Cedrela fissilis Vell. has a wide distribution in South and Central America, and in neotropical forests the species occurs at a low density. Its wood is one of the most valued around the world, and the species is currently at risk of extinction due to both habitat fragmentation and illegal logging. Considering the need for conservation strategies, this study aims to investigate the genetic structure, diversity, and inbreeding in C. fissilis populations from the Atlantic Forest. To do this, nine microsatellite loci were used to genotype 289 individuals from eight undisturbed and disturbed fragments. Two of the eight populations harbor most of the genetic diversity: one includes most of the diversity present in all populations and the other is isolated but with high levels of diversity. Genetic diversity was higher within than among populations, with observed and expected heterozygosities ranging from 0.48 to 0.63 and from 0.55 to 0.70, respectively. We detected a significant fixation index, ranging from 0.08 to 0.24 and 32% of the observed alleles were exclusive of some population. The populations showed moderate genetic structure (F_ST = 0.10) and the Bayesian analysis grouped the studied individuals into three distinct genetic clusters that seem to be related to the presence of geographical barriers. The overall analyses of the results allow us to conclude that protecting only isolated fragments, either large or small, may be ineffective for conserving the C. fissilis gene pool in the studied region. This observation suggests that an appropriate strategy to conserve the gene pool of the species is to maintain both the Atlantic Forest green belt in the eastern portion of the Central and South region of this biome, where the forest is not highly fragmented, as well as the remaining forest areas to the west of the Paraná River.

中文翻译：

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栖息地流失对小叶绒毛虫遗传多样性和种群结构的影响。

Cedrela fissilis Vell。在南美和中美洲分布广泛，在新热带森林中，该物种的密度很低。它的木材是世界上最有价值的木材之一，由于栖息地破碎和非法砍伐，该树种目前面临灭绝的风险。考虑到保护策略的必要性，本研究旨在调查纤毛衣藻的遗传结构，多样性和近交。大西洋森林的种群。为此，使用了9个微卫星基因座，对来自8个不受干扰和受干扰的片段的289个人进行了基因分型。八个种群中有两个具有大部分遗传多样性：一个包括所有种群中存在的大多数多样性，另一个是孤立的，但具有高度的多样性。内部的遗传多样性高于种群之间的遗传多样性，观察到和预期的杂合度分别为0.48至0.63和0.55至0.70。我们检测到显着的固定指数，范围为0.08至0.24，观察到的等位基因中有32％不包括某些人群。种群显示出中等的遗传结构（F _ST = 0.10），而贝叶斯分析则将研究对象分为三个不同的遗传簇，这些簇似乎与地理障碍有关。对结果的整体分析使我们得出结论，仅保护分离的片段（无论大小）对于在研究区域保存菲氏梭菌基因库可能无效。该观察结果表明，保护该物种基因库的适当策略是在该生物群落中部和南部区域的东部保持大西洋森林绿带，在该区域中森林不是高度分散的，并且巴拉那河以西的其余林区。