4种紫菜叶状体的ISSR分子标记分析

Inter-simple sequence repeats(ISSR) applied in four species of Porphyra(Rhodophyta,Bangiales)

4种紫菜样品分别为采自青岛海区的野生条斑紫菜（Porphyra yezoensis）、华北半叶紫菜（P.katadai var.hemiphylla）、少精紫菜（P.oligospermatangia）和浙江象山海区人工栽培的坛紫菜（P.haitanensis）.取其10～15 cm叶状体为材料,采用ISSR（Inter-simple sequence repeats）分子标记进行分析.从100个ISSR引物中筛选出22个引物,扩增出清晰、可重复的条带共计247条,其中多态性条带比例达95.5%.根据扩增结果进行的聚类分析显示,条斑紫菜和少精紫菜的亲缘关系最为接近,在聚类图中二者首先聚在一起,接着与坛紫菜相聚,最后与华北半叶紫菜汇聚.本研究还讨论了紫菜属海藻的遗传多样性以及种间的特异性ISSR分子标记.本研究目的在于为紫菜遗传变异、亲缘关系以及分类研究、探索新的分析手段.[中国水产科学,2006,13（3）：371-377]

The red algal genus Porphyra, with more than 134 described species, is a common and conspicuous component of rocky intertidal habitats in temperate marine waters worldwide. Members of the genus Porphyra have a life cycle that between two dissimilar phase： the foliose gametophyte usually reffered to as the ＂conchocclis＂, and the filamentous sporophyte. Up to now little has been known about the systematics of Porphyra due to taxonomic difficulties inherent in a large but morphologically simple genus. In this study, four familiar species of leafy thalli of Porphyra in the sea areas in China, P. yezoensis, P. katadai var. hemiphylla, and P. oligospermatangia were collected from the beach of Qingdao, except P. haitanensis which was cultivated in the coast of Xiangshan in Zhejiang. Among 100 ISSR primers, 22 could produce 247 clear and repeatable bands, of which 236 bands appeared to be polymorphic （95.5%）. Genetic distance was calculated and the culster analysis was performed based on the ISSR amplified results. The nearest genetic distance was 0. 524 between P. yezoensis and P. oligospermatangia from the beach of Qingdao and the farthest was 0. 719 between P. katadai var. hemiphylla and P. oligospermatangia from different sea areas. The phylogenetic tree, according to the genetic distance matrices with the method of UPGMA, showed the relationship among the four species of Porphyra. An ISSR branch was formed between P. yezoensis and P. oligospermatangia , then P. haitanensis was clustered, and P. katadai var. hemiphylla got together with them finally. The phylogenetic relationship was consistent with that by traditional method. Of these polymorphic bands, four peculiar bands, which appeared in the four species of Porphyra respectively, could be the unique bands of them by further study. The results indicate the difference of the important biological characters among the four species of Porphyra, such as the number of chromosome and the types of reproduction, was correlated with the cluster results. The results also reflects that ISSR technique is valid on the relationship in Porphyra.