论文标题:应用分子标记技术研究玉米与其主要野生近缘种的遗传关系及取样策略
Analysis of Genetic Relationships between Maize and Its Wild Relatives and Identification of Sampling Strategies Using Molecular Markers
论文作者 田松杰
论文导师 王天宇；黎裕,论文学位 硕士,论文专业 作物遗传育种
论文单位 中国农业科学院,点击次数 1344,论文页数 72页File Size3170k
2003-06-01论文网 http://www.lw23.com/lunwen_60707/ 玉米;野生近缘种;AFLP;SSR取样
Maize;AFLP;SSR;Wild relatives;Sampling
研究栽培作物与其近缘野生种的遗传关系，集约合适的群体取样数量不仅对研究作物遗传多样性，收集、保存和利用品种资源十分重要，在转基因植物安全性评估中，也是检测转基因作物目的基因漂移及评估其所产生生态效应的基础，本研究工作主要以玉米为研究对象，重点利用分子检测技术探讨我国的代表性的玉米种质资源与收集到的玉米近缘野生种的遗传关系。在此基础上，研究玉米群体取样数量的合适度，旨在为今后玉米资源的收集保护、发掘利用等深入研究提供依据。主要结果如下： 1、利用AFLP分子标记技术对50个有代表性的玉米及其野生近缘种大刍草、摩擦禾、薏苡材料进行了遗传关系分析。结果表明21个PstI／MseI引物组合检出可辨认带共641条，其中具多态性带586条，平均每对引物得到30.52条多态性带，多态性91.4％。UPGMA聚类分析结果表明，可以将50个材料分为三大类，与已有的对玉米族的分类相一致，但与玉蜀黍属属内的种间和种内分类并不太一致，说明大刍草各种内存在较高的遗传多样性。本实验结果发现玉蜀黍属与摩擦禾关系比与薏苡的关系更近，但并没有发现玉米与小颖玉米亚种比与其它大刍草的遗传关系更近。 2、利用SSR分子标记术对两个玉米地方品种：矮粘、番早苞谷和一个玉米育种群体材料91at665和利用AFLP分子标记技术对其中的育种群体91at665进行玉米遗传多样性分析时的取样量研究。用混合样和单株分析不同遗传结构群体对取样量的影响。结果发现从10个到100个单株的混合样间和相同混合量不同个体组成的混合样间的差别都不大，特别是在遗传多样性低的育种群体91at665中。但对于玉米群体需根据群体遗传多样性和实验目的适当取样和使用适当数目的个体混合进行实验。研究表明，遗传多样性低的玉米群体，10个，最多20个个体组成的混合样可基本代表群体遗传特征，可以用于一般研究；在遗传多样性高的玉米群体中，30个，最多40个个体组成的混合样可基本代表群体遗传特征；多个较少个体组成的混合样在进行玉米遗传多样性和遗传变异研究时是最有效的措施。
Analyses of genetic relationsips between maize and its wild relatives and determination of sampling strategies of genetic diversity assessment is of great importance for studies on genetic variation, collection, preservation and utilization of genetic resources, and detection of gene flow and assessment of ecological effects of transgenic maize. The present study focused on the analysis of genetic relationships between maize and its wild relatives and sampling strategies of genetic diversity assessment of maize populations (including landraces and breeding populations), in order to provide the basis of collection, preservation and utilization of maize germplasm.The major results are as follows.1. AFLP marker technique was used to investigate the genetic relationships between maize and its wild relatives including teosintes, Tripsacum and Coix. Twenty-one AFLP primer combinations of PstlI/Msel were used in the study and 641 AFLP amplified bands were obtained, including 586 polymorphic bands with an average of 30.52 per primer combination. The polymorphism percentage was 91.4%. The cluster analysis using UPGMA method based on the data of AFLP showed that the 50 materials could be divided into three groups (Tripsacum, Zea and Coix), which agreed with the former taxonomical classification. But the groupings under Zea were not consistent with the taxonomy. The present study confirmed that maize had closer relationships with Tripsacum than with Coix, but did not find the evidence to support the closer relationships between maize and Zea mays ssp. parviglumis.2. AFLP and SSR markers were used to investigate the genetic structure of three maize populations (two landraces and one breeding population), and to identify the effects of genetic structure on sampling of maize populations. There were fewer differences among the bulks with different number of individuals or the same number of different individuals. The optimal sample size was 10-20 individuals per bulk for the groups with lower genetic diversity, and 30-40 for the higher. Using several bulks with fewer individuals is an appropriate strategy to assess genetic diversity or genetic variability.
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