鼎湖血桐种群生物学及遗传多样性初步研究

Population biology and genetic diversity of Macaranga sampsonii

采用点格局分析、径级结构分析以及微卫星筛选等方法,对鼎湖山保护区20hm2永久样地中的鼎湖血桐进行了种群生物学及遗传多样性研究。结果表明:鼎湖血桐是一种r-对策型阳生植物,种群年龄结构呈金字塔型;植株受光照不足的胁迫,种群大部分个体聚集分布于光照充足的林窗中;通过磁珠富集法筛选出鼎湖血桐特异性微卫星引物13对,其中2对具备多态性,多态百分率为15.4%,多态信息含量在0～0.3734之间,平均期望杂合度为0.0756,远低于同属其它植物。研究表明鼎湖血桐对环境变化的适应范围较窄,遗传多样性较低,应对其种质资源进行多样性评估与保护。

An analysis of population biology and genetic diversity of Macaranga sampsonii was taken in DHS-20-hm2 permanent plots,which locates on the Dinghushan natural reserve. By use of point pattern analysis and DBH-class structure analysis,it was concluded that M.sampsonii was a light-dependent egy,whose population age structure was approximately pyramid-like. The population habitat was restricted in the canopy gaps because of sunlight deficiency stress. Thirteen microsatellite loci were isolated by methods of magnetic beads enrichment,in which only two loci（15.4%）were polymorphic. The polymorphic information content of these loci ranged from 0 to 0.3734.The average expected heterozygosity of M.sampsonii was 0.0756,which was obviously lower than other Macaranga species. These results indicated that M.sampsonii was in a narrow environment adaptation range and a low population genetic diversity. We should take measures to evaluate and protect its germplasm resource.