Jara-Arancio Paola, da Silva Carvalho Carolina, Carmona-Ortiz Martín R, Bustamante Ramiro O, Schmidt Villela Priscilla M, da Silva Andrade Sónia C, Peña-Gómez Francisco T, González Luís A, Fleury Marina
Instituto de Ecología y Biodiversidad (IEB), Victoria 631, Barrio Universitario, Concepción 4030000, Chile.
Centro Internacional Cabo de Hornos (CHIC), Universidad de Magallanes, Teniente Muñoz 166, Puerto Williams 6350000, Chile.
Plants (Basel). 2022 Jul 28;11(15):1959. doi: 10.3390/plants11151959.
(Molina) Baill., also named Chilean palm, is an endemic species found in the coastal area of Mediterranean sclerophyllous forest in Chile. It has a highly restricted and fragmented distribution along the coast, being under intense exploitation and anthropogenic impact. Based on 1038 SNP markers, we evaluated the genetic diversity and population structure among six natural groups encompassing 96% of the species distribution. We observed low levels of genetic diversity, a deficit of heterozygotes (mean = 0.024; = 0.014), and high levels of inbreeding (mean = 0.424). The fixation index () and Nei's genetic distance pairwise comparisons indicated low to moderate structuring among populations. There was no evidence of isolation by distance ( = -0.214, = 0.799). In the cluster analysis, we observed a closer relationship among Culimo, Cocalán, and Candelaria populations. Migration rates among populations were low, except for some populations with moderate values. The K value that best represented the spatial distribution of genetic diversity was ∆K = 3. Habitat fragmentation, deterioration of the sclerophyllous forest, lack of long-distance dispersers, and a natural regeneration deficit may have driven inbreeding and low levels of genetic diversity in the palm groves of . Although extant populations are not at imminent risk of extinction, the rate of inbreeding could increase and migration could decrease if the effects of climate change and human impact become more acute.
（莫利纳）贝利榈，也被称为智利棕榈，是一种分布于智利地中海硬叶林沿海地区的特有物种。它在沿海地区的分布极为有限且碎片化，正遭受着高强度的开发利用和人为影响。基于1038个单核苷酸多态性（SNP）标记，我们评估了涵盖该物种96%分布范围的六个自然群体的遗传多样性和种群结构。我们观察到遗传多样性水平较低、杂合子缺失（均值 = 0.024；标准差 = 0.014）以及近亲繁殖水平较高（均值 = 0.424）。固定指数（F）和内氏遗传距离的成对比较表明种群间存在低到中等程度的结构分化。没有证据表明存在距离隔离（r = -0.214，P = 0.799）。在聚类分析中，我们观察到库里莫、科卡兰和坎德拉里亚种群之间关系更为密切。除了一些具有中等迁移率值的种群外，种群间的迁移率较低。最能代表遗传多样性空间分布的K值为∆K = 3。栖息地破碎化、硬叶林退化、缺乏远距离传播者以及自然更新不足可能导致了该棕榈林的近亲繁殖和低遗传多样性水平。尽管现存种群并非面临迫在眉睫的灭绝风险，但如果气候变化和人类影响的效应变得更加严重，近亲繁殖率可能会增加，而迁移率可能会降低。
