阿拉善荒漠区沙冬青种群特征与遗传多样性

摘要

Ammopiptanthus mongolicus istheimportant constructive species inAlxa desert region,which has important significance to maintain the stability of the ecological system. By natural conditions and human activities, to some extent,the distribution of this species gradually reduced, and is now in severe endangerment.Study on different habitats of Ammopiptanthus mongolicus inAlxa by using technique of RAPD molecular markers and adopting field investigation with analysis of data statistics, in this paper we give the following results:
　　1.The Ammopiptanthus mongolicuswhich distribute in mountains, fixed sandy land and half -fixed sandy land are in decline stage, the situation is in contrast with the other region, such as alluvial fan. The Habitat in alluvial fan is more suitable for the growth and breeding , so it should be especially protected.
　　2.The spatial pattern of the whole population is contagious distribution in all kinds of Habitat, but it shows a different aggregation degree, in which the biggest aggregation degree is the plant in alluvial fan. Along with the growth ofAmmopiptanthus mongolicus, the phenomenon ofself-thinning become more and more significant,. On the country, the aggregation degree gradually decreased.
　　3. The genetic distances being 0.3078-0.6870 and the identity being 0.5031-0.7351 among populations. The genetic relationships among Luanjingtan (LJT) and Yabulai (YBL) are relatively close, the genetic relationships among Jiangui (JG) and Helanshan (HLS) are relatively close. Theformations of phenotypic characteristics was mainly influenced by the habitat, were no obvious connection with genetic relationships.
　　4.Through cluster analysis on the RAPD bands, The percentage of polymorphic bands (PPB) was 55.36％, the genetic diversity from high to low was found respectively in Helanshan（HLS）>Luanjingtan（LJT）>Jiangui（JG）>Yabulai（YBL）>Jilantai（JLT）. Effective number of alleles, Nei’s gene diversity and and Shannon’s information index were 1.6073, 0.3468 and 0.5119 at species level. The results indicate thatAmmopiptanthus mongolicus in this area has relatively low genetic diversity and most of differentiation is within populations.
　　5.The overall region start with western part of Yinshan Mountain then along Helan Mountains once was continuous distribution, obstructed by the Ulan Bub Sandy Land,nbsp;Kubuqi Desert, Tungeli desert and Badan Jilin desert, formed Jilantai population.

目录

声明

1 引言

1.1 研究背景

1.2 国内外研究现状

1.2.1 植物种群生态学研究

1.2.2 种群结构和空间分布格局研究

1.2.3 遗传多样性研究

1.3 研究目的与意义

2 研究区概况

2.1 地理位置

2.2 气候条件

2.3 地形地貌

2.4 植被条件

3 研究方法

3.1 样地设置与调查

3.2.1 种群结构分析方法

3.2.2 种群空间分布格局分析方法

3.3 遗传多样性研究

3.3.1 DNA提取与检测

3.3.2 DNA质量检测

3.3.3 RAPD-PCR反应体系的建立

3.3.4 引物筛选

3.3.5 反应产物检测

3.3.6 数据处理与分析

4.1 种群特征

4.1.1 不同生境沙冬青种群株高结构特征

4.1.2 不同生境中沙冬青种群冠幅结构特征

4.1.3 不同生境中沙冬青种群生长状况

4.1.4 不同生境沙冬青种群年龄结构

4.1.5 沙冬青种群空间分布格局

4.2 遗传多样性

4.2.1 DNA检测结果

4.2.2 RAPD引物筛选与扩增结果

4.2.3 遗传多样性分析

4.2.4 遗传距离和聚类分析

4.3种群特征与遗传多样性综合分析

5 讨论与结论

5.1 讨论

5.2 结论

致谢

参考文献

作 者 简 介