来自动物研究所科技信息中心的消息，中国科学院动物研究所分子生态学和进化研究组的研究人员运用分子生态学的研究手段，从多个独立微卫星DNA位点对覆盖飞蝗中国分布区的25个样点的1300多个标本进行了综合分析。这项研究成果一方面验证了飞蝗经典分类的一些结论，另一方面则指出了对由Boris Petrovitch Uvarov (1889-1970)（被学界誉为“蝗虫之父”）在上世纪三十年代建立的关于东亚飞蝗的有关权威观点进行修正的必要性。
飞蝗是一种重要农业害虫，具有很强的迁飞能力，其分布区比任何其他蝗虫都更广阔，几乎覆盖了东半球的整个温、热带地区。然而，基于生物学或形态学差异，飞蝗仅在中国就鉴定出了三个亚种，而在世界范围内则存在至少九个亚种——这跟其迁飞能力是相矛盾的，学术界对此也一直存留争议。
张德兴教授的研究团队运用分子生态学的研究手段，从多个独立微卫星DNA位点对覆盖飞蝗中国分布区的25个样点的1300多个标本进行了综合分析。他们发现，尽管飞蝗具有很强的迁飞扩散能力，中国的飞蝗确实分为北方种群、南方种群和西藏种群三个具有显著遗传差别的种群，但是与传统认识不同的是，广布于中国中、东部的飞蝗并非东亚飞蝗，而是应隶属于亚洲飞蝗亚种。他们的研究成果一方面验证了飞蝗经典分类的一些结论，另一方面则指出了对由Boris Petrovitch Uvarov (1889-1970)（被学界誉为“蝗虫之父”）在上世纪三十年代建立的关于东亚飞蝗的有关权威观点进行修正的必要性。
该研究团队还进一步分析了飞蝗在中国形成和维持三个具有显著遗传差别的种群的原因，指出：历史生物地理学因素可能是导致形成这三个地理种群的关键原因，特别是更新世冰期-间冰期旋回事件，使得飞蝗种群退缩到不同的避难地并发生适应性分化，现今的种群是气候和生态条件恢复后重新建群的结果；而飞蝗中国北方种群很可能是在末次冰期后由中亚的避难地扩散而来。他们还指出，尽管飞蝗的迁飞扩散能力非常强，但适应性差异使得三个飞蝗种群能够维持它们目前的分布格局。这些关于中国飞蝗的研究结果无论对于飞蝗研究还是对中国的动植物群体的谱系生物地理演化研究都具有重要意义，例如，它揭示出生物的演化历史对于塑造具有很强扩散能力的物种的种群分化和分布模式的重要性；又如，鉴于我国东部地区的飞蝗和蒙新高原及东北的飞蝗共同组成北方种群，因而共同构成了一个地区间可进行广泛基因交流的遗传群，在全球变化气候逐渐变暖的趋势下，飞蝗有逐渐向北扩散的可能，东北地区将会逐步具有飞蝗大发生的所需要的必要气候条件；而相比之下，南方种群（如海南的飞蝗）对于华北地区的影响则可能较小。（生物谷Bioon.com）
生物谷推荐原始出处：
BMC Evolutionary Biology 2009, 9:144doi:10.1186/1471-2148-9-144
Unexpected relationships of substructured populations in Chinese Locusta migratoria
De-Xing Zhang1,2 , Lu-Na Yan1,4 , Ya-Jie Ji1 , Godfrey M Hewitt3 and Zu-Shi Huang1
1 State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
2 Center for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China
3 School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
4 Current address: College of Biological Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, Hebei 050018, PR China
Background
Highly migratory species are usually expected to have minimal population substructure because strong gene flow has the effect of homogenizing genetic variation over geographical populations, counteracting random drift, selection and mutation. The migratory locust Locusta migratoria belongs to a monotypic genus, and is an infamous pest insect with exceptional migratory ability – with dispersal documented over a thousand kilometers. Its distributional area is greater than that of any other locust or grasshopper, occurring in practically all the temperate and tropical regions of the eastern hemisphere. Consequently, minimal population substructuring is expected. However, in marked contrast to its high dispersal ability, three geographical subspecies have been distinguished in China, with more than nine being biologically and morphologically identified in the world. Such subspecies status has been under considerable debate.
Results
By multilocus microsatellite genotyping analysis, we provide ample genetic evidence for strong population substructure in this highly migratory insect that conforms to geography. More importantly, our genetic data identified an unexpected cryptic subdivision and demonstrated a strong affiliation of the East China locusts to those in Northwest/Northern China. The migratory locusts in China formed three distinct groups, viz. (1) the Tibetan group, comprising locusts from Tibet and nearby West China high mountain regions; this is congruent with the previously recognized Tibetan subspecies, L. m. tibetensis; (2) the South China group, containing locusts from the Hainan islands; this corresponds to the Southeast Asia oriental tropical subspecies L. m. manilensis; (3) the North China group, including locusts from the Northwest and Northern China (the Asiatic subspecies L. m. migratoria), Central China and Eastern China regions. Therefore, the traditional concept on Locusta subspecies status established from Uvarov in 1930s needs to be revised. The three groups of locusts probably have separate evolutionary histories that were most likely linked to Quaternary glaciations events, and derived from different ancestral refugial populations following postglacial expansions.
Conclusion
The migratory locust populations in China have differentiated into three genetically distinct groups despite high dispersal capability. While this clarified long-standing suspicions on the subspecific diversification of this species in China, it also revealed that the locusts in the vast area of East China are not the oriental subspecies but the Asiatic subspecies, an unexpected substructuring pattern. The distribution pattern of the three locust groups in China may be primarily defined by adaptive differentiation coupled to Quaternary glaciations events. Our results are of general significance both for locust research and for phylogeographical study of flora and fauna in China, illustrating the potential importance of phylogeographical history in shaping the divergence and distribution patterns of widespread species with strong dispersal ability.
