鄂报春Primula obconica作为一种广泛栽培的园艺植物,其野生居群的遗传多样性及遗传结构的研究还少见报道。本文通过叶绿体微卫星分析了17个鄂报春野生居群(共278个个体),共发现4个多态性位点(16个等位基因),得到14个单倍型。结果表明鄂报春具有很高的总基因多样性(HT=0.971)和极低的居群内基因多样性(HS=0.028);分子方差分析(AMOVA)显示98%的变异存在于居群间。这些结果说明早期的生境片断化及有限的种子传播能力是造成当前遗传结构的重要原因。Nst值显著大于Gst值,表明关系相近的单倍型会出现在相同的地区内,同时最小生成树(MST)的分析结果证实了这样的结论。我们在最小生成树的两个组中推断出一些古老单倍型,并推测在冰期时湖北和我国的西南地区可能是该物种的避难所。
Primula obconica has been cultivated widely as a popular garden plant. In order to discover the pattern of genetic diversity and the evolutionary process, a total of 278 individuals from 17 populations throughout its distribution in China were analyzed using chloroplast microsatellites (cpSSRs) markers. Four loci and a total of 14 haplotypes were identified by our data set. The total gene diversity (HT =0.971) is high, while gene diversity within populations (HS=0.028) is low. Analysis of molecular variance (AMOVA) shows that about 98% variation is among populations. The results suggest that past fragmentation and limited dispersal ability of seeds might play important roles in forming the present genetic structure. A significantly higher value of Nst than that of Gst indicates that closely related haplotypes are often found in the same area, and we found two different groups in the minimum spanning tree (MST), which occupy different geographic regions. Furthermore, older haplotypes were detected in the two groups, respectively. Possible refugia are inferred in western Hubei Province and SW China during the glacial period.