Emails hanafi@ipk-gatersleben.de; reif@ipk-gatersleben.de

The development of hybrid wheat varieties holds significant promise for enhancing agricultural productivity. Central to this endeavor is a comprehensive understanding of floral biology, which underpins successful hybridization. However, the main bottlenecks are the sluggish selection of complementary parent lines and the high costs of hybrid seed production.

To elucidate the key aspects of floral biology relevant to hybrid wheat production, we tested hybrid seed set of diverse central European elite material using chemical hybridization agent (CHA) and cytoplasm male sterility (CMS) systems pollinated with either elites or plant genetic resources (PGR) in multi-environmental field experiments.

The results showed that female tester lines significantly impacted seed set, with environmental factors playing a prominent role. The observed variation in female effects is partially attributed to inherent differences in pollen-receptivity qualities and overall line performance per se. In contrast, the variability associated with the male tester lines was significantly lower than that observed with the female tester lines.

In the other hand, our findings revealed that elite male lines showed 1.6-fold better seed set compared to plant genetic resources. Nevertheless, male lines substantially reduce adverse effects of PGRs when tested in a hybrid background. The use of CHA-based approach demonstrated a notable advantage over CMS-based approach, resulting in a 1.7-fold improvement in seed set compared to the latter.

This improvement is likely attributed to the full restoration of fertility in the produced hybrids using CHA. However, additional investigations are warranted to validate this observation, emphasizing the importance of deepening our understanding of the genetics underlying female receptivity in hybrid wheat production to optimize seed set efficiency and advance hybrid breeding strategies.