Laboratory of Systematic Botany, Department of Crop Science, School of Plant Sciences, Agricultural University of Athens, Athens, Greece.
Genetics Laboratory, Department of Biotechnology, School of Applied Biology & Biotechnology, Agricultural University of Athens, Athens, Greece.
PLoS One. 2021 Feb 19;16(2):e0246706. doi: 10.1371/journal.pone.0246706. eCollection 2021.
Asperula naufraga is a rare and threatened obligate chasmophyte, endemic to Zakynthos island (Ionian islands, Greece). In this study, we provide a combined approach (including monitoring of demographic and reproductive parameters and study of genetic diversity) to assess the current conservation status of the species and to estimate its future extinction risk. The five subpopulations of A. naufraga were monitored for five years (2014-2018). Population size markedly fluctuated between 68-130 mature individuals during the monitoring period. The extent of occurrence (EOO) was estimated at 28.7 km2 and the area of occupancy (AOO) was 8 km2. Stage-structure recordings were similar for all subpopulations, characterized by high proportions of adult and senescent individuals, following a common pattern, which has been observed in other cliff-dwelling plants. Preliminary genetic analysis with SSRs markers revealed low heterozygosity within subpopulations and significant departure from H-W equilibrium, which combined with small population size suggest increased threat of genetic diversity loss. Our results indicate that the species should be placed in the Critically Endangered (CR) IUCN threat category, while according to Population Viability Analysis results its extinction risk increases to 47.8% in the next 50 years. The small population size combined with large fluctuations in its size, low recruitment and low genetic diversity, indicate the need of undertaking effective in situ and ex situ conservation measures.
海罂粟（Asperula naufraga）是一种罕见且受到威胁的专性裂生植物，仅分布于扎金索斯岛（爱奥尼亚群岛，希腊）。在这项研究中，我们采用了一种综合方法（包括监测人口和繁殖参数以及研究遗传多样性）来评估该物种的当前保护状况，并估计其未来的灭绝风险。我们对海罂粟的五个亚种群进行了五年（2014-2018 年）的监测。在监测期间，种群数量在 68-130 个成熟个体之间明显波动。发生范围（EOO）估计为 28.7 平方公里，占有面积（AOO）为 8 平方公里。所有亚种群的阶段结构记录都相似，特征是成年和衰老个体的比例很高，遵循一种常见模式，这种模式在其他悬崖栖息地植物中也观察到过。初步的遗传分析使用 SSR 标记显示亚种群内的杂合度较低，并且与 H-W 平衡显著偏离，这与小种群大小相结合表明遗传多样性丧失的威胁增加。我们的结果表明，该物种应被置于极危（CR）IUCN 威胁类别，而根据种群生存力分析结果，其在未来 50 年内的灭绝风险增加到 47.8%。小种群大小加上其大小的大幅波动、低繁殖力和低遗传多样性，表明需要采取有效的就地和迁地保护措施。
