【作者】 胡世俊；

【导师】 何平；

【作者基本信息】 西南师范大学 ， 植物学， 2004， 硕士

【摘要】 本文以处于濒危状态的缙云卫矛为研究对象，在测定了各种群的生存环境因子基础上，从形态和等位酶两个层次采用多种数量分析方法对缙云卫矛7个种群97个个体的29项形态指标及6种等位酶反映出的生态遗传分化及其与环境的关系进行了研究。结果表明： ● 形态分化的方差分析表明，在所研究的29项形态指标中有8个性状的变异达显著水平，6个达极显著水平，说明个体之间在形态上有一定程度的分化。 ● 在所研究的形态性状中，其差异程度表现出：营养器官的变异大于生殖器官的变异，所测量的生殖器官性状的变异均没达到显著水平，这说明形态分化主要表现在营养器官特征上，也说明营养器官受环境影响较大。 ● 对所测量的形态特征的数据在个体水平上进行聚类结果表明，同一种群的个体并不是完全有序地聚在一起，而不同种群间的个体常无序地聚在一起，同时也有一些大的表征群不出现某些种群的个体，说明部分种群间有一定的分化，这也反映了种群内部个体间的遗传异质性或由于种群内部微生境的差异导致的种群内个体间的形态异质性。 ● 对形态数据在种群水平上进行聚类结果表明，东温泉的两个种群与其它种群之间存在明显的形态分化，这种分化可能与它们之间的地理隔离有关。 ● 形态分化与环境因子的灰色关联度分析表明，29个形态性状中，有26个性状的第一影响因子是全钾的含量。从总体上看，对形态性状影响最大的几个环境因子是全钾、土壤pH值、海拔、吸湿水的含量。可见，影响缙云卫矛生长的主要的主导因子来自于土壤条件。 ● 检测了6个酶系统，它们是：过氧化物酶、细胞色素氧化酶、超氧化物歧化酶、酯酶、淀粉酶、苹果酸脱氢酶。共检出酶谱带42条，等位基因位点15个，其中多态位点12个，单态位点3个，多态位点百分数P=80％，平均每个位点的等位基因数溯危植物姗云卫矛‘及心砂侧侈动2~tho，’山5 Yang)生态遗传分化研究A=1 .8个，平均每个位点的等位基因有效数为Ae=1.13。平均预期杂合度He二0.416，实际杂合度H0=0.774.表现出较高的遗传多样性水平..种群间的基因分化水平不高，其Gst二0.206，表明其遗传多样性大都来自于种群内部，而仅有20.战的遗传多样性来自于种群之间，种群间的遗传距离都很小，Nm=0 .964;表明种群间有一定强度的基因流..位点杂合度与环境因子的灰色关联度表明，各位点杂合度的主要影响因子有所变化，但总体上来说影响较大的主要的几个环境因子是全钾、pH值、海拔，这与前面形态特征与环境因子灰色关联度分析所得结论基本一致。.通过酶谱带分析及从各位点的杂合度来看，该物种的遗传多样性仍较高，但其种群已呈岛屿状分布，这将不利于种群间的墓因交流，将会导致杂合度的降低、遗传多样性下降。.通过对等位酶二态数据的聚类分析表明，不同种群的个体常混聚在一起，表明种群内部个体遗传异质性较高，与通过基因分化系数得出的遗传多样性主要存在于种群内部这一结论一致。对基因频率及遗传一致度的聚类分析表明种群5与其它种群的分化相对较大。.形态分化的研究结果表明种群6、7与其它种群分化较大，但等位酶分析表明种群间的遗传分化并不大，这说明绪云卫矛在形态上受环境影响较大。更多还原

【Abstract】 In this paper, with the helps of the ordinary ecological site-study techniques, electrophoresis and the multivariate analyses, from both the levels of morphological and allozymic variation, we studied the differentiation patterns of 29 morphological characters and 6 allozymes of 97 individuals from 7 populations of Euonymus chloranthoides Yang, an endangered plant species which is endemic to Mt. Jinyun of Chongqing. We also studied the relationship between such differentiation and its environment factors. The result shows that:The result of ANOVA of morphological differentiation shows the that 8 of the 29 studied characters indicate notable differentiation among individuals and 6 characters even reach the extremely notable level, which means that there does exist morphological differentiation among the individuals to a certain extent.The differentiation of the studied morphological characters shows that the differentiation of vegetative organs is greater than that of reproductive organs and the differentiation of reproductive organs doesn’t reach the notable level, which indicates that the morphological differentiation mainly occurred in the vegetative organs and is caused mainly by environment factors.The result of the cluster analysis at the individuals level shows that most of the individuals from different populations cluster together and the individuals from one or two populations doesn’t emerge in some phenons, which means that certain degree of morphological and genetic differentiation occurred among populations. This also reflects that there is genetic heterogeneity among individuals or the variation of micro-habitats in a same population.From cluster analysis at the population level we found that there is obvious differentiation between the populations from East hot spring and the populations from other places, this differentiation probably caused by the geographical isolation among those populations.The value grey relatedness degree matrix between morphological characters and environment factors shows that the content of K in the soil is the most important factor to cause the morphological variation of 26 characters of totally 29 studied. Generally speaking, the content of K in soil, pH of the soil, altitude and the content of hygroscopic water are the most critical factors to cause the morphological differentiation of E. chloranthoides Yang. The dominant factors affecting the growth of the endangered plant E. chloranthoides Yang come from the soil.We have tested 6 allozymic systems, they are PER,CYT,SOD,ES,AMY and MDH. There are totally 42 allozymic bands with 15 loci of which 12 are polymorphic and 3 are monomorphic. The percentage of polymorphic loci (P) is 80%. The mean number ofalleles per locus (A) is 1.8, and the effective number per locus (Ae) is 1.13. The mean observed heterozygosity per locus (Ho) is 0.774, which indicates the high level of overall genetic diversity in this species. But we should note that the genetic divergent level is not high with Gst of 0.206, which indicates that the genetic diversity mainly exists within the population while only 20.6% genetic variation is among the populations. The genetic distance among populations is very small with Nm of only 0.964, which indicates that there is obvious gene flows among the populations to some extent.The result of the analysis on the gray relatedness degree between percentage of loci heterozygosity and environment factors shows that the main factors affecting percentage of loci heterozygosity are the content of K in soil, pH of soil and the altitude. It is in accordance with the result from the analysis on the gray relatedness degree between morphological differentiation and environment factors.According to the percentage of per locus heterozygous and the analysis of allozymic bands, we can deduce that the genetic diversity of this species is still rich. But presently, E. chloranthoides Yang is only with isolated small populations, which will prohibit the gene flow among populations and decline the gene更多还原