【摘要】 采用扩增片段长度多态性 (AFLP,Amplified fragment length polymorphism)方法对锥栗 (Castanopsischinensis)在3个不同群落亚种群的遗传分化进行了研究。研究地点位于广东省鼎湖山 ,3个群落分别是 :针叶林群落 ,针阔叶混交林群落 ,常绿阔叶林群落。采集的叶样进行 DNA提取、酶切、连接、PCR扩增后进行变性聚丙烯酰胺的凝胶电泳 ,银染后把所得带进行 1 /0标记。结果表明 ,四组引物对分别扩增出 2 7,2 0 ,3 3 ,3 9条带 ,其中分别有 1 5 ,1 5 ,1 8,2 6条是多态性带 ,说明其多样性较高。用 AMOVA(Analysis of molecularvariance)分析表明 75 .3 6%的遗传变异表现在种群内 ,2 4 .64 %的遗传变异表现在种群间 ,极显著 (P<0 .0 0 1 )。使用 Nei遗传距离进行了算术平均数的非加权成组配对法分析(UPGMA) ,其聚类结果表明常绿阔叶林群落亚种群和针阔叶混交林群落亚种群的种群聚合在一起。上述结果说明锥栗不同亚种群有不同的遗传多样性 ,种群间遗传分化较大。这是种群本身遗传特性的反映 ,并与群落演替密切相关 ,即不同群落微环境对种群遗传的影响更多还原

【Abstract】 The extent of genetic differentiation among populations has become a topic of increasing interest in the related spheres of ecology.However,relatively few studies were reported concerning population genetic differentiation following with community succession. Dinghu Mountain(112°30′39″-112°33′41″E,23°09′21″～23°11′30″N)is situated in Guangdong Province China,and belonging to the lower subtropics.According to community physiognomy,species composition and successional stage,three typical vegetation types are found:pioneer coniferous community,midsuccessional mixed coniferous evergreen broadleaved community and climax evergreen broadleaved forest.They coexist in Dinghu Mountain and make it ideal place for inversigating population genetic differentiation related to community succession. Then,this paper focused on species Castanopsis chinensis to study its genetic differentiation.For it no genetic study was reported before. C.chinensis is one of the heliphyte species in lower subtropics,and dominates at the altitude between 50～800m in Dinghu Mountain,China.As mid successional species,it can be found in coniferous community,mixed coniferous evergreen broadleaved community and evergreen broadleaved community. In May 1999,samples were collected from three communities above.The sample number for coniferous community was 10,for mixed coniferous evergreen broadleaved community 18,and for evergreen broadleaved community 20.Here,the individuals belonging to the same community composed a subpopulation. The distance between coniferous community and mixed coniferous evergreen broadleaved community was 600m,coniferous community and evergreen broadleaved community 800m,and mixed coniferous evergreen broadleaved and evergreen broadleaved community 350m. We confined our samples in their own communities,to reduce probability of confounding variable.A minimum distance separated the trees,>50m,from parent trees to avoid progeny of one parent trees. Recently,a proliferation of genome marker techniques is advanced,for example,RFLP(restriction fragment length polymorphism),RAPD(random amplified polymorphic DNA),DAF(DNA amplification fingerprinting),AP PCR(arbitrarily primed PCR).The drawback for all of these techniques is sensitive to the reaction condition and DNA quality.As a simple,cheap,efficient and informative tool,AFLP(amplified fragments length polymorphism)is used in our study.The abundance of genetic markers of AFLP allows for a more accurate genetic study in C.chinensis population. The PCR reaction products were analyzed in 5% denaturing polyacrylamide gels.After electrophoresis,silver staining was performed. Then,AFLP markers were scored for presence(1)or absence(0).Only polymorphic markers that could score unequivocally in all genotypes were induced in the anlysis below. The pairwise distances between genotypes were estimated using Euclidean distances,then were used in AMOVA(analysis of molecular variance,1.55)package to estimate the genetic differentiation among subopulations.Pairwise similarities of 1/0 data from all markers were also calculated between subpopulations using Nei’s genetic distance.The resultant similarity matrix was put into UPGMA(unweighted pair group with arithmetic average)cluster analysis with PHYLIP 3.5C. The results showed that four AFLP primer combinations yielded 27,20,33 and 39 AFLP bands respectively,in which 15,15,18,26 bands were polymorphic. AMOVA analysis revealed 75.36% of the variation occurred within subpopulations,24.64% of variation occurred among subpopulations with great significant p value(<0.05).Phist( st )was 0.246 with significance whith indicated 24.6% genetic differentiation among subpopulations. Nei’s genetic distance was calculated and used in cluster analysis,and the results showed subpopulation of coniferous community was separated from the other two subpopultions. With these genetic analysis,this paper obtained meaningful results in C.chinensis related to community succession. Previous researches suggested that for F st更多还原