SELECTION OF ALFALFA (Medicago sativa L.) HYBIRD PARENTS AND HETEROSIS ANALYSIS OF F1 HYBRIDS

Heterosis is an effective way to increase yield and improve quality in alfalfa breeding. The key issue for efficiently use of heterosis is to identify parents having potential for producing hybrid combinations with higher performance. This study aimed to analyze genetic distance between the 48 alfalfa accessions, and combine different hybrid combinations. The results showed that the mating ability of the hybrid combination in which both parents are tetraploid is greater than that in which both parents are diploid or the hybrid combination with different parental ploidy. When the different ploidy levels of parents, the mating ability of alfalfa hybrid combination with diploid as female parent is better than that of alfalfa hybrid combination with tetraploid as female parent. he hybrid combination of diploid alfalfa as a female parent with tetraploid as a male parent is more heterosis than the hybrid combination of diploid as a male parent. Moreover, CYK2ｘHH10 with high heterosis and CYK4xHH10 with high the relative seed setting rate should be possible to breed high yielding hybrid, which could be used as candidate materials for further research.