中文摘要：

拟南芥（Arabidopsis thaliana）是植物生物学的模式植物,在分子遗传学方面已经积累了丰富的研究成果,但目前对拟南芥自然分布的生境特点、表型变化的环境依赖特征等研究很少,极大地限制了对拟南芥进化动力和机制的理解。为了了解在微环境下拟南芥种群分布和表型性状的变化特点,对天山北部分布于塔尔巴哈台山、阿尔泰山和天山的10个拟南芥种群的分布特征、表型的变化特点,以及与综合环境因子的相互关系进行了分析。结果表明：除分枝数外,株高、株重、根重、单个果实重量、单株果数、单株果重、果长、果实开裂力度、单株果重/总重9个特征在种群间变化显著,可塑性能力较强;但方差分析和变异系数结果显示,角果长度、果实开裂力度在种群内和种群间的变化相对较小。表型特征在山系间、经纬度和海拔间的变化规律不明显。拟南芥主要分布于pH值和HCO3–含量低,有机质丰富,且有一定坡度的沙土地块上。种群内拟南芥分布频度很低,在1.56%–10.69%之间,空间自相关距离在15.4–46.7cm之间变化较大,10个种群均呈现极显著集群分布,分布的集群性受果实开裂力度的影响显著,而果实开裂力度随环境胁迫而极显著增加。总结认为：天山北部拟南芥生长和分布主要受微环境的影响,在干旱环境下,拟南芥主要通过增加繁殖分配比例,产生难开裂的果实,促使种子短距离扩散于母株周围,确保子代利用原适宜生境来生存繁衍。

英文摘要：

Aims Little research has been done on natural environmental factors that impact phenotypic characters of Arabidopsis thaliana populations in their natural habitat.Our objective was to determine the distribution patterns of phenotypic characters and the relationship of phenotypic characters and environmental factors of A.thaliana populations.Methods From May to June 2009,we studied ten populations in the northern Tianshan Mountains.We placed 10 m × 10 m quadrats at each population plot,each comprised of about 400 smaller（0.5 m × 0.5 m） quadrats,and investigated the distributional patterns of populations and nine environmental factors.Twenty A.thaliana plants were selected,and ten phenotypic characteristics（branch number,plant height,plant biomass,root biomass,single fruit weight,fruit number per plant,fruits weight per plant,fruit length,fruit dehiscence force,fruit weight per plant/total weight） were measured.Variance,principal component and regression analyses were used.Important findings All phenotypic characteristics except branch number showed significant differences among populations,which indicated that there is strongly plasticity in the nine characters.The results of the analysis of variance and coefficients of variance indicated that fruit length and fruit dehiscence force have little variation within and among populations.Phenotypic characters varied little among different mountains,altitudes,latitudes and longitudes.The results indicated that A.thaliana populations mainly distributed on sandy soils that contained lower HCO3–,pH values and higher soil organic carbon（SOC）.The distribution frequencies of A.thaliana within populations are very low,ranging from 1.56% to 10.69%,with spatial autocorrelation distances being 15.4 to 46.7 cm and variable.Ten populations were all highly clumped in their distribution（p 0.01）,which was significantly correlated with the fruit dehiscence force,while the fruit dehiscence force increased as environmental stress increased.Results suggested that the g