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红豆树(Ormosia hosiei Hemsl.et Wils)是中国特有的珍稀濒危植物,但其遗传信息了解较少。为进一步完善红豆树遗传背景研究,采用SSR分子标记技术对江西省资溪县泸溪河、福建省柘荣县茜洋溪和浙江省龙泉市瓯江上游等3个小流域的9个红豆树天然居群的遗传多样性及遗传分化进行分析。本研究利用12对SSR引物在193个个体中共检测到171个等位基因,每个位点平均14.3个。不同小流域间和同一小流域内(西溪支流)不同居群的遗传多样性皆维持较高水平(HE>0.720),但也均存在一定程度的近交(Fis>0);不同流域的遗传多样性由高到低顺序:OJ(HE=0.835)、XYX(HE=0.829)、LXH(HE=0.796);西溪支流内不同居群间遗传多样性也存在一定的差异,如处在柘荣茜洋溪-西溪中游的富溪居群其遗传多样性水平最高(HE=0.771),而其上游的东源和下游的宅中居群的遗传多样性则相对较低。不同水平(流域和居群水平)的AMOVA分析表明,遗传变异主要存在于流域内和居群内,流域间或流域内居群间的遗传分化皆属于中等程度。基于遗传距离的聚类分析和Structure分组分析均表明,3个小流域的9个天然居群可归为2大群组,其中江西泸溪河小流域(LXH)和福建茜洋溪小流域(XYX)的6个居群(JXMTS,JXBHQ,FJDY,FJFX,FJCP和FJZZ)归为一群组,而浙江瓯江小流域的3个居群(ZJFX-1,ZJFX-2和ZJBD)则单独归为另一群组,且第一群组内居群间还存在较明显的遗传分化。因此,研究认为,研究的3个小流域红豆树天然居群维持较高的遗传多样性,这可能是其生境片段化前的反映。第一群组内(LXH和XYX)的遗传分化可能与居群大小、分布及生境有关,而第二群组内(瓯江上游流域)的居群则起源于一个较大的居群。
Ormosia hosiei Hemsl.et Wils is a peculiar rare and endangered plant in China, but its genetic information is poorly understood. In order to further improve the genetic background of Taxus tree, SSR molecular markers were used to analyze the genetic diversity of nine natural red bean trees in three small watersheds, including Luxi River in Zixi County of Jiangxi Province, Qianyang River in Zherong County of Fujian Province and Upper Oujiang River in Longquan City of Zhejiang Province. Population genetic diversity and genetic differentiation were analyzed. In this study, a total of 171 alleles were detected in 193 individuals using 12 pairs of SSR primers, with an average of 14.3 loci per locus. The genetic diversity of different populations in different small watersheds and in the same small watershed (Xixi tributary) maintained a relatively high level (HE> 0.720), but there was also a certain degree of inbreeding (Fis> 0). The genetic diversity in different watersheds The order of diversity varied from high to low: OJ (HE = 0.835), XYX (HE = 0.829), LXH (HE = 0.796); There were also differences in genetic diversity among different populations in Xixi Tributaries, The genetic diversity of Fuyang population in Qianyangxi-Xixi middle reaches was the highest (HE = 0.771), but the genetic diversity of the upstream and downstream populations was relatively low in the upstream. AMOVA analysis at different levels (catchment and population level) showed that genetic variation mainly existed in the basin and within the population, and the genetic differentiation among the populations in the basin or in the basin was moderate. Cluster analysis based on genetic distance and structure analysis showed that 9 natural populations in three small watersheds could be classified into two groups. Among them, the Luxi River Small Watershed (LXH) in Jiangxi Province and the Xianyanxi Small Watershed in Fujian 6 populations (JXMTS, JXBHQ, FJDY, FJFX, FJCP and FJZZ) of XYX were grouped into three groups (ZJFX-1, ZJFX-2 and ZJBD) Belong to another group, and the first group within the population there is still more obvious genetic differentiation. Therefore, the study suggests that the natural population of Glyptostroboides in the three small watersheds studied maintains a high genetic diversity, which may be a reflection of their habitat fragmentation. The genetic differentiation within the first group (LXH and XYX) may be related to the size, distribution and habitat of the population, while the population within the second group (upstream of the Oujiang River) originated from a larger population.