Genetic data on threatened plant populations can facilitate the development of adequate conservation strategies to reduce extinction risk. Such data are particularly important for species affected by habitat fragmentation such asMagnolia cubensissubsp.acunae, a Critically Endangered magnolia subspecies endemic to Cuba. Using genetic data from 67 individuals, we aimed to evaluate the effect of habitat fragmentation on two subpopulations in the Guamuhaya mountain range, in Topes de Collantes Protected Natural Landscape and Lomas de Banao Ecological Reserve. We characterize the structure and genetic diversity of these subpopulations, with the objective of managing their conservation more effectively. We used Landsat satellite images to determine land-cover types at the two locations and calculated indices of habitat fragmentation. For genetic analyses, we extracted DNA from the leaf tissue of individuals from the two subpopulations and used 11 microsatellite markers to genotype them. We calculated heterozygosity, allelic richness and theF-statistics, to evaluate genetic variability. The montane rainforest in Topes de Collantes was most affected by habitat fragmentation, with smaller patches of more irregular shapes, compared to submontane forest at this location and both montane and submontane forests in Lomas de Banao. Genetic diversity was higher in Topes de Collantes, but we found no genetic differentiation between subpopulations. Our findings suggest the two subpopulations can be considered a single evolutionary unit and conservation entity. We propose to use individuals from both subpopulations for reinforcement to increase the overall genetic diversity of the subspecies.

中文翻译：

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Magnolia cubesissubsp.acunae（Magnoliaceae）种群结构和遗传多样性：栖息地破碎化的影响和对保护的意义

有关受威胁植物种群的遗传数据可以促进制定适当的保护战略以降低灭绝风险。这些数据对于受栖息地破碎化影响的物种尤其重要，例如木兰亚种针尖，古巴特有的极度濒危的木兰亚种。我们使用来自 67 个人的遗传数据，旨在评估栖息地破碎化对 Guamuhaya 山脉 Topes de Collantes 受保护的自然景观和 Lomas de Banao 生态保护区的两个亚群的影响。我们描述了这些亚群的结构和遗传多样性，目的是更有效地管理它们的保护。我们使用 Landsat 卫星图像来确定两个地点的土地覆盖类型并计算栖息地破碎指数。对于遗传分析，我们从两个亚群个体的叶组织中提取 DNA，并使用 11 个微卫星标记对它们进行基因分型。我们计算了杂合性、等位基因丰富度和F-统计，以评估遗传变异性。Topes de Collantes 的山地雨林受栖息地破碎化的影响最大，与该位置的亚山地森林以及 Lomas de Banao 的山地和亚山地森林相比，更小的斑块更不规则的形状。Topes de Collantes 的遗传多样性较高，但我们发现亚群之间没有遗传差异。我们的研究结果表明，这两个亚群可以被视为一个单一的进化单位和保护实体。我们建议使用来自两个亚群的个体进行强化，以增加亚种的整体遗传多样性。