Dickinson Leta, Noble Hilary, Gardner Elliot, Puad Aida Shafreena Ahmad, Zakaria Wan Nuur Fatiha Wan, Zerega Nyree J C
Plant Biology and Conservation, Northwestern University, Evanston, IL, United States of America.
The Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, IL, United States of America.
PeerJ. 2020 Sep 21;8:e9897. doi: 10.7717/peerj.9897. eCollection 2020.
Limestone karsts of Southeast Asia can harbor high levels of endemism, but are highly fragmented, increasingly threatened, and their biodiversity is often poorly studied. This is true of the Padawan Limestone Area of Sarawak, Malaysia, home to the endemic the closest known wild relative of two important and underutilized fruit tree crops, jackfruit () and cempedak (). Identifying and conserving crop wild relatives is critical for the conservation of crop genetic diversity and breeding. In 2016 and 2017, five populations were located, and leaf material, locality information, and demographic data were collected. Microsatellite markers were used to assess genetic diversity and structure among populations, and to compare levels of genetic diversity to closely related congeneric species. Results indicate no evidence of inbreeding in , and there is no genetic structure among the five populations. However, diversity measures trended lower in seedlings compared to mature trees, suggesting allelic diversity may be under threat in the youngest generation of plants. Also, genetic diversity is lower in compared to closely related congeners. The present study provides a baseline estimate of genetic diversity that can be used for comparison in future studies and to other species in the unique limestone karst ecosystems. Considerations for in situ and ex situ conservation approaches are discussed.
东南亚的石灰岩岩溶地区可能拥有高度的特有性，但这些地区高度破碎化，受到的威胁日益增加，而且其生物多样性往往研究不足。马来西亚砂拉越的帕打湾石灰岩地区就是如此，这里是两种重要但未得到充分利用的果树作物——菠萝蜜（Artocarpus heterophyllus）和尖蜜拉（Artocarpus integer）已知最接近的野生近缘种的栖息地。识别和保护作物野生近缘种对于保护作物遗传多样性和育种至关重要。在2016年和2017年，找到了五个Artocarpus integer种群，并收集了叶片材料、产地信息和种群数据。利用微卫星标记评估种群间的遗传多样性和结构，并将遗传多样性水平与近缘同属物种进行比较。结果表明，Artocarpus integer没有近亲繁殖的迹象，五个种群之间也没有遗传结构。然而，与成熟树木相比，幼苗的多样性指标呈下降趋势，这表明等位基因多样性可能在最年轻的植物世代中受到威胁。此外，与近缘同属物种相比，Artocarpus integer的遗传多样性较低。本研究提供了Artocarpus integer遗传多样性的基线估计，可用于未来研究中的比较以及与独特石灰岩岩溶生态系统中的其他物种进行比较。文中还讨论了原地和迁地保护方法的考虑因素。
