two Bread Wheat Crosses

The inheritance of yield and its contributing traits was studied utilizing generation mean analysis across six populations (parents, F1, F2, and backcrosses) from two bread wheat crosses (Misr 1 x Yr8 and Misr 1 x Yr15) over three seasons (2020/2021 to 2022/2023) at Sakha Agricultural Research Station, Agricultural Research Center, Egypt. The results showed that all traits were quantitatively inherited, with dominant effects usually stronger than additive ones. The only characteristics that weren't quantitatively inherited were spike length, number of spikes per plant, and grain yield in cross-one. Broad-sense heritability values varied from moderate to high, indicating significant heritable variation, while narrow-sense heritability was low for most traits, making selection challenging for traits heavily influenced by the environment. Grain yield in cross 1 showed moderate genetic advance (32.44%), suggesting effective early-generation selection. Genotypes clustered by genetic background, with Yr15 and BC1 in cross 2 identified as promising candidates for breeding due to valuable alleles for traits like kernel weight and spike length.