杜鹃花属映山红、马银花与羊踯躅三亚属间杂交亲和性研究OA北大核心CSTPCD

Rhododendron resources are abundant in China and have a long history of cultivation.Hybridization breeding technology can greatly enrich Rhododendron resources.Rhododendron subgen.Tsutsusi,subgen.Azaleastrum and subgen.Pentanthera belong to the same evolutionary branch of hairy Rhododendron.In order to explore the compatibility of hybridization and the stages of hybridization barriers among 3 genus,Rhododendron simsii,R.pulchrum and 8 cultivars of subgen.Tsutsusi,R.ovatum of subgen.Azaleastrum,R.molle and 2 cultivars of subgen.Pentanthera were studied.The cross compatibility between subgenera was analyzed from the aspects of style length ratio,pollen germination,pollen tube growth,ovary and embryo development.The results showed that there was obvious prezygotic unidirectional discompatibility among subgen.Tsutsusi,subgen.Azaleastrum and subgen.Pentanthera.All pollen combinations could germinate in large quantities in stigma.The pollen tubes of subgen.Tsutsusi×subgen.Pentanthera,subgen.Azaleastrum×subgen.Pentanthera,and subgen.Azaleastrum×subgen.Tsutsusi reached the base of the style in large numbers and were able to set fruit.Reciprocal cross pollen tubes mostly stop growing in the middle of the style,a few reach the base of the style,and could not set fruit.The embryo development of subgen.Azaleastrum×subgen.Pentanthera and subgen.Azaleastrum×subgen.Tsutsusi were slower than that of subgen.Tsutsusi×subgen.Pentanthera,and the capsule dehiscent time was also late,most embryos of mature seeds in each hybridization direction were incomplete.The results of compatibility experiments showed that the cross barriers appeared in pollen tube growth,double fertilization and embryo development.The present study explored the law of cross compatibility and could provide reference for cross breeding of Rhododendron subgenera.