五条蚋(Simulium quinquestriatum)不同地理种群遗传多样性的ISSR标记研究

Genetic Diversity of Different Geographical Populations of Simulium quinquestriatum Based on ISSR Analysis

为阐明五条蚋(S.quinquestriatum)不同地理种群的遗传多样性,应用ISSR技术对我国五条蚋8个地理种群的遗传多样性及其分化进行了研究分析。构建了中国五条蚋8个种群160个体的ISSR指纹图谱。8条引物扩增出111条ISSR条带,其中96条为多态性条带,占总扩增条带数的86.47%,每个种群显示了各自独特的ISSR图谱。ISSR标记的遗传多样性分析结果表明:五条蚋在物种水平表现出较高的遗传多样性(P=86.4%,A=1.991 0±0.094 9,AE=1.553 2±0.334 5,H=0.323 1±0.157 9,I=0.484 7±0.203 7);在种群水平表现出较低的遗传多样性(P=78.37%,A=1.492 1±0.499 7,AE=1.316 6±0.370 0,H=0.180 1±0.206 6,I=0.265 5±0.295 0);分子方差(AMOVA)分析结果表明五条蚋种群间的遗传分化为59%,种群内部的遗传分化程度为41%;种群间的遗传分化系数(Gst)为0.59,种群间基因流(Nm)为0.347 5。说明五条蚋不同地理种群间遗传分化程度高,地理屏障(高山和平原等)以及栖息地片段化是导致其遗传分化形成的主要因素。

In this paper, the genetic diversity of geographical populations of S. quinquestriatum from China was investigated with ISSR method using eight selective primers in order to clarify thegenetic diversity of eight different geographic populations of S. quirutuestriaturn. Establishment of ISSR fingerprint of S. quinquestriatum from eight populations of 160 individuals in this study. The results showed that total 111 bands were generated, of which 96 bands were polymorphic hands （ the percentage of polymorphic band, P= 86.47 % ） . The characteristic ISSR pattern for each individual was detected. S. quinquestriatum displayed the higher degree of genetic diversity at the species level （ P=86.4%, A=1.991 0 ± 0.094 9, AE=1.553 2 ± 0.334 5, H=0.323 1 ± 0.157 9, I=0.484 7 ± 0.203 7 ） than the population level （ P=78.37%, A=1.492 1 ± 0.499 7, AE=1.316 6 ± 0.370 0, H=0.180 1 ± 0.206 6, I=0.265 5 ± 0.295 0 ） . Results of AMOVA analysis demonstrated that the among-population component had a high degree which accounted for 59% of the total genetic differemiation ; while the within-population component accounted for 41%. The gene flow that among-population is 0.347 5. It is indicated that the main factors for the high degree of genetic differentiation among different geographic populations of S. quinquestriatum are geographic barrier （ mountains and plains ） and habitat fragmentation.