利用SSR标记技术对来自海南、广东、广西的19个美丽鸡血藤野生居群的遗传多样性进行了研究。10个位点共检测到66个等位基因,每个位点3~12个,平均6.6个。来自海南和广东的种质中分别检测到14和2个特有等位基因。物种水平上,多态位点百分比(P)、Nei’s基因多样性指数(H)和Shannon’S信息指数(I)分别为84.62%、0.1717和0.2836.以居群XL(P44.87%、H0.1563、I 0.2356)和QZ(P46.15%、H0.1473、,0.2264)最高,居群HL(P6.41%、H0.0266、I 0.0388)最低,海南种质较内陆种质拥有更高的遗传变异。居群间基因分化系数(Gst)为0.5139,基因流(Arm)为0.4729,表明居群问存在较高的遗传分化。聚类分析表明所有样本可聚为4类,但地域性特征并不明显。由上述结果推测,生活史特征、繁育系统和历史事件可能对美丽鸡血藤遗传变异格局的形成产生了一定的影响。
Simple Sequence Repeat (SSR) technique was used to determine the genetic diversity of nineteen geographically isolated wild populations of Callerya speciosa(Champ, ex Benth.) Schot from Hainan, Guangdong and Guangxi. A total of 66 alleles were detected at the 10 loci. The number of alleles per marker ranged from 3 to 12 with an average of 6.6 per locus. Fourteen private alleles were detected in Hainan populations, while only two private alleles detected in Guangdong population. At the population level, the percentage of polymorphic loci (P), gene diversity (H) and Shannon's information index (I) was highest in XL(P 44.87%, H 0.1563, 1 0.2356) and QZ population(P 46.15%, H 0.1473, 1 0.2264) and lowest in HL population(P 6.41%, H 0.0266, 1 0.0388). At the species level, P, H, and I were 84.62%, 0.1717 and 0.2836, respectively. A relatively higher level of variation was revealed in accessions from Hainan Island than those from mainland population. The Gst value was 0.5139 and the gene flow (Nrn) was 0.4729, indicating strong genetic differentiation among populations. Additionally, a UMPGA dendrogram was constructed based on the Dice similarity coefficients among individuals, which generally revealed four major elades but not according to their geographic origins. Life form, breeding system and historical effects were suggested to play main roles in the shaping of genetic variation pattern.