Temporal And Spatial Genetic Structure In Abies Ziyuanensis Population In Dayuan, Hu'nan

Abies ziyuanensis, which is survived the Quaternary glaciation stage, is a member of Pinaceae family. A.ziyuanensis distributed in Yinzhulaoshan of Guangxi, Shunhuangshan and Dayuan of Hu'nan. The distribution of Dayuan is the largest and good natural regeneration population. In this study, the distribution of A. ziyuanensis populations in Dayuan of Hu'nan was investigated. Leaves of adult and seedling trees were sampled in Zhongniushi, Xianggupeng, Jimajie and Hepingao.The adult trees were precisely positioned. Using SSR, cpSSR molecular markers and chloroplast DNA sequences (rrn5-trnR, matK) analyzed all the samples, to study clearly the population structure and spatial distribution pattern of the age, reveale the resources of temporal and spatial genetic structure of A. ziyuanensis populations in Dayuan. The main conclusions were as follows:1. The results showed that old individuals were less in the population of A. ziyuanensis in Dayuan, the population age structure is relatively stable. In the four populations, Zhongniushi had serious lack of age class.2. The point pattern analysis showed that when the size was 30×30m, the Zhongniushi plot showed random distribution in the smaller scale extent and presented stochastic mode at scales>8m, While the other three plots were clustered distribution. Population fractal characteristics reflect that both the population pattern of intensity scale and the capability of occupy space were weak. Among the four populations, the capability of occupy space in Hepingao is the strongest, the individual in this population is most uneven distribution, population regeneration is the best. While the capability of occupy space in Jimajie is the weakest, the individual in the plot is relatively even distribution, the population regeneration is the worst.3. Genetic diversity in A. ziyuanensis population showed that the level of diversity was low, this mainly related to the distribution of the A. ziyuanensis population and the bottleneck was happened in the population. In the four populations, the genetic diversity decreased from Hepingao, Xianggupeng, Zhongniushi to Jimajie.4. Genetic differentiation among different size classes was analyzed in A. ziyuanensis, to reflect its temporal genetic differentiation. No significant differences were found in different size classes, the temporal structure was stable, and the gene can transfer in generations. The temporal genetic structure in the four populations were respectively studied, the result also showed that the difference among different size classes was low. The genetic diversity in different size classes decreased from 5(old tree), 3(middle tree), 4(adults), 2(juveniles) to 1(seedlings).5. The population spatial genetic structure in A. ziyuanensis is clear. There was clear genetic differentiation between the Hepingao population and the other three populations. This relate to low gene flow among populations and the distribution of A. ziyuanensis population. Spatial autocorrelation analysis was used to study the fine-scale spatial genetic structure of the natural populations of A. ziyuanensis. The result revealed significant spatial structure of genetic variation in smaller scale in population of Hepingao. While the genetic variation in populations of Xianggupeng and Jimajie was found to be lack of spatial structure, which randomly distributed.6. Based on all the analysis, the strategies to conserve A. ziyuanensis population were also discussed. Such as promote the gene flow among the populations, focal protecting Hepingao population and so on.