| 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 because it can examine a large amount of loci at the genome by use of many primers.It is advantageous for its high 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. However, up to date RAPD has been used widely in the studies of Orthoptera, especially Acridoidea insects. Because the RAPD method fits the law of Mendel genetics, which is used complementarily for the population genetics studies in a comprehensive way.The locust of Acridoidea represents a large insect group that can be found in various ecological habitats. The insects have different ecotypes and geographic populations as a result of feeding habits and the adaptations to each environment. The genetic divergence among the populations occurs during the long-time isolation and evolution. This research, by use of RAPD technique, examined the genetic structure and divergence among the natural populations of the locusts (Locusta migratoria manilensis) collected from different locust breeding areas. The oriental migratory locust is a major agricultural pest due to its huge consumption of crops, and more importantly its periodic massive outbreaks. This studies have rendered abundant value for the research in the genetics population of locust in China.Random amplified polymorphic DNA (RAPD) provides a powerful tool for investigation of genetic variation in natural and domesticated populations. We described the genetic variation of 9 natural populations (collected from Shanxi Linyi, Shanxi Yongji, Jiangsu Peixian, Henan Zhongmou, Hebei Pingshan, Hebei Huanghua, Tianjin Beidagang, Liaoning Huludao in China)of Locusta migratoria manilensis (Meyen) and Locusta migratoria migratoria (Linnaeus) from Xinjiang Wulumuqi. Eleven arbitrary 10 base-pair primers produced 163 clear and reproducible amplification bands, 161 bands of which were polymorphic ones. The total percentage of polymorphisms bands was 98.77%. Different primers had different RAPD loci and percentage of amplification bands among different populations. The RAPD patters demonstrated consistent polymorphisms in different populations and subspecies.Based on the presence/absence of bands, Shannon's index, Nei's index and a genetic distance matrix were analyzed. The results showed that higher genetic diversity existed within Locusta migratoria manilensis (Meyen) populations. Shanxi-Linyi population had higher genetic diversity, Shannon's index and Nei's index was 0.2767 and 0.1896 respectively, while Henan-Zhongmou population had the lowest level, Shannon's index and Nei's index was 0.1648 and 0.1109 respectively. Partitioning of the genetic diversity of 8 populations of Locusta migratoria manilensis estimated by Shannon's index indicated that 57.10% of the variation occurred within populations and 42.90% of the variation existed among populations, gene differentiation coefficient estimated by Nei's index was 40.10% which is almost identical with Shannon's index.The dendrogram based on Nei's genetic distance of RAPD markers was constructed using NJ indicated high similarities within-population. The nine populations of Locusta migratoria were divided into three big branches. Shanxi-linyi population and Shanxi-Yongji population were clustered into one branch, Henan-Zhongmou population and Jiangsu-Peixian population were clustered into one branch, the two branches were clustered together, then Liaoning-Huludao population clustered with them. Heibei-Pingshan population and Hebei-Huanghua population were clustered into one branch, whereas Tianjin-Beidagang population was clustered with Hebei population before clustered with Huludao population. However, Xinjiang-Wulumuqi population was clustered with them finally. These data showed allpopulation was clustered with them finally. These data showed all populations can be distinguished with RAPD markers, Linyi population was closely related to Yongji poulation, Pingshan population was closely related to Huanghua population, nevertheless all the eight populations of Locusta migratoria manilensis (Meyen) had far genetic distance with Locusta migratoria migratoria (Linnaeus).The mean Nei's genetic distance and genetic identity between them were 0.1551 and 0.8567 respectively, whereas the mean Nei's genetic distance and genetic identity among Locusta migratoria manilensis (Meyen) populations were 0.2680 and 0.7651 respectively. The mean genetic distance between them and among them by use of mantel-test were 0.2298 and 0.3905 respectively, whereas the mean genetic distance among Locusta migratoria manilensis (Meyen) populations and Locusta migratoria migratoria (Linnaeus) by use of mantel-test were 0.4671.The result showed the similarity among different populations is higher than that among species.The Mantel test is used to determine if a correlation exists between two matrices of genetic distance and geographic distance. Genetic distance of 8 populations of Locusta detected with Mantel test was r<0.7 that showed cophenetic correlation measured very pool fit for genetic analysis. The cophenetic correlation of genetic distance and geographic distance was r = 0.6278, there seems not to be a tendency of correlations between the genetic and geographic distance among 8 different populations. The results also showed that genetic divergence of eight natural populations of Locusta migratoria manilensis (Meyen) did not correspond to geographic distance and genetic distance.The eight oriental migratory locust we studied can been divided into four areas according to the geography and the breeding habitats: HebeiPingshan, JiangsuPeixian and TianjinBeidagang belonged to the lake -shooed areas; ShanxiLinyi and HennanZhongnou belonged to the river flood areas; Hebei Huanghua and LiaoningHuludao belonged to the seacoast areas; ShanxiYongji belonged to the land plain flood areas. From the eight...
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