中文摘要：

采用简单序列重复区间（ISSR）分子标记技术对福建省的3个野生坛紫菜（Porphyra haitanensis）种群共60个个体进行了遗传多样性分析。15条引物共扩增出222个位点，其中186个位点具有多态性，多态位点百分率为83．789／6，在种群水平上，多态位点百分率为80．18％～81．53％，平均为80．93％。期望杂合度、Shannon信息指数在物种水平上分别为0．3304和0．4834；在种群水平上分别为0．3089和0．4551，表明坛紫菜种群内存在着较高的遗传多样性水平，且在三个种群间没有明显差异。依据Gst值，坛紫菜的遗传变异主要发生在种群内的个体间（占93．5％），只有6．5％的遗传变异发生在种群间，由此说明坛紫菜种群间的遗传分化水平很低，这与坛紫菜种群间充分的基因交流（Nm=7．1930）是相关的。基于遗传距离的UPGMA聚类结果表明坛紫菜60个个体并不按照其地理分布进行分群，而是随机分群的。文章最后还对坛紫菜种质资源保护的必要性进行了讨论。

英文摘要：

Porphyra haitanensis is a unique seaweed species that grows in South China and has the highest production （by weight） in Chinese aquaculture. However it has been a great loss in nori farming due to the degeneration of the germplasm quality in the last years. In order to understand the genetic background of P. haitanensis and guide its genetic breeding and germplasm resource protection, Inter-simple sequence repeats （ISSR） markers were used to investigate the genetic variations within and among 3 populations （PT, NR and DS） of P. haitanensis. The thalli samples were collected from 60 individuals. 15 ISSR primers gave rise to 222 discernible DNA bands of which 186 （83.78%） were polymorphic, indicated a considerable genetic variation at specific level. At the population level, the percentage of polymorphic bands （P） was from 80. 18% to 81.53%, 80. 93% on average. Expected heterozygosity （h） and Shannon＇s information index （I） were 0. 3304 and 0. 4834 respectively at specific level, 0. 3809 and 0. 4551 at population level. According to the value of Get, a large proportion of genetic variance （93.5%） of P. haitanensis was among individuals within population, only 6. 5% genetic variance was among populations, the results indicated that the genetic differentiation level among the 3 populations of P. haitanensis was low. And according to the value of Nm, the reason of the low genetic differentiation level among populations of P. haitanensis was the sufficient gene flow. UPGMA cluster analysis based on Nei＇s genetic distance showed that the individuals from the same population were no grouped together, but randomly. At Last, the necessary of protecting the germplasm resource of P. haitanensis also was discussed.