Variation of floret fertility in hexaploid wheat revealed by tiller removal

Grain number per spike, which is greatly influenced by floret fertility, is an important trait of wheat (Triticum aestivum L.) yield. Maximum floret primordia, fertile floret, and final grain number per spikelet are three crucial factors of floret fertility. Floral degradation plays a critical role in determining these three floret fertility-related traits. Twelve hexaploid spring wheat genotypes were selected to investigate the influence of detillering on floral degradation and floret fertility-related traits in the field and greenhouse. Notably, the green anther stage was found to consistently have the maximum floret primordia number. Visible floral degradation, however, was observed to occur at several floral developmental stages, specifically from green anther stage to anthesis. Detillering was able to delay floral degradation in most cases and was evidently highly associated with increased maximum floret primordia, fertile floret, and final grain number per spikelet, with only a few exceptions. Thermal time required for each floral developmental stage was overall not influenced by detillering. These data hereby reveal a predominant spikelet fertility pattern along the spike in which the number of fertile florets per spikelet at anthesis becomes developmentally confined.