| The Tibaten migratory locust: Locusta migratoria tibetensis Chen was one of the most important pests in Tibaten plateau. In recent years, it causes serious damage in Xizang Autonomous Region, southern part of Qinghai Provence and western part of Sichuan Provence in China. It has unique characteristics of morphological characteristics and genetic polymorphisms in the complex environment. At persent, most of the related reports were about its distribution, biological characteristics, cold-hardiness. However, the divergence of numeric characteristics and genetic structure of geographical populations have not been reported. In this thesis, numeric and genetic characteristics of different geographical populations have been studied systematically, The results were as follows:1. The gregarious and solitarious adults were significantly differentiated in color and morphology, but the difference between the phase gregarious and solitarious were depends on the morphological changes. There are significantly differences between morphometric prameters of geographical populations, and Coefficient of variation was smaller in gregarious geographical populations than the solitarious geographical populations.2. Morphometric indicators elytron length (E), posterior femur length (F), maximum width of head (C) and ratio E/F, F/C can be used as numeric parameters to analysis the relationships between geographical populations. The results of principal component analysis and hierarchical cluster analysis for gregarious geopopulations were similar, but there are a little difference for solitarious. The 9 gregarious geographical populations can be divided into three natural groups. The first group includes Baiba and Bamei geographical populations. The second group includes Pulan, Zhanang and Luoxu geographical populations. The third group includes Gaer, Xiangzi, Ritu and Naga geographical populations. And 16 solitarious geographical populations can be divided into five natural groups. The first natural group includes Chayu, Luhuo, Sangri and Rikaze geographical population. The second natural group includes Yigong and Milin geographical population; the third group was includes Luoxu, Xiangzi, Zhanang, Bamei and Naga geographical populations. The forth group includes Ganzi, Pulan and Gaer geographical population. And the fifth natural group includes Baiba geographical population.3. Among 11 pairs of primers, except primer LmIOZc9 and LmIOZc76, other nine pairs were polymorphism loci and could amplified 208 alleles. The average numbers of alleles and efficiency alleles of per locus were 20 and 11.77 respectively. The observed heterozygosity ranged from 0.351 (LmI-88) to 0.810 (LmIOZc26). The expected heterozygosity varied from 0.835 (LmI-88) to 0.946(LmIOZc29). The average heterozygosity of community was 0.669. The polymorphism information content varied from 0.810 (LmI-88) to 0.9521(LmIOZc29), and the average polymorphism information content was 0.902. The results showed an abundant genetic polymorphism of geographical populations of Locusta migratoria tibetensis.4. According to the genetic variations between geographical populations of L. m. tibetensis, the 14 geographical populations collected from the Tibetan plateau were divided into four groups. The first group includes Gaer, Ritu and Baiba geographical populations. The second group includes Xiangzi, Naga and Pulan geographical populations. The third group includes Luhuo, Ganzi, Bamei and Luoxu geographical populations. The fourth group was includes Rikaze, Zhanang, Sangri and Xiangchneg geographical populations.The study provides a theoretical basis for population occurrence and spread trends of L. m. tibetensis. It contributes an important reference to studing on biogeography of L. m. tibetensis and to researching and developmental of functional genes. The result also provides a clues and theories for study on population differentiation of L. m. tibetensis under the ecological and environmental strees.
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