食用海带(Saccharina japonica)新品系遗传多样性研究

Study on Genetic Diversity of Four New Saccharina japonica Cultivars

中文关键词: 海带  遗传多样性  SSR  聚类分析  AMOVA

英文关键词: Saccharina japonica  Genetic diversity  SSR  Cluster analysis  AMOVA

中文摘要:

      为获取3个食用海带(Saccharina japonica)新品系(“海天1号”、“海天2号”、“海天3号”)和“黄官1号”海带的遗传多样性和遗传结构信息，为海带种质保存及新品系培育提供理论依据，本研究采用SSR分子标记技术，从20对SSR引物中筛选出8对扩增效果好的引物，对4个海带品系的120个样本进行了种群遗传分析。结果显示，8对引物共检测到28个具有多态性的等位基因，9个特异性等位基因，平均每对引物检测到等位基因数为4.6250个。4个海带品系的Nei¢s基因多样性(H)和香农指数(I)平均值分别为0.3809和0.6702，遗传多样性水平偏低，且亲缘关系较近。其中，“海天1号”海带的H、I值最高，多态性位点最多，遗传多样性优于其他3个海带品系。“海天2号”、“海天3号”和“黄官1号”海带遗传多样性水平依次降低。聚类分析结果显示，“海天1号”与“海天3号”海带亲缘关系最近，而与“黄官1号”海带亲缘关系最远。AMOVA分析显示，4个海带品系92.06%的变异来源于品系内部，7.94%的变异来源于品系间。“黄官1号”海带的遗传多样性在4个海带品系中最低，以其作为亲本培育新品种时，应注意提高子代的遗传多样性。遗传多样性最高的是“海天1号”，可充分利用其优点培育优良的新品系。

英文摘要:

      In order to provide reliable theoretical basis for high-efficiency utilization of Saccharina japonica germplasm resources in its breeding practice, the information of genetic diversity and structure of three new edible S. japonica cultivars (including “Haitian No.1”, “Haitian No.2” and “Haitian No.3”) and “Huangguan No.1” were explored in this study. We selected eight pairs of primers for the simple sequence repeat (SSR) molecular marker technique to test the genetic diversity of 120 samples of the four S. japonica cultivars. From 20 pairs of SSR primers published online, eight pairs were identified because of their good amplification patterns on the majority of 120 DNA templates. The results showed that 28 polymorphic alleles and 9 specific alleles were detected by eight SSR markers, and the average alleles per primers detected were about 4.6250. The Nei¢s gene diversity (H) and the Shannon index (I) of the four S. japonica cultivars were 0.3809 and 0.6702, respectively. It indicated that the genetic diversity of the four S.japonica was relatively low and four species were genetically related. Among them, the Nei¢s gene diversity (H), Shannon¢s information index (I) and the number of polymorphic alleles were the highest in “Haitian No.1”. This indicated that the genetic diversity of S. japonica of “Haitian No.1” was higher than other three S. japonica cultivars. The levels of genetic diversity of “Haitian No.2”、“Haitian No.3” and “Huangguan No.1” decreased successively. Cluster analysis demonstrated that the relationship between “Haitian No.1” and “Haitian No.3” was close, but the relationship between “Haitian No.1” and “Huangguan No.1” was not. AMOVA analysis showed that about 92.06% of the variation was derived from individuals of the four S. japonica cultivars, and 7.94% of the variation was derived among the four S. japonica cultivars. The genetic diversity of “Huangguan No.1” was the lowest, suggesting the need of strengthening the biodiversity protection; the highest genetic diversity was the “Haitian No.1”, and could be used for developing new cultivars.