Jiang Xing-Fu, Cao Wei-Ju, Zhang Lei, Luo Li-Zhi
State Key Laboratory for Biology of Plant Diseases and Insect Pest, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Environ Entomol. 2010 Feb;39(1):232-42. doi: 10.1603/EN08315.
Genetic diversity within and among 11 geographic populations of the beet webworm Loxostege sticticalis across five provinces in the northern part of China were evaluated using amplified fragment length polymorphism (AFLP) analysis. Five AFLP primer combinations were used on 88 L. sticticalis samples from different locations, detecting a total of 384 polymorphic and 27 monomorphic fragments. Although extensive genetic diversity occurs among individuals from different geographic populations (P = 93.4%, h = 0.398, I = 0.572), the majority of the genetic diversity is within populations and not between populations (G(ST) = 0.196), which agrees well with the results of analysis of molecular variance (84% of the total genetic variation is within populations), indicating high gene flow (N(M) = 2.046) among natural populations, which are not genetically differentiated. L. sticticalis in northeastern China, northern China, and northwestern China are part of a single large metapopulation. Cluster analyses based on AFLP data were preformed to graphically show groupings between individuals and between populations. Individuals from the same region were not grouped together very well. Eleven subpopulations were clustered into six broad groups, and there was no significant correlation between geographic distance and genetic dissimilarity (r = 0.1236, P = 0.8512). Principle component analysis also indicated a lack of genetic differentiation between the 11 populations. These results indicated that, although high genetic variability existed among individuals, there was little genetic differentiation among geographic populations, which can be explained by the effects of long distance migration of the beet webworm in China and consequent gene flow.
利用扩增片段长度多态性（AFLP）分析，对中国北方五省11个地理种群的草地螟Loxostege sticticalis种群内和种群间的遗传多样性进行了评估。对来自不同地点的88份草地螟样本使用了5种AFLP引物组合，共检测到384个多态性片段和27个单态性片段。虽然不同地理种群个体间存在广泛的遗传多样性（P = 93.4%，h = 0.398，I = 0.572），但大部分遗传多样性存在于种群内而非种群间（G(ST) = 0.196），这与分子方差分析结果（84%的总遗传变异存在于种群内）高度一致，表明自然种群间存在较高的基因流（N(M) = 2.046），且这些种群没有遗传分化。中国东北、华北和西北的草地螟属于一个单一的大型集合种群。基于AFLP数据进行了聚类分析，以直观展示个体间和种群间的分组情况。来自同一地区的个体并未很好地聚在一起。11个亚种群被聚为6大类，地理距离与遗传差异之间没有显著相关性（r = 0.1236，P = 0.8512）。主成分分析也表明11个种群之间缺乏遗传分化。这些结果表明，虽然个体间存在较高的遗传变异性，但地理种群间几乎没有遗传分化，这可以用中国草地螟的远距离迁飞及其导致的基因流来解释。
