Preliminary Investigation Of Heterotic Group Established By Using Recurrent Selection In Wheat (Triticum Aestivum L.)

Recurrent selection has been broadly used for crop improvement in many crops. Fifteen wheat lines have been selected from 15 recurrent selection populations using the Tal male sterility. The agronomic traits performances of the 15 wheat lines and 5 wheat elite lines, together with the hybrid vigors between the two groups, were tested for three years in Beijing. The genetic distances (GD) between the two groups were determined by SSR and EST-SSR markers in order to evaluate the effects of creating new heterotic groups by recurrent selection. The main results obtained are as follows:1. The performances of seven agronimic traits on 15 recurrent selection lines and 5 wheat elite varieties showed distinct difference between the two groups. The recurrent selection lines and the wheat elite lines were grouped into two clusters.2. Higher yield per plant was observed on hybrids between the recurrent selection lines and the wheat elite lines than that of hybrids between wheat elite lines after testing 75 hybridized combinations (NCII design) between the 15 recurrent selection lines and 5 common wheat elite varieties, indicating potential use of recurrent selection on constructing wheat heterotic group.3. Cluster analysis results based on SSR and EST-SSR markers revealed that the 15 recurrent selection lines and 5 wheat elite varieties could be assigned to distinct groups, suggesting the SSR markers was a useful tool for assigning heterotic group. However, no significant correlations between the SSR GD and the F1 heterosis performance and SCA were observed indicating the limitation of using SSR GD to predict wheat heterosis in breeding program.