Hybrid grain production in wheat benefits from synchronized flowering and high female flower receptivity.

This article focuses on the factors influencing hybrid grain production in bread wheat (Triticum aestivum L.), particularly the role of synchronized flowering and female floral receptivity. Through multi-year field and greenhouse experiments with elite wheat lines, the study found that optimal synchronization of flowering between male (pollen donor) and female (male-sterile) lines positively affects hybrid grain set, but does not guarantee high yields due to inherent genotypic differences in female floral receptivity. The authors developed an extended Waddington scale (W+) to phenotype the "second opening" phase of male-sterile florets, revealing that a longer duration of this phase correlates with increased hybrid grain set. Environmental factors such as heat and drought also impact flowering traits and grain yields, yet stable genotypic differences in female receptivity persist across conditions, highlighting the importance of selecting female lines with prolonged floral receptivity for efficient hybrid wheat production.