Data from: Mating system and effective population size of the overexploited Neotropical tree (Myroxylon peruiferum L.f.) and their impact on seedling production

The reproductive system of a tree species has substantial impact on genetic diversity and structure within and among natural populations. Such information, should be considered when planning tree planting for forest restoration. Here, we describe the mating system and genetic diversity of an overexploited Neotropical tree, Myroxylon peruiferum L.f. (Fabaceae) sampled from a forest remnant (10 seed trees and 200 seeds) and assess whether the effective population size of nursery-grown seedlings (148 seedlings) is sufficient to prevent inbreeding depression in reintroduced populations. Genetic analyses were performed based on eight microsatellite loci. M. peruiferum presented a mixed mating system with evidence of biparental inbreeding ( tm-ts = 0.118). We found low levels of genetic diversity for M. peruiferum species (allelic richness: 1.40 to 4.82; expected heterozygosity: 0.29 to 0.52). Based on Ne(v) within progeny, we suggest a sample size of 47 seed trees to achieve an effective population size of 100. The effective population sizes for the nursey-grown seedlings were much smaller ( Ne = 27.54 to 34.86) than that recommended for short term ( Ne ≥ 100) population conservation. Therefore, to obtain a reasonable genetic representation of native tree species and prevent problems associated with inbreeding depression, seedling production for restoration purposes may require a much larger sampling effort than is currently used, a problem that is further complicated by species with a mixed mating system. This study emphasizes the need to integrate species reproductive biology into seedling production programs and connect conservation genetics with ecological restoration.

树种的生殖系统对自然种群内部及种群间的遗传多样性与遗传结构具有显著影响。在开展森林恢复相关的植树造林规划时，应当将此类信息纳入考量范畴。本文针对一种过度开发的新热带树种——香脂木豆（Myroxylon peruiferum L.f.，豆科（Fabaceae））展开研究：对采自森林残存斑块的该物种样本（含10株母树与200粒种子），分析了其交配系统与遗传多样性；同时评估了苗圃培育的148株实生苗的有效种群大小（effective population size, Ne）是否足以避免再引入种群出现近交衰退。本研究基于8个微卫星位点（microsatellite loci）开展遗传分析。香脂木豆呈现混合交配系统，且存在双亲近交现象（tm-ts = 0.118）。研究发现，香脂木豆的遗传多样性水平较低：等位基因丰富度介于1.40~4.82之间，期望杂合度介于0.29~0.52之间。基于子代的有效种群大小（Ne(v)），我们建议需采集47株母树，以实现100的有效种群大小。苗圃培育实生苗的有效种群大小（Ne = 27.54~34.86）远低于短期种群保护所推荐的阈值（Ne ≥ 100）。因此，若要合理体现本土树种的遗传代表性并规避近交衰退相关问题，用于生态恢复的实生苗培育工作所需的母树采样量，可能远高于当前的常规做法；而对于具有混合交配系统的物种而言，这一问题会更为复杂。本研究强调，需将物种生殖生物学纳入实生苗培育计划，并将保护遗传学与生态恢复工作有机结合。