【作者】 庄振宏；

【导师】 陈由强；

【作者基本信息】 福建师范大学 ， 植物学， 2002， 硕士

【摘要】 以RAPD技术分析长叶榧（Torreya jackii Chun）的遗传结构，主要包括：1、长叶榧RAPD反应条件的研究，确定总体积为15μl的长叶榧的最佳的RAPD反应体系为：50mmol／LKCl、10mmol／L Tris-HCl（pH9.0）、0.1％Triton-100、2nmol／μlMgCl₂、0.6nmol／μl dNTPs、0.75 u Taq酶、30ng引物以及100ng左右的基因组DNA。2、长叶榧的遗传多样性分析，分析了多态位点百分率（percentage of polymorphiC sites）、Nei氏基因多样性指数（Nei’s gene diversity index）、Shannon信息指数（Shannon’s Information index）、居群间的相似系数（genetic similarity index）和遗传距离（genetic distance）、遗传变异在居群间和居群内的分布（thepercentage of variance among and within population）及基因流（gene flow）。结论是：分布在群体间的遗传变异较分布在群体内的遗传变异小，说明该生物的分布范围越来越狭小。但长叶榧还保留了较高的遗传多样性：物种水平的Nei氏基因多样度指数达到0.2479，Shannon信息指数也达到了0.3807，而其物种水平的多态位点百分率高达86.93％。其基因流的期望值达1.6899，从理论上讲，若Nm＞1，群体间的基因交流可以防止遗传漂变造成的群体分化。聚类分析表明将石自然保护区的长叶榧居群与许坊水库的相似系数较大，而和许坊埂的相似系数较小，这和地理上将石自然保护区和许坊水库邻近，而许坊埂距前两者较远的事实相符。更多还原

【Abstract】 RAPD analysis on Torreya jackii Chun was studied in this thesis.- Two parts, I . study on RAPD reaction conditions for T. jackii: II. the analysis of genetic diversity on T. jackii by RAPD, were included. Several results were concluded: Firstly, the population of T. jackii was decreasing sharply and its living area was contracting, so the percentage of genetic variance among T. jackii populations was lower than that within its population; Secondly, its genetic diversity index was relatively high; Thirdly, according to its gene flow index, the population disintegration of the species could be prevented by genetic communication among populations of the species; Finally, the similar index between the populations from Jiangshi Nature Reserve and from Xufan Reservoir was higher than that between the populations from Jiangshi Nature Reserve and from Xufanggeng, corresponding with the fact that it is nearer between Jiangshi Nature Reserve and Xufan Reservoir than that between Jiangshi Nature Reserve and Xufanggeng.Various effectors of RAPD have been studied. The optimal RAPD reaction system for T. jackii was determined. It contained 50 mmol/L KCU 10 mmol/LTris-HCl (pH9. 0), 0. 1% Triton-100 2 nmolM MgCl2 0. 6 nraolM dNTPs, 0. 75 u TagDNA polymerase 30 ng primer and about lOOnggenomic DNA in a total volume of 15 /4.18 primers that were detected polymorphism were screened from 80 random primers to amplify the genome of 66 T. jackii samples from 3 populations. These primers detected 199 reproducible fragments among which there were 173 reproducible polymorphism fragments. The data was analyzed with three softwares: TFPGA POPGENE32 and AMOVA155 which are tools for molecular analysis.The percentage of polymorphic sites at species level was 86.93%, and they were 83% 68% and 80% at population level. Nei’ s gene diversity index was 0. 2479 at species level, and they were 0.2182, 0.1684 and 0.1881 at population level. The result of Shannon’ s information index analysis was correspondent with the result of Nei’ s gene diversity index analysis. So it was enlightened that T. jackii still had a high level of genetic diversity.The similar index between the T. jackii populations from Jiangshi Nature Reserve and Xufan Reservoir was higher than that between the populations from Jiangshi Nature Reserve and Xufanggeng. It was determined by geographical factors.The percentage of genetic variance among T. jackii populations was 30. 35%, and it was 69. 65% within T. jackii population. The result was correspondent with the resul ts of Gst and Fst analysis (the result of (7s t analysis was 0.2283, and that of Fst analysis was 0.2741). It was enlightened that the living space of the species was small and maybe still contracting.The gene flow index of the species was 1. 6899, it was suggested that the species still had the ability to recover from its danger situation through promoting the genetic communication among T. Jackii populations.更多还原