DNA Barcodes Confirm the Taxonomic and Conservation Status of a Species of Tree on the Brink of Extinction in the Pacific

The taxonomic status of a single island, narrow range endemic plant species from Palau, Micronesia (Timonius salsedoi) was assessed using DNA barcode markers, additional plastid loci, and morphology in order to verify its conservation status. DNA barcode loci distinguished T. salsedoi from all other Timonius species sampled from Palau, and were supported by sequence data from the atpB-rbcL intergenic spacer region. Timonius salsedoi was only known from two mature individual trees in 2012. Due to its extremely narrow range and population size, it had previously been recommended to be listed as Critically Endangered Status under three separate IUCN Criteria. In 2014 a second survey of the population following a typhoon revealed that the only two known trees had died suggesting that this species may now be extinct. Comprehensive follow up surveys of suitable habitat for this species are urgently required.

本研究针对源自密克罗尼西亚帕劳的单一岛屿狭域分布特有植物物种Timonius salsedoi，采用DNA条形码(DNA barcode)标记、额外质体基因座及形态学特征对其分类学地位展开评估，以验证其保护等级。DNA条形码基因座可将T. salsedoi与帕劳地区采集的所有其他Timonius属物种区分开来，该结果得到了atpB-rbcL基因间隔区序列数据的支持。2012年时，该物种仅记录有2株成熟个体。鉴于其分布范围极窄且种群规模极小，此前已有建议依据三项独立的世界自然保护联盟（IUCN）红色名录评估标准将其列为极危等级。2014年，研究人员在台风过后对该种群开展二次调查时发现，仅存的两株已知个体均已死亡，这表明该物种可能已经灭绝。当前亟需针对该物种的适宜栖息地开展全面的后续调查工作。