來自動(dòng)物研究所科技信息中心的消息,，中國科學(xué)院動(dòng)物研究所分子生態(tài)學(xué)和進(jìn)化研究組的研究人員運(yùn)用分子生態(tài)學(xué)的研究手段,，從多個(gè)獨(dú)立微衛(wèi)星DNA位點(diǎn)對(duì)覆蓋飛蝗中國分布區(qū)的25個(gè)樣點(diǎn)的1300多個(gè)標(biāo)本進(jìn)行了綜合分析。這項(xiàng)研究成果一方面驗(yàn)證了飛蝗經(jīng)典分類的一些結(jié)論,，另一方面則指出了對(duì)由Boris Petrovitch Uvarov (1889-1970)（被學(xué)界譽(yù)為“蝗蟲之父”）在上世紀(jì)三十年代建立的關(guān)于東亞飛蝗的有關(guān)權(quán)威觀點(diǎn)進(jìn)行修正的必要性,。
飛蝗是一種重要農(nóng)業(yè)害蟲，具有很強(qiáng)的遷飛能力,，其分布區(qū)比任何其他蝗蟲都更廣闊,，幾乎覆蓋了東半球的整個(gè)溫、熱帶地區(qū),。然而，基于生物學(xué)或形態(tài)學(xué)差異,，飛蝗僅在中國就鑒定出了三個(gè)亞種,，而在世界范圍內(nèi)則存在至少九個(gè)亞種——這跟其遷飛能力是相矛盾的，學(xué)術(shù)界對(duì)此也一直存留爭議,。
張德興教授的研究團(tuán)隊(duì)運(yùn)用分子生態(tài)學(xué)的研究手段,，從多個(gè)獨(dú)立微衛(wèi)星DNA位點(diǎn)對(duì)覆蓋飛蝗中國分布區(qū)的25個(gè)樣點(diǎn)的1300多個(gè)標(biāo)本進(jìn)行了綜合分析。他們發(fā)現(xiàn),，盡管飛蝗具有很強(qiáng)的遷飛擴(kuò)散能力,，中國的飛蝗確實(shí)分為北方種群,、南方種群和西藏種群三個(gè)具有顯著遺傳差別的種群，但是與傳統(tǒng)認(rèn)識(shí)不同的是,，廣布于中國中,、東部的飛蝗并非東亞飛蝗，而是應(yīng)隸屬于亞洲飛蝗亞種,。他們的研究成果一方面驗(yàn)證了飛蝗經(jīng)典分類的一些結(jié)論,，另一方面則指出了對(duì)由Boris Petrovitch Uvarov (1889-1970)（被學(xué)界譽(yù)為“蝗蟲之父”）在上世紀(jì)三十年代建立的關(guān)于東亞飛蝗的有關(guān)權(quán)威觀點(diǎn)進(jìn)行修正的必要性。
該研究團(tuán)隊(duì)還進(jìn)一步分析了飛蝗在中國形成和維持三個(gè)具有顯著遺傳差別的種群的原因,，指出：歷史生物地理學(xué)因素可能是導(dǎo)致形成這三個(gè)地理種群的關(guān)鍵原因,，特別是更新世冰期-間冰期旋回事件，使得飛蝗種群退縮到不同的避難地并發(fā)生適應(yīng)性分化,，現(xiàn)今的種群是氣候和生態(tài)條件恢復(fù)后重新建群的結(jié)果,；而飛蝗中國北方種群很可能是在末次冰期后由中亞的避難地?cái)U(kuò)散而來。他們還指出,，盡管飛蝗的遷飛擴(kuò)散能力非常強(qiáng),，但適應(yīng)性差異使得三個(gè)飛蝗種群能夠維持它們目前的分布格局。這些關(guān)于中國飛蝗的研究結(jié)果無論對(duì)于飛蝗研究還是對(duì)中國的動(dòng)植物群體的譜系生物地理演化研究都具有重要意義,，例如,，它揭示出生物的演化歷史對(duì)于塑造具有很強(qiáng)擴(kuò)散能力的物種的種群分化和分布模式的重要性；又如,，鑒于我國東部地區(qū)的飛蝗和蒙新高原及東北的飛蝗共同組成北方種群,，因而共同構(gòu)成了一個(gè)地區(qū)間可進(jìn)行廣泛基因交流的遺傳群，在全球變化氣候逐漸變暖的趨勢下,，飛蝗有逐漸向北擴(kuò)散的可能,，東北地區(qū)將會(huì)逐步具有飛蝗大發(fā)生的所需要的必要?dú)夂驐l件；而相比之下,，南方種群（如海南的飛蝗）對(duì)于華北地區(qū)的影響則可能較小,。（生物谷Bioon.com）
生物谷推薦原始出處：
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.
