Chinese cherry (Cerasus pseudocerasus Lindl.) is one of the most economically domestic fruit trees in China. The rich variation of wild Chinese cherry is the most important breeding resource for existing cultivars. In order to reveal the levels and distribution of genetic variation within wild Chinese cherry of Sichuan Province, China, where is rich in wild Chinese cherry, the sequence variation of chloroplast DNA trnQ-rps16 intergenic spacer was analyzed in 145 individuals of all nine existing populations (seven from Sichuan, two from Shanxi and Guizhou provinces) of China. The results showed that trnQ-rps16 sequence were aligned with 13 polymorphic sites (1.87%), including 3 substitutions and 10 indels in 145 individuals, which revealed a low level of genetic diversity (h= 0.562,Π= 0.00184). Compared to other regions (h= 0.733, Π= 0.00243), a rather lower genetic diversity (h= 0.544,π= 0.00203) was found in the populations from Sichuan, and a large scale of genetic diversity among the seven populations was detected (h= 0-0.708; π= 0-0.00298), ranging from EM (h=0.000, Π=0.000) to TL (h=0.708, Π=0.00298). The low genetic diversity of populations may be strongly affected by founder effect and bottleneck effect because of the marginal nature, recent reduction, and consequent genetic drift of these populations. In addition, a fairly low genetic differentiation (FST= 0.21573) was found among the studied populations. This suggest that gene flow seems to originate from pronounced seed dispersal abilities of the species and it may play a significant role in shaping such a genetic structure. The long generation cycle of the species may also contribute to this structure. Based on these findings, a conservational plan for sampling or preserving fewer populations but more individuals from each population for the species was proposes.%中国樱桃(Cerasus pseudocerasus Lindl.)是我国古老的具有较高经济价值的栽培果树之一,个别性状突 出的野生中国樱桃是对现有栽培品种进行遗传改良的重要资源.四川野生中国樱桃资源丰富,为了明确该地区 野生中国樱桃群体的遗传多样性和遗传结构,文章对 9 个野生中国樱桃群体(其中 7 个分布四川,2 个来自陕西 和贵州)共 145 个个体的叶绿体基因间隔区 trnQ-rps16 序列进行了测定和分析.结果表明:9 个群体 145 个个体 的 trnQ-rps16 序列比对后共检测到 13 个多态位点,占位点总数的 1.87%,其中 3 处碱基替换,10 处插入/缺失.9 个群体总的遗传多样性水平较低(h=0.562,π=0.00184),相对于其他地区的 2 个群体(h= 0.733; π= 0.00243),四 川的 7 个群体表现出更低的遗传多样性水平(h= 0.544; π= 0.00203),且群体间的遗传多样性水平存在较大差异 (h=0-0.708; π=0-0.00298),其中北川桃龙群体最高(h=0.708,π=0.00298),而峨眉群体最低(h=0.000,π=0.000).群 体内低的遗传多样性可能与群体的边缘性所产生的奠基者效应以及近期群体收缩和随机遗传漂变造成的瓶颈 效应导致群体内遗传多样性丢失有关.此外,9 个群体遗传分化水平较低,平均 FST 为 0.21573.分析认为主要 是由于野生中国樱桃较强的种子传播能力增加了群体间的基因流动而导致遗传分化不明显,也可能与野生中 国樱桃较长的世代周期有关.针对上述研究结果,建议在资源保护中采取减少群体数目而加大群体内的个体数 量的保护策略.
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