Bonizzoni M, Guglielmino C R, Smallridge C J, Gomulski M, Malacrida A R, Gasperi G
Dipartimento di Biologia Animale, Universita' di Pavia, Piazza Botta 9, I27100 Pavia, Italy.
Mol Ecol. 2004 Dec;13(12):3845-55. doi: 10.1111/j.1365-294X.2004.02371.x.
As a result of their rapid expansion and large larval host range, true fruit flies are among the world's most important agricultural pest species. Among them, Ceratitis capitata has become a model organism for studies on colonization and invasion processes. The genetic aspects of the medfly invasion process have already been analysed throughout its range, with the exception of Australia. Bioinvasion into Australia is an old event: medfly were first captured in Australia in 1895, near Perth. After briefly appearing in Tasmania and the eastern states of mainland Australia, medfly had disappeared from these areas by the 1940s. Currently, they are confined to the western coastal region. South Australia seems to be protected from medfly infestations both by the presence of an inhospitable barrier separating it from the west and by the limited number of transport routes. However, numerous medfly outbreaks have occurred since 1946, mainly near Adelaide. Allele frequency data at 10 simple sequence repeat loci were used to study the genetic structure of Australian medflies, to infer the historical pattern of invasion and the origin of the recent outbreaks. The combination of phylogeographical analysis and Bayesian tests showed that colonization of Australia was a secondary colonization event from the Mediterranean basin and that Australian medflies were unlikely to be the source for the initial Hawaiian invasion. Within Australia, the Perth area acted as the core range and was the source for medfly bioinvasion in both Western and South Australia. Incipient differentiation, as a result of habitat fragmentation, was detected in some localized areas at the periphery of the core range.
由于其迅速扩张以及幼虫寄主范围广泛，实蝇是世界上最重要的农业害虫种类之一。其中，地中海实蝇已成为研究定殖和入侵过程的模式生物。除澳大利亚外，地中海实蝇入侵过程的遗传方面已在其整个分布范围内进行了分析。生物入侵澳大利亚是一个由来已久的事件：1895年在珀斯附近首次在澳大利亚捕获到地中海实蝇。在短暂出现在塔斯马尼亚岛和澳大利亚大陆东部各州后，到20世纪40年代地中海实蝇已从这些地区消失。目前，它们仅限于西部沿海地区。南澳大利亚似乎因存在将其与西部隔开的不适宜生存的屏障以及运输路线数量有限而免受地中海实蝇侵扰。然而，自1946年以来已发生多次地中海实蝇疫情爆发，主要在阿德莱德附近。利用10个简单序列重复位点的等位基因频率数据来研究澳大利亚地中海实蝇的遗传结构，推断入侵的历史模式以及近期疫情爆发的起源。系统发育地理学分析和贝叶斯检验相结合表明，澳大利亚的定殖是来自地中海盆地的二次定殖事件，并且澳大利亚地中海实蝇不太可能是夏威夷最初入侵的源头。在澳大利亚境内，珀斯地区是核心分布区，是西澳大利亚和南澳大利亚地中海实蝇生物入侵的源头。在核心分布区外围的一些局部地区检测到由于栖息地破碎化导致的初始分化。
