【作者】 丁芳兵；

【导师】 汤庚国； 钱关泽；

【作者基本信息】 南京林业大学 ， 植物学， 2012， 博士

【摘要】 植物分子系统学已广泛地应用于植物系统学研究的各级分类单元上，体现出了一定的应用前景和理论意义。苹果属（MalusMill）植物是我国一种重要的果树资源，其中湖北海棠（Malushupehensis）为典型的异源三倍体（2n=3X=51）种，公认为是一个杂种类群，种间普遍存在连续的变异类型，基于传统形态学分类方法很难进行种的确切判断和种间系统关系的分析。因此研究该属杂交类群的起源和种间遗传关系不仅有助于阐明该属植物系统演化和物种成机制，而且对杂交选育和开发利用也具有重要意义。本研究选取湖北海棠、山荆子、丽江山荆子、三叶海棠、毛山荆子等共100多份材料，通过分析nrDNAITS序列和cpDNAmatK序列，基本弄清了湖北海棠及其近缘种间的亲缘关系和杂交起源方式，主要研究结果如下：1.关于湖北海棠及其近缘种的亲缘关系ITS和matK序列分析表明湖北海棠与丽江山荆子和三叶海棠有较近的亲缘关系，其中浙江、安徽、江西等地区的湖北海棠与丽江山荆子亲缘关系较近，山东、陕西等地的湖北海棠与三叶海棠和山荆子亲缘关系较近。2.关于湖北海棠的杂交起源问题ITS序列加合位点显示湖北海棠起源与山荆子或毛山荆子与三叶海棠或丽江山荆子的杂交，并且存在基因渗透现象。不同地区种间亲缘关系差异显示湖北海棠可能为多点起源。3.一些苹果属种的分类地位的变更本研究不支持丽江山荆子作为变种的地位，恢复作为一个独立的种；鉴于三叶海棠和山荆子组有较近的亲缘关系，支持将三叶海棠从花楸组中移入山荆子组中；天目山仙人顶存疑种鉴定为湖北海棠的变种，确定为一新变种天目山海棠（Malushupehensisvar.tianmuensis）。更多还原

【Abstract】 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.更多还原