玉蜀黍属物种间遗传关系的RAPD分析

Genetic relationship analysis of Zea species using RAPD markers

用136个RAPD引物对玉蜀黍属大刍草和玉米种质基因组DNA的多态性进行检测，共得到5303条条带，其中多态性带4500条。遗传相似系数分析结果表明，玉米与大刍草种质遗传相似性系数变幅为0．585～0．809，相同种遗传相似性系数为0．767-0．809，而种间或亚种问的相似性系数为0．585～0．745，表明利用RAPD技术能准确地揭示出玉米与大刍草种间的遗传关系。聚类结果表明，玉蜀黍属内所有大刍草和玉米可分类为繁茂亚属和玉蜀黍亚属，繁茂亚属包括四倍体多年生类玉米种、二倍体多年生类玉米种、繁茂类玉米种和尼加拉瓜类玉米种；玉蜀黍亚属包括小颖类玉米亚种、墨西哥类玉米亚种、委委特南戈类玉米亚种和玉米。运用RAPD技术证实在玉蜀黍属中尼加拉瓜类玉米种与繁茂类玉米种亲缘关系最近。

Randomly amplified polymorphic DNA （RAPD） was used to identify the polymorphisms and relationships between 14 genotypes of maize and its wild relatives （teosinte）. A total of 136 primers were screened from 340 random decamer primers, and a total of 5 303 DNA bands were amplified, of which 4 500 were polymorphic. Genetic similarities among the cultivars ranged from 0. 570 to 0. 809 and in wild species, from 0. 767 to 0. 809 in the same genotypes, and from 0. 570 to 0. 745 between different genotypes. A consensus tree indicated that the genus Zea can be classified into two sections. Zea and Luxuriantes. Section Zea consists of four subspecies： Z. mays ssp. mays, Z. mays ssp. mexicana, Z. mays ssp. parviglumis and Z. mays ssp. huehuetenangensis. Section Luxuriantes is composed of Z. diploperennis, Z. luxurians and Z. perennis, as well as Z. nicaraguensis. Z. nicaraguensis was genetically closer to Z. luxurians than to other teosintes. In conclusion, polymorphism information obtained using RAPDs in a set of genotypes is useful for the assessment of genetic relationships and could be useful in taxonomic classification programs.