巴西大西洋森林濒危树种黑黄檀（蝶形花亚科）残存种群的遗传变异

Genetic variation in remnant populations of Dalbergia nigra (Papilionoideae), an endangered tree from the Brazilian Atlantic Forest.

作者信息

Ribeiro Renata Acácio, Simões Ramos Ana Carolina, De Lemos Filho José Pires, Lovato Maria Bernadete

机构信息

Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.

出版信息

Ann Bot. 2005 Jun;95(7):1171-7. doi: 10.1093/aob/mci128. Epub 2005 Mar 24.

DOI:10.1093/aob/mci128

PMID:15790585

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4246900/

Abstract

BACKGROUND AND AIMS

Dalbergia nigra, known as Brazilian rosewood, is an endangered tree species restricted to the Brazilian Atlantic Forest and has been intensively logged for five centuries due to its high-quality wood. The objective of the present study was to assess the genetic variation and structure in adults and saplings of the species from a large reserve of the Atlantic Forest, the Rio Doce State Park, and from two small surrounding fragments, one better preserved and another with a high degree of anthropogenic disturbance.

METHODS

Analyses of genetic variation and structure were conducted by studying allozyme markers. Seven putative enzymatic loci were resolved, five of them being polymorphic.

KEY RESULTS

The mean numbers of alleles per locus (A) were 1.93 and 1.73, while the percentages of polymorphic loci (P) were 93 and 73 % for adults and saplings, respectively. Saplings from the fragment with high anthropogenic disturbance exhibited the lowest values of A and P. The fragment that constitutes a conservation area exhibited genetic variation similar to the population from the large reserve. The observed (H(o)) and expected (H(e)) heterozygosities were not significantly different among the three populations. Only sapling populations showed F(ST) values (divergence among populations) significantly different from zero over all studied loci. The fragment with high anthropogenic disturbance exhibited considerable genetic divergence in relation to the above-cited populations.

CONCLUSIONS

The evaluated populations displayed mean levels of genetic variation intermediate to those expected for narrow and widespread species. The results suggest that fragments with similar area and geographical distance from a large protected reserve can exhibit different levels of genetic variation, depending on the degree of anthropogenic disturbance. The considerable genetic variation in the protected fragment points to the importance of adequate conservation of small fragments for the preservation of genetic variation in D. nigra.

摘要

背景与目的

黑黄檀，即巴西黄檀，是一种濒危树种，仅存于巴西大西洋森林。因其优质木材，在五个世纪里一直遭受大量砍伐。本研究的目的是评估该物种在大西洋森林的一个大型保护区——多西河州立公园以及周边两个小碎片区域（一个保存较好，另一个人为干扰程度高）的成年植株和幼树中的遗传变异与结构。

方法

通过研究等位酶标记进行遗传变异与结构分析。解析出七个假定的酶位点，其中五个为多态性位点。

关键结果

每个位点的平均等位基因数（A）在成年植株和幼树中分别为1.93和1.73，而多态性位点的百分比（P）在成年植株和幼树中分别为93%和73%。人为干扰程度高的碎片区域中的幼树A和P值最低。构成保护区的碎片区域所表现出的遗传变异与大型保护区中的种群相似。在这三个种群中，观察到的杂合度（H(o)）和预期杂合度（H(e)）没有显著差异。仅幼树种群在所有研究位点上显示出F(ST)值（种群间差异）显著不同于零。人为干扰程度高的碎片区域与上述种群相比表现出相当大的遗传差异。