Santos A S, Leal J B, Corrêa R X, Gramacho K P, Gaiotto F A
Departamento de Ciências Biológicas, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Universidade Estadual de Feira de Santana - UEFS, Feira de Santana, Brazil.
Laboratório de Ecologia Aplicada À Conservação, Universidade Estadual de Santa Cruz, Ilhéus, Brazil.
BMC Ecol Evol. 2025 Sep 1;25(1):89. doi: 10.1186/s12862-025-02418-3.
Deforestation in the Atlantic Forest has reached critical levels, threatening multiple levels of biodiversity. In these deforested landscapes, conservation strategies could benefit from preserving agroforestry systems known as Cabruca, a traditional method of cultivating cocoa under a canopy of native trees. In this context, Cariniana legalis (Jequitibá-rosa), an endemic tree species of the Atlantic Forest listed as endangered, was selected to evaluate the role of cocoa agroforests (Cabrucas) and forest remnants in the genetic conservation of this species. The study assessed the genetic diversity, inbreeding levels, and genetic structure of five populations of C. legalis located in forest remnants protected by law and in Cabrucas in southern Bahia, Brazil. Using 11 microsatellite loci, 294 individuals were genotyped for adult and juvenile ontogenetic stages. Despite forest fragmentation, some populations, especially those located in Cabrucas, retained high levels of genetic diversity in both stages. In contrast, a protected area exhibited lower genetic diversity and elevated inbreeding levels (f > 0.43) in both adults and juveniles. Analyses of genetic differentiation (F) and migration rate (Nm) indicated reduced historical gene flow in certain populations, while network analysis and Discriminant Analysis of Principal Components (DAPC) identified Cabrucas as central genetic hubs promoting connectivity across the landscape in both ontogenetic stages. Our results highlight the conservation value of cocoa agroforests for maintaining the genetic diversity and connectivity of this endangered tree species. We therefore recommend the inclusion of Cabrucas in integrated genetic conservation strategies for C. legalis in anthropogenically modified Atlantic Forest landscapes.
大西洋森林的森林砍伐已达到危急程度，威胁到多个层面的生物多样性。在这些森林砍伐后的景观中，保护策略可受益于保护一种名为卡布鲁卡（Cabruca）的农林业系统，这是一种在原生树冠层下种植可可的传统方法。在此背景下，选择了列入濒危物种名单的大西洋森林特有树种卡氏铁木（Cariniana legalis，又称红木），以评估可可农林业（卡布鲁卡）和森林残余物在该物种遗传保护中的作用。该研究评估了位于巴西巴伊亚州南部依法保护的森林残余物以及卡布鲁卡中的五个卡氏铁木种群的遗传多样性、近亲繁殖水平和遗传结构。利用11个微卫星位点，对294个个体在成年和幼年个体发育阶段进行了基因分型。尽管森林破碎化，但一些种群，特别是位于卡布鲁卡中的种群，在两个阶段都保持了较高水平的遗传多样性。相比之下，一个保护区在成年和幼年个体中均表现出较低的遗传多样性和较高的近亲繁殖水平（f > 0.43）。遗传分化（F）和迁移率（Nm）分析表明，某些种群的历史基因流减少，而网络分析和主成分判别分析（DAPC）将卡布鲁卡确定为促进两个个体发育阶段整个景观连通性的核心遗传枢纽。我们的研究结果突出了可可农林业对于维持这种濒危树种的遗传多样性和连通性的保护价值。因此，我们建议将卡布鲁卡纳入人为改造的大西洋森林景观中卡氏铁木的综合遗传保护策略。
