【作者】 张彩霞；

【导师】 刘新民；

【作者基本信息】 内蒙古师范大学 ， 动物学， 2008， 硕士

【摘要】 小驼嗡蜣螂Onthophagus gibbulus,隶属于鞘翅目Coleoptera金龟总科Scarabaeoidea金龟科Scarabaeidae嗡蜣螂属Onthophagus,以哺乳动物粪便为食。本文根据前人的研究及作者的采集观察,总结了内蒙古中部地区小驼嗡蜣螂的生物学特性,描述了成虫雄性生殖器及其幼虫形态特征,采用形态标记、RAPD分子标记技术,对内蒙古地区几种典型生境中的小驼嗡蜣螂种群的遗传多样性、以及与环境的关系进行了研究,研究结果如下:在内蒙古中部区7个种群的RAPD分析中,16条引物共扩增得到363条带,POPGENE分析结果表明,总多态位点比率为100%。小驼嗡蜣螂总的Nei’s基因多样度指数为0.280,总的Shannon多样性指数为0.433,表明小驼嗡蜣螂种群遗传多样性丰富;分子方差(AMOVA)分析表明,12.57%的变异存在于种群间,87.43%的变异存在于种群内,种群间的遗传分化系数(Gst)为0.158;Arlequin分析结果也显示小驼嗡蜣螂种群间的遗传分化系数FST较低,在0.050～0.18(0P>0.05)之间,基因流Nm在2.278～9.507之间,表明种群间存在广泛的基因交流。对采自内蒙古中、东部区的8个小驼嗡蜣螂地理种群的357头成虫标本的13项形态学指标的聚类分析结果表明,8个地理种群聚为两大支,中部区的7个种群聚为一支,东部区的1个种群为一支,即中部地区间小驼嗡蜣螂不同种群的形态特征较接近,而与东部区种群的形态差异较大。Mantel相关性检验发现在大的地理范围内,欧氏距离与相应的地理距离之间存在正相关关系,相关显著(P<0.05,1000次置换);判别分析中,建立了8个不同生境中种群的判别函数,判别准确率在26.2%～81.3%之间,综合判别率为44.3%。种群判别函数的二维点图中,中部区7个种群的判别中心比较接近,并与东部区种群的判别中心相距较远,这与聚类分析的结论一致。在内蒙古中部区小范围内,RAPD数据聚类分析结果表明,7个种群分为了两大支。形态标记聚类结果则显示7个种群可分为3个分支。两种研究结果均表明武川种群和察哈尔种群形成了稳定的一支。但Mantel相关性检验表明欧氏距离、遗传距离与地理距离之间并不存在显著的相关性。中部地区7个种群的形态数据所得的欧氏距离矩阵与RAPD所得遗传距离矩阵经Mantel相关性检验显示,相关性不显著(P>0.05,1000次置换),即形态特征的分化与RAPD数据所得的遗传分化之间的相关性不显著。就所研究的种群而言,3个多样性指数与海拔高度之间成正相关,但相关不显著;与降水量、1月份均温、7月份均温及≥10℃年积温之间均存在负相关关系,但不显著(P>0.05);与≥10℃年积温之间存在负相关关系,相关显著(P<0.05)。形态标记所得小驼嗡蜣螂种群间欧氏距离与所选6个环境因子的总分异之间经Mantel相关性检验显示,存在极显著(P<0.01)的相关关系。这些结果表明若干环境因子对小驼嗡蜣螂种群内遗传变异起一定的作用,其中≥10℃年积温对种群分化起主要作用。更多还原

【Abstract】 Onthophagus gibbulus belonged to Onthophagus, Scarabaeidae, Scarabaeoidea, Coleoptera. It was a coprophagous scarabs with mammal dung. In this study, its biological characters were summarized, characters of male genital and the external form of larva were described. Morphological Markers and RAPD molecular technique were applied to study the genetic diversity,and correlation between genetic and several entironment factors of O.gibbulus populations sampled from serevral typical habitats in the middle and eastern part of Inner Mongolia. Results as follow:Seven geographic O.gibbulus populations collected from the middle part of Inner Mongolia were analyzed by Random Amplification Polymorphism DNA (RAPD) molecular technique. RAPD amplification was conducted with 16 primers, Popgene software analyses indicated that 363 polymorphic loci were detected, with percentage of polymorphic loci (P) being 100%. The total Nei’s gene diversity (h) was 0.280, and Shannon’s information index (H) was 0.433, indicating a high level of genetic diversity of O. gibbulus; Analysis of molecular variance (AMOVA) demonstrated that the among-population component accounted for 12.57% of the total variation, while the within-populations component accounted for 87.43%, and the genetic differentiation coefficient (Gst) among the populations was 0.158; Arlequin software analysis demonstrated that the coefficient of genetic differentiation among the populations were low, between 0.050 and 0.180, and the gene flow value Nm among the populations were 2.278～9.507, which indicated a strong gene flow among the populations.Morphological data of O.gibbulus collected from eight populations in the middle and eastern part of Inner Mongolia, and 13 morphometric characters were measured from 357 adult specimens and the level of morphological similarity among sites was calculated using multivariate analysis techniques. The cluster analysis indicated that the 8 populations divided into two branches, seven populations from middle part was one branch, eastern population was another one. I.e., morphological variation level among populations of O.gibbulus from middle part was lower than that between middle and eastern populations. Mantel t-test revealed that in large geographical scale the populations’genetic variation was positively correlated with the geography distance. Discriminant analysis established the discriminant functions of these eight populations, and revealed that the percentage of discriminant were between 26.2%～81.3%, and total percentage of discriminant 44.3%. The centers of 2D-plots of discriminant functions of the middle part population were closer than that between middle and eastern populations. This result was congruent with cluster analysis.In the small geographical scale of middle part of Inner Mongolia, the cluster analysis based on RAPD dates showed the seven populations were divided into two branches. However, the cluster analysis based on morphometric dates showed the seven populations were divided into three branches. In both two analyses, Wuchuan and Chahaer populations clustered together. The Mantel-test indicated that in small geographical scale there was positive correlation between genetic variation and geography distance, but not significant. The correlation was not significant between Euclidean’s distance and Nei’s unbiased genetic distance of 7 different middle part populations by Mantel test. I.e., the populations’morphological differentiation has no correlation with the genetic variation.Mantel tests showed that there was significant positive correlation (P<0.01)between matrix of Euclidean’s distance of O.gibbulus poulations and matrix of six environment divergences, suggesting that natural selection of environment resulted in differentiation of O.gibbulus poulations. Correlation analysis of total populations show that the genetic diversity indexes was positively correlated with altitude, but not significant (P>0.05), and was negatively correlated with annual precipitation and temperature factors(≥10℃cumulative temperature in a year, mean temperature in January and mean temperature in July) but not significant (P>0.05), and was negatively correlated with≥10℃cumulative temperature in a year significantly (P<0.05). Summarizing,≥10℃cumulative temperature in a year was the major factor causing the genetic divergence of O.gibbulus poulations.更多还原