【作者】 刘招辉；

【导师】 唐绍清；

【作者基本信息】 广西师范大学 ， 植物学， 2010， 硕士

【摘要】 资源冷杉(Abies ziyuanensis)是松冷杉属濒危物种。分布于广西资源县和湖南城步县交界的银竹老山、湖南新宁县和东安县交界的舜黄山及湖南炎陵县大院,湖南炎陵县大院分布点是种群数量最大、自然更新良好的分布点。本研究对分布于湖南炎陵县大院的资源冷杉种群进行样地调查,在中牛石、香菇蓬、鸡麻捷和和平坳4个自然分布亚种群内采集成年植株及幼苗叶片,并对每个成体单株进行精确定位,采用SSR、cpSSR分子标记及叶绿体DNA序列(rrn5-trnR、matK)对样品进行了分析,目的在于,研究清楚资源冷杉大院种群的年龄结构和空间分布格局。揭示资源冷杉大院种群的时间和空间遗传结构。研究结果表明:1.资源冷杉大院种群老龄个体较少,中龄级个体占多数,种群趋于相对稳定。在调查的4个地段中,中牛石亚种群存在严重的龄级缺失。2.当样方大小统一为30×30m时,中牛石居群在较小的尺度上聚集分布,在尺度大于8m以后,种群成随机分布。其余三个地段,种群在1-15m的尺度上均呈聚集分布。种群分形特征研究表明,资源冷杉大院种群格局强度的尺度变化、占据空间能力都很弱。在研究的4个地段中,和平坳地段的资源冷杉种群空间利用能力最强,个体分布最不均匀,种群更新状况最佳。鸡麻捷地段资源冷杉种群占据空间能力最弱,个体分布较均匀,种群更新能力最差。3.对资源冷杉大院种群的遗传多样性研究表明,资源冷杉大院种群的遗传多样性较低,这主要与资源冷杉大院种群的分布,种群发生过瓶颈效应有关。在四个亚种群水平中,遗传多样性水平从高到低依次为:和平坳>香菇棚>中牛石>鸡麻捷。4.对资源冷杉大院种群的总体时间遗传结构表明,不同年龄等级各亚种群间遗传差异不大,时间遗传结构比较稳定,基因能够世代延续。分别对4个亚种群的时间遗传结构研究亦表明,遗传变异主要存在于龄级内,龄级间变异较小。不同年龄等级的遗传多样性由高到低为:5龄级>3龄级>4龄级>2龄级>1龄级。5.资源冷杉大院种群整体空间遗传结构比较明显,和平坳亚种群与其它三个亚种群存在着明显的遗传分化与差异,这主要是资源冷杉各亚种群间基因交流较少及资源冷杉大院种群的分布地区有很大关系。利用空间自相关分析资源冷杉大院种群天然亚种群小尺度范围的空间遗传结构,结果揭示资源冷杉和平坳亚种群在小尺度范围内呈现出空间遗传结构斑块状,而香菇棚和鸡麻捷亚种群的遗传变异缺乏空间结构,表现为自然状态下的随机分布。6.根据以上研究结果,对资源冷杉大院种群的保护提出了相应的策略:人为促进各亚种群间的基因交流、重点保护和平坳亚种群等。更多还原

【Abstract】 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.更多还原