Effects of Different Pollination Methods on Fruit Setting of Different Hybrid Combinations in Wild Rhododendron

Rhododendron simsii, R. mariesii and R. ovatum were used as female parents, crossed with R. fortunei, R. simiarum, R. decorum and R. delavayi, and the effects of 6 different pollination methods on fruit setting were studied in order to overcome incompatibility caused by pre-fertilization barriers. The results showed that the best pollination method varied with different combinations. In 6 of 8 combinations, delayed pollination increased the fruit setting rate significantly; pollination after the treatment of 3% salt solution, pollen culture solutionsucrose 50 g/L+H3BO3 10 mg/L+Ca(NO3)24H2O 300 mg/L and pollination of heated pollen promoted fruit setting in some combinations; pollination after the treatment of 0.1% NAA had facilitation just in R. simsii R. simiarum、R. simsii R. delavay and R.ovatum R. simiarum; however, pollination after the treatment of hexane inhibited fruit setting in most combinations.