Genetic Analysis of Seed Set in Wheat ( Triticum aestivum L.) Hybrids Generated With Cytoplasmic Male Sterility Versus Chemical Hybridization Agents

The main challenge in hybrid wheat breeding is the low efficiency of hybrid seed production due to wheat's self‐pollinating nature. Efforts to improve cross‐pollination have mainly focused on enhancing pollen donor performance or increasing seed set in hybrids generated using chemical hybridization agents (CHA). Starting with 100 diverse wheat elite lines, this study compared hybrid seed set under CHA and cytoplasmic male sterility (CMS) systems for a subset of 26 lines, pollinated by a pollen donor mixture in multi‐environment field trials. Seed set, expressed as grain yield (g m −2 ) of the seed parent, exhibited heritabilities of 0.40 (CHA) and 0.59 (CMS). The CMS system showed a 1.5‐fold genotypic range, whereas the CHA system spanned 2.5‐fold. On average, CMS seed set was 13% lower, and the genetic correlation between systems was moderate ( = 0.45), suggesting that CHA‐based seed set has limited predictive value for CMS performance. Per se grain yield did not predict hybrid seed set, highlighting the need for indirect traits and genomic tools to refine CHA‐based preselection before CMS conversion.