摘要： 利用RAPD分子标记技术，对我国目前25个主要玉米自交系进行亲缘关系类群划分。本项研究建立了从玉米种子、幼芽以及叶片组织中提取微量DNA的方法。从RAPD引物试验盒A至O共计300个引物中，筛选出对玉米扩增产物具有多态性的引物40个，其中具有特别明显多态性的引物10个。它们是F₃、O₂₀、A₁₉、M₂、M₆、N₁₁、N₁₂、N₁₉、C₇和G₁₄等。依据10个引物扩增谱带建立0，1型数据，计算25个自交系间遗传距离，并进行聚类分析。结果表明：供试的25个自交系共可划分为5个类群。Ⅰ类为四平头血缘系统：包括黄早四、吉853、黄野四、四自四、196、81515、404、H21等共8个；Ⅱ类为瑞德黄马齿血缘系统：包括478、488、3189、7922、8112、B尖8、5005等共7个自交系：Ⅲ类为兰卡斯特血缘系统：包括Mo17、早49、多22等共3个；Ⅳ类为旅大红骨血缘系统：只有E28一个自交系；Ⅴ类共有P78、9502、178、P138、007、P17等6个自交系。这一类群都是由杂交种P78599后代选系而来，与美国另外两个类群瑞德黄马齿系统和兰卡斯特系统关系较远，它们之间选配的杂交组合大多具有较强的杂交优势。这一类群的自交系在我国玉米育种和生产上的应用将进一步扩大。研究结果表明：用RAPD分子标记进行玉米自交系类群划分与系谱法相吻合。通过不同自交系之间杂交，其产量杂交优势的表现，也验证了应用RAPD标记划分的5个不同亲缘关系类群的正确性。

关键词: RAPD, 玉米, 类群划分

Abstract: Heterotic groups were classified by cluster analysis with RAPDs based on 25 important maize inbreds utilised widely in hybrid maize production in China. Ten primers: F₃, O₂₀, A₁₉, M₂, M₆, N₁₁, N₁₂, N₁₉, C₇ and G₁₄, selected from 300 candidate primers from the operon A, to O₃ were used as polymorphic DNA (RAPD) markers for 25 maize inbred lines. Genetic distance among 25 inbreds was calculated and clustered with RAPD markers. The results showed that 25 inbreds lines could be classified into five groups. Groups I consisting of Huangzao 4, 853, Huangye 4, Sizi4, 196, 81515, 404, H21 is included in the Sipingtou heterotic group. Group Ⅱ consisting of 478, 488, 3189, 7922, 8112, Bijian 8, and 5005, is included in the Reid heterotic group. Group Ⅲ consisting of Mo17, Zao 49, and Duo 22, belong to the Lancaster heterotic group. Group Ⅳ only consisting of E28, belongs to the Lda Honggu heterotic group. Group V consists of P78, 9502, 178, P138, 007, and P17. They belong to a new heterotic group different from the above four heterortic groups. The five groups by cluster analysis with RAPD markers conforms to the pedigree method. The results of the study indicated that it is practical to group maize inbred line with RAPDs.

Key words: Maize inbred, RAPD, Heterotic group, Cluster analysis