Sequence Analysis Of MatK And ITS Between Malus.Hupehensis And Its Relative Species

Molecular systematics has been invited into the phylogenetic study of plants and widely used on all taxonomic categories with great application potential and theoretical sigingicance.The genus Malus belonging to the Rosaceae family has become an improtant fruit resource in China. Malus hupehensis is a typical allotriploid being considered as a hybrid group. Malus species easily hybridize with each other, hybrids of morphological features vary frequently in nature and among cultivated genotypes, so it is difficult to identify and classify unknown or newly acquired accessions of Malus species by morphological features in nature. Therefore,it is helpful to have information on hybird origion and genetic relationships among these species.Any more,the research is needed for a well understanding of genetic variation and hybird origion in Malus.In present study, we collected100individuals presenting M.hupehensis, M.baccata, M.rockii, M.toringo,M.mandshurica and so on.The joint use of ITS and matK sequences analysis seeks to find the phylogenetic relationships between them and the hybrid origion of M.hupehensis.The main results were as follows:1.Relationship among M.hupehensis and its realtive speciesThe analysis of ITS and matK sequences showed close relationship among M.hupehensis,M.toringo and M.rockii.The samples coming form Zhejiang, Anhui, Jiangxi privences have closer relationship with M.rockii,coming from Shandong, Shanxi prviences have closer relationship with M.toringo and M.baccata.2.Hybrid origins of M.hupehensisThe adductive sites of ITS sequences showed that M.hupehensis derived from hybridization between M.baccata or M.mandshurica and M.rockii or M.toringo.,and existing gene permeation.The difference relationship between various localtions showed that the origion of M.hupehensis maybe multi-point.3.The taxon's positon of some speciesMolecular data dissupport the status of M.baccata var. rockii. Transfer M.toringo to Section baccatae from Section Sorbomalns based on the close relationship between them.The species located on Zhejiang tianmu mountain identified as M.hupehensis variety and named as M hupehensis var. tianmuensis.