Primary Study on Hybridization Breeding among Several Rhododendron Species in Yunnan Province

For exploring the rule of Rhododendron breeding and accelerate the progress of domestic Rhododendron breeding, we studied the compatibi lity, fruit setting rate, the relationship between hybrid seeds weight and seeds germinate rate of several Rhdodendron species, through the experiment of twenty-two artificial hybrid combinations of Rhododendron fortunei Lindl, R. decorum Franch, R. irroratum Franch, R. aberconwayi Cowan, R. simsii Planch, R. molle (Blum) G. Don. The results showed that R.fortunei had preferable affinity when it served as both male parent and female parent, fruit setting rates reached 21%~75%, seeds germination rates accounted 41%~88%, and the affinity of R. decorum came the second, fruit setting rates reached 3%~66%, seeds germination rates accounted 76%~82%. The fruit setting rates of the artificial hybrid combinations depended on the female parents. The seeds weight was more important for germination, but the germinating process was influenced by the environment factors and the vitality of embryos. It is important significance for the Rhododendron breeding. Both R. fortunei and R.. decorum have good comprehensive characters and could be excellent parents for evergreen Rhododendron breeding.