秦岭秀雅杜鹃野生种群遗传多样性和遗传分化的AFLP分析

Genetic diversity and genetic differentiation of Rhododendron concinnum wild populations in Qinling Mountains of Northwest China: An AFLP analysis

利用AFLP分子标记技术,对秦岭地区7个秀雅杜鹃野生种群的遗传多样性和遗传分化进行研究.结果表明:M52E41、M62E46和M64E94等3个引物组合共扩增出182条DNA片段,其中151条是多态的,多态位点比率为83.1%.7个秀雅杜鹃种群所检测的多态位点百分率(PPL)、Nei的基因多样性指数(h)和Shannon信息指数(I)的变化趋势一致,其排序为眉县种群>柞水种群>镇安种群>户县种群>宁强种群>南郑种群>周至种群.POPGENE分析表明,秀雅杜鹃在物种水平(PPL=91.22%,I=0.7217,h=0.5095)和种群水平(PPL=77.56%,I=0.6409,h=0.4725)都具有较高的遗传多样性.种群间的遗传分化系数(Gst)为7.26%,说明有92.74%的变异存在于种群内部.AMOVA分析表明,在总的遗传变异中,85.3%的变异发生在种群内,14.7%的变异发生在种群间,说明秀雅杜鹃种群的遗传变异主要存在于种群内部.UPGMA聚类分析表明,种群间的遗传距离与种群间的地理距离没有明显的相关性.最后提出了秦岭地区秀雅杜鹃种质资源的保护策略.

By using amplified fragment length polymorphism （AFLP） technique, an investigation was made on the genetic diversity and genetic differentiation of seven wild populations of Rhododen- dron concinnum in Qinling Mountains of Northwest China. A total of 182 amplification products were generated from three AFLP selective primer combinations, of which, 151 were polymorphic. The percentage of polymorphism was 83.1%. The change trends showed by the percentage of polymor- phic loci （PPL）, Nei＇s gene diversity （h） , and Shannon＇ s information index （I） were uniform, and the order of the populations was Meixian 〉 Zhashui 〉 Zhen＇ an 〉 Huxian 〉 Ningqiang 〉 Nanzheng 〉 Zhouzhi. The POPGENE analysis showed that the R. concinnum had higher genetic di- versity at both species level （ PPL = 91.22%, I = 0.7217, h = 0.5095 ） and population level （ PPL = 77.56% , I = 0. 6409, h = 0. 4725 ）. The coefficient of gene differentiation among the populations （ Gst ） was 0. 0726, indicating that 92.74% of genetic variation occurred within the populations. The analysis of molecular variance （AMOVA） showed that 85.3% of the genetic variation was within the populations, and 14.7% of it was among the populations. The unweighted pair group method with arithmeticmean （UPGMA） indicated that there was no significant correlation between the genetic distance and the geographic distance among the R. concinnum populations. The conser- vation strategies for R. concinnum germplasm resources were put forward.