秦岭地区菜粉蝶遗传多样性及种群分化研究

【作者】 李建锋；

【导师】 许升全；

【作者基本信息】 陕西师范大学 ， 动物学， 2008， 硕士

【摘要】 菜粉蝶Pieris rapae(Linnaeus,1758)广泛分布于中国大部分地区;整个北温带,包括美洲北部一直到印度的北部。由于食性及环境条件的适应,形成了不同的生态型和自然地理种群,长期隔离和演化,同种菜粉蝶不同种群之间逐渐产生了一定的遗传分化。秦岭是中国动物地理区划中古北东洋两界的分界线,对秦岭地区的菜粉蝶的遗传多样性进行分析,能够为研究我国菜粉蝶的遗传多样性和动物地理演化提供理论依据。随机扩增多态DNA技术(Random Amplified Polymorphic DNA,简称RAPD)是二十世纪90年代以PCR技术基础发展起来的一项DNA分子多态检测技术,以一系列不同随机排列的碱基序列(单链寡核苷酸为引物)对所研究的基因组DNA进行PCR扩增。该技术能在没有任何遗传背景的情况下,对物种基因组进行DNA多态性分析。它不但能通过众多的引物检测大量的基因位点,且具有高效、快速、样品用量少和对材料要求不高等优点,目前已广泛用于动植物的遗传多样性研究中。用RAPD技术研究了菜粉蝶不同地理种群的遗传多样性,从60条随机引物中筛选出11个随机引物对10个菜粉蝶种群的60个个体的DNA样本进行了RAPD分析,共获得77个清晰稳定的位点,共有条带13条,多态位点共计64个,总的多态位点百分率为83.12%。不同引物在不同种群中所检测出的RAPD位点及多态性百分率不同。Shannon信息指数对RAPD数据的分析表明;本研究中的菜粉蝶种群存在较高的遗传多样性,其中,遗传多样性最高的为长安种群(1.5399),遗传多样性最低的是菜粉蝶延安种群群(0.8466)。同时,菜粉蝶种群间出现一定程度的遗传分化,由Shannon信息指数估算的种群遗传分化系数为56.73%,地理距离大小、隔离带、生境是造成这种结果的原因,造成菜粉蝶的生存瓶颈,从而分化成不同的种群。用UPGMA法对菜粉蝶种群进行聚类分析,结果显示:菜粉蝶留坝种群和菜粉蝶长安种群遗传距离较近,先聚为一簇,菜粉蝶南阳种群和它们的关系较近,菜粉蝶柞水种群与前面三个种群的亲缘较近,菜粉蝶商洛种群与前面的四个种群的亲缘关系较近;菜粉蝶三门峡种群和菜粉蝶洛阳种群亲缘关系较近,宁强种群与它们的遗传关系近;菜粉蝶安康种群和菜粉蝶延安种群的遗传关系较近。由Nei’s遗传一致度和遗传距离可以看出,菜粉蝶10个种群遗传一致度在0.8945～0.7011,遗传距离在0.1182～0.3300,遗传形似性最高的是菜粉蝶延安种群和菜粉蝶安康种群0.8945,遗传相似性最低的是菜粉蝶延安种群和菜粉蝶宁强种群0.7011,菜粉蝶不同种群之间存在一定的差异。同时也说明了由Shannon信息指数估算的种群遗传分化系数57.98%是中性的。采用Between-group linkage法对雄性菜粉蝶9个形态测量特征的聚类分析显示:菜粉蝶宁强种群和菜粉蝶留坝种群属于同一个地理宗;菜粉蝶安康种群和菜粉蝶商洛种群为一个地理宗,与菜粉蝶长安种群形态相似,与前面两个种群遗传变异接近;菜粉蝶洛阳种群和菜粉蝶三门峡种群为一个地理宗,在遗传变异程度上依次菜粉蝶柞水种群、菜粉蝶延安种群、菜粉蝶南阳种群接近。数量分类和RAPD聚类分析基本符合秦岭山脉和黄土高原对菜粉蝶的阻碍作用。更多还原

【Abstract】 Cabbage white butterfly(Pieris rapae) is widely distributed in China,whole the north temperate zone(from South America to Southern India).The feeding habits and adapt to environmental conditions result in many ecological and geographical populations,by long-time isolation and evolution,populations,cabbage butterfly populations gradually got a certain degree of genetic difference.Qinling Mountains is Palaearctic--Oriental boundary of China and world zoogeographical division.The analysis on P.rapae genetic diversity in Qinling Mountains can offer some theoretical basis for P.rapae genetic diversity and the zoogeographical division of China.The Random Amplified Polymorphic DNA(RAPD) technique is a method for examining the DNA polymorphism developed in 1990s.Based on PCR technology,it uses the single-stranded oligonucleotide of random sequence as primer to amplify the genomic DNA.The method is favored bacause it can examine a large amount of loci at the genome by use of many primers.It is advantageous for its haigh efficiency,quickness,small sample quantity and less requirements for sample quality,which resulted in its broad applications in the genetic fields of Botany,Zoology and other Subjects.In the study on genetic diverty of different P.rapae different geography populations,11 RAPD primers from 60 random primers,and 10 populations,60 individuals are used.The results show 77 clear and reproducible amplification bands,of which,64 bands are polymorphic ones.The total percentage of polymorphisms bands is 83.12%.Different primers have different RAPD loci and percentage of amplification bands among different populations.Based on the presence/absence of bands,Shannon’s index shows that there are higher genetic diversity existing within P.rapae populations.Chang’an populatin has highest genetic diversity,the Shannon’s index is 1.5399. Sanmenxia population has the lowest level,the Shannon’s index is 0.8466.56.73%of the variation exists among populations.But little distinctness in morphology.Population differentiaton is the reason that is Geography distance,isolation and habitat,pesticide is likely to lead to pieris rapae Survival bottleneck.We did cluster analysis of all individual with genetic distance of pieris rapae by UPGMA.The result showed that:Liuba populations and Chang’an populations was close and shared a cluster,and Nanyang populations had close relative with the two above,Zhashui populations had close relative with the three above,Shangluo populations had close relative with the four above;pieris rapae Sanmenxia populations and Luoyang populations had close relaionship,and Ningqiang populations had close relationship with them;Pieris rapae Ankang populations and Yan’an populations had close relative.It might be related with the geographical distance,isolated area and ecological environment of Pieris rapae habitat.From the Nei’s genetic identity and genetic distance,we could see that,the genetic identity and genetic distance of 10 Pieris rapae populations was 0.8945～0.7011 and 0.1182～0.3300.Pieris rapae Ankang populations and Yah’an populations’ genetic identity is highest,Pieris rapae Ningqiang populations and Yan’an populations’ genetic identity is lowest there were differences among different Pieris rapae populations.This result showed that the populations genetic differentiation coefficients 57.98%estimated by shannon information index was neutral.Cluster analysis on nine morphological charachers of male Pieris rapae in showed that,Pieris rapae Ningqiang populations and Liuba populations belonged to one geographical race;Pieris rapae Ankang populations and Shangluo populations belonged to one geographical race,which is morphologically similar with Chang’an populations and had close genetic variation with the two populations above;pieris rapae Luoyang populations and Sanmenxia populations belonged to one geographical race.It is in turn closed to Zhashui populations,Sanmenxia populatins and Nanyang populations on degree of Genetic variation.Numerical taxonomy and RAPD cluster accorded with the hindering effect of Qinling Mountains and the Loess Plateau to Pieris rapae.更多还原