科研之友
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摘要
The native Hawaiian tree snail Achatinella sowerbyana has, along with its remaining congeners, experienced drastic population reductions in the past century. The species is endemic to O%26apos;ahu, and currently persists in fragmented wild populations and in a captive breeding facility at the University of Hawai%26apos;i at Manoa. We used seven microsatellite loci to examine genetic diversity and population structure, to look for genetic effects of population reductions, and to estimate current effective population sizes of four sampling locations on O%26apos;ahu, Hawai%26apos;i. We also sought to test the genetic similarity of the captive snails to the wild samples. Our results show low levels of inbreeding, but relatively low levels of genetic diversity. Bottleneck tests identified bottlenecks at each of the four populations, and current effective population sizes ranged from 9 to 68, indicating that continued reductions in genetic diversity are likely due to drift. There was measurable structure among populations, including significant F-ST values between all sampling locations, and two main clusters, each containing two populations. Attempts to assign the captive bred individuals to wild populations indicated they were more closely related to the southern populations, but that they were divergent from any of the wild populations. Our results indicate that, although introduced predators and habitat fragmentation still threaten A. sowerbyana, genetic concerns must also be addressed in managing this species. Strategies that retain the highest amount of genetic diversity and that are mindful of the population structure detected will provide A. sowerbyana the best chance for persistence.
- 出版日期2014-10
