Interspecific Hybridization Between Species of Actinidia L. and Breeding of Superior Selection
Fan Peige, An Hexiang, Cai Darong, and Mu Xijin (Insitute of Botany,The Chinese Academy of Sciences,Beijing 100093 China)
The study deals with investigation of interspecific hybridization between Actinidia deliciosa cv. Hayward (2n=6x=174) and A.eriantha (2n=2x=58) for breeding superior selections. 26 hybrid seedlings had been obtained through hybridization and cultivation for many years. The main results obtained were: 1) The interspecific hybridization, A. deliciosa cv.Hayward x A. eriantha appeared to be some degree of compatibility based on its rate of fructification (53.3%) and normal seeds (53.9%); 2) Although the general morphological characters of all the hybrid seedlings appeared to be intermediate type, i.e.,between paternal and maternal type,however,the individual characters of some hybrid seedlings tended to paternal side, such as leave shape and fruit size,or others maternal,such as flower colour; 3) The noticeable divergence in hybrid seedlings was the flower colour. In all the female hybrid seedlings, the flowers were white in colour, the same as that of maternal, but in all the male hybrid seedlings, the flower colour was divided into three kinds: white flowers; red flowers (the same as that of A. eriantha) and peach-white flowers ( in which the periphery of petal was white colour, while the inside of petal periphery was peach colour). A superior female plant,hybrid seedling Ⅲ-6,had been selected from the hybrid seedlings obtained by embryo rescue method. The chromosome ploidy in hybrid Ⅲ-6 was near tetraploid and isoperoxidase banding patterns of it appeared to be intermediate type, i.e. between paternal and maternal type. The commercial characteristics of hybrid Ⅲ-6 fruits were superior and genetically stable through many years of experimental observation. In addition, the relationship between the ploidy levels of cross parents and the success or failure of interspecific cross in the genus Actinidia was discussed.