大连长山岛玫瑰（Rosa rugosa Thunb.）种群的遗传多样性和遗传结构的初步研究

【作者】 翟雯；

【导师】 王仁卿；

【作者基本信息】 山东大学 ， 生态学， 2007， 硕士

【摘要】 玫瑰（Rosa rugosa Thunb．）是国家二级保护植物，是蔷薇科观赏植物天然的种质资源，具有重要的经济和生态学价值。由于人类活动对环境的破坏，使大连长山岛原有的大片玫瑰种群片断化，使其遗传多样性和遗传结构受到严重影响。本文以大连长山岛的玫瑰种群为研究对象，选取了17个丛（CSD1～CSD 17），148株样品，用RAPD标记对种群遗传多样性和遗传结构进行分析，并讨论了该种群受威胁的原因，提出了相应保护对策。本文通过14个随机引物共扩增到162个显性位点，其中多态位点148个，4个位点表现出丛的特异性；丛内多态位点百分比（P）的平均值为22.59％，平均每个位点的有效等位基因数（Ne）为1.1387，丛内Nei’s基因多样性指数（H）为0.0803，这在以克隆繁殖为主的植物中是比较低的。种群内多态位点百分比（P）达91.36％，基因多样性指数（H）为0.2690，Shanon信息指数（I）是0.4412，这说明大连上山岛玫瑰种群具有比较高的遗传多样性。丛大小与丛内多态位点百分比（P）、Shannon信息指数（Ⅰ），呈显著正相关。仅在一个丛检测到基因型完全相同的植株。对种群遗传结构和遗传分化的研究结果表明，各位点在丛间基因分化度(G_ST)的波动范围是0.0141～0.9743，在各位点分化程度差别很大，平均值为0.6954：丛间基因流（Nm）波动范围为0.0000～34.9826，平均值为0.2190，远小于1，说明丛间基因交流较小，遗传漂变较大。由遗传一致度和遗传距离的无偏差统计表明，在17个丛中，最小的遗传距离是0.1006，在丛CSD4和CSD5之间；最大的遗传距离是0.3803，在丛CSD3和CSD16之间；Mental检测表明遗传距离与空间距离呈明显正相关。由哈-温平衡检验结果分析，占总位点数的80.25％，说明有80.25％的位点严重偏离随机交配。与其它地区种群相比，大连长山岛野生玫瑰种群分布范围较大，生境相对较好，遗传多样性水平高，但在部分海岸线也存在生境的破坏及退化，导致玫瑰分布区片断化，种群规模减少，进而可能会导致在遗传漂变的作用下使其遗传多样性逐渐丧失。建议对其采取适当的就地措施，规划保护区，保护海岸植被与生境，促进种群恢复，并辅以人工保育以加大丛间的基因流。更多还原

【Abstract】 Wild Rosa rugosa thunb. has been ranked in the second protected plants and its germplasm, economic and ecological importance can’t be ignored. But more and more disturbance from human beings lead to make the habitats of Wild Rosa rugosa fragmental and Wild Rosa rugosa distributed in the unsuccessively habitats. Corresponding to this, the genetic structure and diversity of Wild Rosa rugosa have been seriously influenced which put them into dangerous situation. In the fragmental habitats of Wild Rosa rugosa of Changshan island of Dalian city, 17 clusters（CSDl-CSD17） of Wild Rosa rugosa have been selected to be put in the experiment and their genetic structure and diversity in the fragmental habitats have been analyzed by RAPD. combined with fragmental traits and reproduction traits of Wild Rosa rugosa clusters, the experiment conclusion has been well interpreted and protection methods have been advanced.162 loci were amplified by RAPD, of which 148 loci （91.36%） were polymorphic and 4 loci were specific , 12 loci were monomorphic to some clusters. The average of P （percents of polymorphic loci） within clusters was 22.59%. The average of N_e （number of efficient allele） was 1.1387. The average of H （expected heterozygosity） within clusters was 0.0803.Shannon index is 0.1196. It’s very low among clonal plants. The average of P （percents of polymorphic loci） within the population is 91.36%, H （expected heterozygosity） and / （Shannon index） are 0.2690 and 0.4412. There was great genetic variation in the population. Percent of polymorphic loci and Shannon index was positively correlative with the sample size and sample area ;Percent of polymorphic loci （F） and Shannon information index is positively correlative with the sample size. There are only one cluster have found clonal ones among 17 clusters.G_STGenetic divergence) of all RAPD loci among clusters was varied from 0.0141-1.0000.It’s very different from all RAPD loci. The means of G_ST（Genetic divergence） was 0.6954.N_m （gene flow） was varied from 0.0000³4.9826.The means of N_m（gene flow） was 0.2190, which was greatly less than 1, so there was serious genetic drift within and among clusters.From Neis’s unbiased measures of I （genetic identity） and D （genetic distance） by RAPD, the shortest genetic distance was between CSD4 and CSD5, which was 0.1006. The longest genetic distance was 0.3803 just between CSD3 and CSD16. Chi-square proof-test of all RAPD loci among clusters indicated that 80.25% of loci were prominently departure from Hardy-Winbergii equilibrium. Genetic identity was positively correlative with the space distance through Mental test.Compared with other populations of R. rugosa Thunb, R. rugosa Thunb in Changshan island of Dalian city have great genetic variation, but the habitat have been destroyed and degenerate in some area, which may result in the fragmentizing of the habit and the decrease of population genetic variation. The habitats should be restored to protect plants and habit in the coast and increase the population size to decrease the genetic differentiation among clusters, combined with manpower methodto hasten the exchange of gene flow.更多还原