Genetic diversity and population structure of endangered rosewood from the Peruvian Amazon using ISSR markers

ABSTRACT Rosewood, Aniba rosaeodora is an endangered species in Amazon forests and its natural stands have been heavily depleted due to over-exploitation for the cosmetic industry. This study aimed to investigate the genetic diversity and population structure of 90 rosewood accessions from eight localities in the Peruvian Amazon through 11 Inter Simple Sequence Repeats (ISSR) primers. The ISSR primers produced a sum of 378 bands, of which 375 (99.2%) were polymorphic, with an average polymorphism information content (PIC) value of 0.774. The mean effective number of alleles (Ne), Shannon informative index (I), gene diversity (He) and total gene diversity (Ht) were 1.485, 0.294, 0.453 and 0.252, respectively. Analysis of molecular variance (AMOVA) showed the presence of maximum variability within populations (88%). The Structure algorithm, neighbor joining and principal coordinate analysis (PCoA) grouped the 90 rosewood accessions into three main populations (A, B and C). Diversity indices at the inter-population level revealed a greater genetic diversity in population A, due to higher gene flow. The neighbor-joining analysis grouped populations A and B, while population C was found to be divergent at the inter population level. We concluded that population A reflects higher genetic diversity and should be prioritized for future management and conservation plans.

摘要：玫瑰木（Aniba rosaeodora）是亚马逊森林中的濒危物种，因化妆品行业的过度开发利用，其天然林分已遭到严重破坏。本研究采用11对简单序列重复区间（Inter Simple Sequence Repeats，ISSR）引物，对秘鲁亚马逊地区8个样地的90份玫瑰木种质资源的遗传多样性与群体结构展开探究。结果显示，ISSR引物共扩增得到378条条带，其中375条（99.2%）具有多态性，平均多态信息含量（Polymorphism Information Content, PIC）值为0.774。有效等位基因数（effective number of alleles, Ne）、香农信息指数（Shannon Informative Index, I）、基因多样性（gene diversity, He）及总基因多样性（total gene diversity, Ht）的均值分别为1.485、0.294、0.453与0.252。分子方差分析（Analysis of Molecular Variance, AMOVA）结果表明，群体内变异占总变异的比例最高（88%）。通过Structure算法、邻接法与主坐标分析（Principal Coordinate Analysis, PCoA），可将90份玫瑰木种质资源划分为A、B、C三个主要类群。群体间多样性指数分析显示，由于较高的基因流水平，类群A的遗传多样性更为丰富。邻接聚类分析将类群A与类群B聚为一类，而类群C在群体水平上呈现出显著分化。本研究认为，类群A具备更高的遗传多样性，应在未来的管理与保护规划中获得优先保护。