Wheat breeding has significantly contributed to enhancing yield potential and stability. However, one of the most promising technologies for further sustainable yield increases, hybrid wheat, is still limited due to lack of well-established heterotic groups and insufficient heterosis to compensate hybrid seed production cost. Thus, maximizing heterosis and optimizing floral and flowering traits to increase seed production are major objectives for an efficient hybrid wheat breeding program. The aim of the present study was to study the existing variability for floral and flowering traits in a collection of 400 genotypes mainly elites from ICARDA breeding program, commercial checks and synthetic derivatives under controlled conditions. The results under controlled conditions were then re-tested in two field trials with a subset of 200 genotypes with best performance for some of the evaluated traits (anther length, anther extrusion, pollen mass, stigma length, degree and duration of floret opening).

A clear genotypic variation for all the traits assessed was observed. Genotype and environment were highly significant for all the variables. The synthetic derivative genotypes showed longer anthers but less pollen mass as compared to the rest. The evaluated floral traits showed a wide phenotypic range: 8.48-79.64%, 3.26-4.45mm, 19.47-100.41min, 12.9138.85°, 5.91-41.98mg and 2.51-4.34mm for anther extrusion, anther length, duration of floral opening, openness of the floret, pollen mass and stigma length, respectively. Anther extrusion was highly correlated with pollen mass, floral openness and duration of floral opening (r=0.768, p=0.001; r=0.706, p=0.001; r=0.636, p=0.001 respectively). Similarly, pollen mass was strongly correlated with duration of floral opening and openness of the floret (r=0.809, p=0.001) and (r=0.838, p=0.001), respectively. No clear correlation was found between anther extrusion and anther and stigma length which means these traits have to be selected independently. All desired floral traits are positively correlated meaning the easy-to-score trait can be taken as proxy. The large genotypic variance for most of the studied traits suggest that there is a great potential to enhance out-crossing efficiency in spring wheat improving thereby hybrid seed production.