Population genetic suggestions to offset the extinction ratchet in the endangered Canarian endemic Atractylis preauxiana (Asteraceae)
| 详细信息 | 推荐本文 | |
- 作者：Juli Caujap茅-Castells ; Jos茅 Naranjo-Su谩rez ; Isabel Santana ; Mario Baccarani-Rosas ; Nereida Cabrera-Garc铆a ; Manuel Marrero ; Eduardo Carqu茅 and Ricardo Mesa
- 关键词：Atractylis preauxiana ; Canary Islands ; Endemic ; RAPDs ; Conservation ; Fragmentation ; Extinction
- 刊名：Plant Systematics and Evolution
- 出版时间：July, 2008
- 出版年：2008
- 期刊代码：216_0378-2697
- 类别：bio
- 卷：273
- 期：3-4
- 页码：191-199
- 数据来源：sp
摘要
We examined the levels and apportionment of genetic variation of the 11 known subpopulations of Atractylis preauxiana at 95 RAPD loci to help streamline a conservation strategy for this Canarian endemic taxon, which is in a critical situation because of the constant exposure of plants to intensive, uncontrolled anthropic action in the last few decades. Our results revealed low genetic variation levels that match with the general picture of demographic and habitat degradation that this taxon is undergoing. Although geographic isolation between Tenerife and Gran Canaria is an effective barrier to gene flow, genetic heterogeneity within islands is also substantial, plausibly due to the negative impact of fragmentation on genetic variation. Our genetic results, together with declining population sizes, poor seedling survival, and recent population extinctions, compellingly indicate that A. preauxiana is undergoing an extinction ratchet, whereby every further local extinction will add up to the probability of total species’ extinction. Our genetic results suggest that mitigating the deleterious consequences of this effect entails urgent mixed reinforcements of all sub-populations with sub-populations from the same island and urgent translocation of the two sub-populations from Tenerife that are doomed to extinction to ecologically suitable areas, together with seed collection and preservation in a convenient ex situ banking facility.