Analysis on the Combining Ability of Main Traits and Heterosis of Diploid Alfalfa

In this study, 3 parts of anthers were used to culture haploid alfalfa and 2 parts of flat alfalfa as parents, and 10 hybrid combinations were combined to analyze the combining ability of 7 major agronomic to explore the relationship between the heterosis of alfalfa and lentil and the general combining ability（GCA）,special combining ability（SCA） and genetic distance of the parents.The results showed that the combining ability analysis found that the internode length was affected by both additive and non-additive effects, and the genetics of plant height, number of internodes, and yield per plant were mainly affected by additive effects.The heterosis of each trait varied greatly among different combinations. In the interspecific hybrid combination of diploid alfalfa and lentil, XJ-3 to CY-5 and CY-35 to HB had suitable effect values of special combining ability for each agronomic traits, strong heterosis, and could be used as an excellent hybrid combination.Studies showed that the SCA and heterosis between combinations could be used to improve the mating efficiency of parents, but the use of SRAP marker genetic distance to predict alfalfa heterosis remained to be further studied.