【作者】 邓洪平；

【导师】 成明昊； 周志钦；

【作者基本信息】 西南农业大学 ， 果树学， 2002， 博士

【摘要】 苹果属(Malus Miller)系蔷薇科(Rosaceae)苹果亚科(Maloidae)植物。全属植物世界公认的有30—35种，主要分布于亚洲、欧洲和北美洲。中国至少有23种，如果加上近年发表的8个新种，则种类数目达31个，主要分布在除海南省以外的全国30个省、市和自治区，尤其以中国的云南、贵州、四川、甘肃和陕西等分布种类较多；其中分布种类占前3位的省分别是四川、云南和陕西，拥有种的数目分别为24种、17种和15种。在所有种类中，分布最广的种是湖北海棠，达18个省、市和自治区。其次是三叶海棠，分布于16个省。在我国，苹果属植物不同种类分布的生境差异极大，生长的海拔范围差异近4000米，能生长在各种不同类型的土壤上，甚至沙漠、盐碱地到悬崖峭壁上都能生长。 在过去的几十年中，我国的苹果资源研究工作者对苹果属植物的种类、数量、分布、形态学、系统学、孢粉学、细胞学、生殖生物学和抗逆境生物学特性等众多方面开展了广泛、系统和深入细致的研究，取得了许多重要成果，但也存在明显不足。首先，在研究方向上，基础研究和应用研究明显脱节，并且缺乏重点。对于象变叶海棠等珍贵的苹果基因资源，由于缺乏资金投入，研究有待进一步系统和深入；其次，资源研究的技术和手段不够先进，传统的田间保存技术也由于资金短缺和条件限制，现保存资源的损失与日俱增，许多珍贵的基因资源得而复失。利用现代生物技术的各种先进手段开展对苹果资源的保存、优质基因的鉴定和利用等方面的研究几乎是空白。另外，生物多样性是当今研究的热点，其主要包括 物种多样性。遗传多样性和生态环境多样性、景观多样性和人文多样性等 几个方面，而苹果属植物物种多样性的研究比较多，但种内的多样性及其 类型分化的研究少有报道，对于形态和遗传物质多样性都相当丰富的变叶 海棠更是如此。在变叶海棠的主要分布区内，有陇东海棠和花叶海棠（或 其中之一）的零星分布，它们在四川西部和甘肃南部汇集，表现为地理亲 缘；其分布区的分异表现为地理替代，该地区植物区系成分新老兼备。现 有研究表明，变叶海棠分布面积较广，海拔高度差异较大，微生境极其复 杂多样。变叶海棠根系发达，能穿透坚硬的土层和岩石裂缝，它具有喜光 耐旱的特点，在阳坡、凸坡、悬崖峭壁、瘠薄坚硬的石谷子地、道路两旁 和农耕地边都能正常生长，与花叶海棠近似；变叶海棠也具有喜湿耐阴的 特点，在深山峡谷、甚至在根系长期经受洪水侵袭的溪边、河岸也能正常 生长，与陇东海棠近似。该物种形态变异的类型复杂，具有一系列从陇东 海棠到花叶海棠之间的变异类型。在种质特性方面也呈现出多样性，各形 态类型间耐旱性、耐涝性、耐盐性、耐热性、抗根腐病和抗苹果腐烂病等 均表现出明显的差异，也是苹果属植物中具有多种高抗性的种类，是极重 要的苹果种质资源。变叶海棠与苹果品种嫁接亲和性好，嫁接树具有矮化、 提早结果、果实品质好等优良性状，是优良的苹果砧木。但目前有关变叶 海棠众多优良特性的分子基础、种群的遗传结构和遗传多样性等问题都少 有研究报道，从而极大地限制了资源的开发和利用。因此，本论文选择变 叶海棠为研究材料，利用区系地理学、数量分类学和现代分子生物学技术， 将研究的重点放在变叶海棠遗传多样性的起源、与替代种的亲缘关系等方 面，期望通过本论文的研究，能为利用现代分子生物学技术结合传统的育 种技术研究和开发利用我国宝贵的苹果基因资源探索新的研究途径，也为 我国苹果产业的新发展提供新思路。 采用传统的数量分析方法，结合AFLP分子标记技术和Anderson设计 的“形象化散点图”法、“杂种指数”法、常规聚类分析手段（主成分、 主因子、欧氏距离和图论聚类）及NTSYS－PC等计算机分析软件，开展了 变叶海棠的多样性现状、渗入杂交机理、遗传多样性分析、多样性类型的 AFLP分子系谱等的分析和研究，得到了如下结论： 2＊）．变叶海棠存在着丰富的遗传多样性。 采用各种遗传分析方法表明：变叶海棠无论是类群水平，还是个体水平，均呈现出种内存在着丰富的遗传多样性。这些遗传多样性表现在各实验群体中存在着一系列的介于花叶海棠和陇东海棠之间的多样性类型。p）．变叶海棠遗传多样性的起源 通过AFLP指纹图谱分析表明，在各变叶海棠多样性类型中，其谱带类型、各带型分布特点、遗传距离、基因频率、遗传相似性等均介于变叶海棠与陇东海棠之间。本实验所取变叶海棠材料的多样性分化类型而与变叶海棠和陇东海棠的人工杂交后代植株进行比更多还原

【Abstract】 Malus Miller, belongs to sub-family Maloidae of Rosaceae in plant taxonomy. There are thirty to thirty-five recognized species of this genus in the world, which are mainly distributed in Asia, Europe and North America. Among them twenty to twenty-three, were found in China. If the eight new species published in recent years were included, there are thirty-one Malus species in China. They cover geographically all the twenty-nine provinces, municipalities and autonomous regions of china with one of exception of Hainan Province. The most densely populated areas are Sichuan > Yunnan and Shanxi Province, Which have 24, 17 and 15 species respectively. The most widespread species is Malus hupehensis(Pamp.) Rehd., whose distribution covers 17 Provinces, municoplalities and autonomous regions. The next is Malus setok Vass., whose distribution covers 15 provinces. The altitude variation of the distribution of the different Malus species in China reaches nearly 4000 meters, and they grow on various types of soil, even on desert, alkaline soil and on overhanging rocks and steep cliffs.In the past several decades, all kinds of research work have been carried out on the genetic resources of genus Malus species. Therefore, much progress has been made concerning the studies of the number of species, geographical distribution, morphology, classification, cytology, cell biology, reproductive biology and resistance characters to various environmental stresses. There are, however, many problems which need to be solved in the future work. For example, concerning the subjects of researches we’ve ignored grently the connection between the basic researches andapplication study. In-depth researches on the rare gene materials such as Mains toringoides are badly needed. The researches on genetic materials conservation, identification and utilization of the apple resources using the modern molecular technology are almost a blank. Biodiversity in addition has become a hot point of recent study. Many researches on species diversity of Mains Millerwere reported, the studies on genetic diversity were rarely reported, especially for the species such as Malus toringoides Hughes, which is rich in morphological and genetic diversity. In the main area populated by Malus toringoides Hughes, Malus kansuensis and (or) Malus transitoria were found occasionally. The fact of the three species’ convergence in Western Sichuan and Southern Gansu shows their close relation-ships geographically. Their different distribution indicate their geographical replacements, of subflora forest vegetation of China-Himalayas,in which many new and old species co-existed.The existing experimental results show that Malus toringoides distributed widely in different area which has great altitude variation and complicated microhabitats. The root system of Malus toringoides is so developed that it can grow on prior soil and in cracks of rock. Like Malus transitoria, Malus toringoides tolerant to draught and can grow on sunny dry slope, rocks of steep cliffs, barren stone area, roadsides and field sides. Malus toringoides was also adapted to habitat shade and can grow normally gorges of hill, and even on sides of brook and river, where water often attack on. These characters are similar to Malus kansuensis. In addition, M. toringoides has complex morphological variation and a series of variants were found between Malus kansuensis and Mains transitoria. Furthermore, it has features of asexual apomixia and a good grafting affinity to many cultivars with effects of dwarfing, early fruiting and fruit quality improving on the grafted trees. So it can be a perfect apple rootstock in terms of its overall characteristics. Concerning M. toringoides there are, however, many questions, such as the molecular basis of its excellentcharacters, the genetic structure and diversity of its populations, still needed to be answered. Therefore, in this thesis the M. toringoides were selected as experimental materials. Using the metheds of flora geography N numerical taxonomy更多还原