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以中国新疆灰叶胡杨(Populus pruinosa)的9个天然居群的135个样品为材料,利用12对荧光SSR引物对其遗传多样性和遗传结构进行研究。结果表明:12对引物共检测到136个位点,平均每个引物11个条带,居群的平均多态位点比率平均为0.972、Shannon指数(I)平均为1.185、Nei指数(h)平均为0.541、观察杂合度Ho为0.321、期望杂合度He为0.560,表明灰叶胡杨的遗传多样性水平较丰富。9个灰叶胡杨天然居群中泽普居群的遗传多样性最为丰富,阿拉尔14团遗传多样性最为贫乏。AMOVA分子差异分析显示:12%的遗传变异存在居群间,88%的遗传变异则存在居群内,基因分化系数Gst为17.10%,证明灰叶胡杨居群的遗传分化程度较低。根据遗传分化系数,测得居群间的基因流(Nm)为2.424。9个居群的平均遗传距离为0.244,14T居群和MGT居群遗传距离最近,遗传一致度最大。利用UPGMA法对9个居群进行聚类分析,灰叶胡杨9个自然居群分为4大类:48团(48T)、14团(14T)、麦盖提县(MGT)、墨玉县(MY)、沙雅县(SY)聚为一大类,阿瓦提县(AWT)和阿拉尔和田河古道(ALE)居群聚为一大类,最后泽普县(ZP)、巴楚县的夏马勒林场(XML)各自单独为一类。经Mantel检验,9个灰叶胡杨居群的遗传距离和地理距离相关性不显著。总之,泽普居群遗传多样性最丰富,因此在指定原位种质保护计划时应优先考虑泽普居群。
The genetic diversity and genetic structure of 135 samples from nine natural populations of Populus pruinosa in China were studied using 12 pairs of fluorescent SSR primers. The results showed that a total of 136 loci were detected by 12 pairs of primers with an average of 11 bands per primer. The mean polymorphic loci ratio of population was 0.972, Shannon index (I) was 1.185, Nei index (h) The average was 0.541, the observed heterozygosity Ho was 0.321, and the expected heterozygosity He was 0.560, which indicated that the genetic diversity of Populus euphratica was rich. Nine Populus euphratica natural populations in the Zepu population is the most abundant genetic diversity, Alar14 group of the most poor genetic diversity. Analysis of AMOVA molecular differences showed that 12% of genetic variation existed among populations and 88% of genetic variation existed within populations. The genetic differentiation coefficient Gst was 17.10%, which proved that the genetic differentiation of Populus tomentosa population was low. According to the genetic differentiation coefficient, the genetic distance (Nm) between populations was 2.424.9, and the average genetic distance was 0.244. The genetic distance between the 14T population and MGT population was the closest, and the genetic identity was the highest. The cluster analysis of 9 populations by UPGMA method was conducted. Nine natural populations of Populus euphratica were divided into four groups: 48 (48T), 14T (14T), MGT, (MY), Shaya (SY) clustered into one large group, Awat (AWT) and Alar and the Arita River clustered into one large group, and finally Zepu County (ZP), Bachu The county’s mare forest site (xml) is a separate category. The Mantel test showed that there was no significant correlation between the genetic distance and geographical distance of Populus euphratica population. In summary, the Zepperian population has the most genetic diversity and therefore, the Zopu population should be prioritized when designing in situ germplasm conservation programs.