Genetic diversity of long-established populations of Elaeis guineensis jacquin (Arecaceae)

Abstract This study aimed to estimate the genetic diversity of three Elaeis guineensis populations in Rio Grande do Norte state, as well as to verify the decreases in effective population size. The population with the highest polymorphism was MAT (Mata) with+ 57 loci (72%), followed by RIA (Riacho) with 54 loci (68%) and HOR (Horta) with 34 loci (43.03%). The RIA population was shown to be the most genetically diverse, with Nei (h = 0.28) and Shannon (I = 0.41) diversity indices. There was high genetic differentiation among populations (AMOVA, analysis of molecular variance = 42%), which was separated into three distinct genetic groups according to a Bayesian analysis. There was a significant population decrease (P < 0.05) for the HOR population in the IAM (infinite allele model) and SMM (stepwise mutation model), and for the RIA population in the IAM. The data obtained in this study may support ex-situ conservation projects for Elaeis guineensis, contributing to the selection of genotypes and their sustainable use.

摘要 本研究旨在评估北里奥格兰德州（Rio Grande do Norte）境内的三个非洲油棕（Elaeis guineensis）种群的遗传多样性，并验证其有效种群规模的缩减情况。其中多态性最高的种群为MAT（Mata），共包含57个多态位点（占比72%）；其次为RIA（Riacho）种群，含54个多态位点（占比68%）；HOR（Horta）种群的多态位点最少，仅为34个（占比43.03%）。RIA种群的遗传多样性最为丰富，其Nei遗传多样性指数（h=0.28）与香农多样性指数（I=0.41）均处于较高水平。种群间存在较高的遗传分化，经分子方差分析（AMOVA，Analysis of Molecular Variance）检测，遗传分化占比达42%；贝叶斯分析将其划分为三个独立的遗传类群。在无限等位基因模型（IAM，Infinite Allele Model）与逐步突变模型（SMM，Stepwise Mutation Model）下，HOR种群的有效种群规模出现显著缩减（P<0.05）；在IAM模型下，RIA种群亦存在显著的种群规模缩减现象。本研究所得数据可为非洲油棕的迁地保护（ex-situ conservation）项目提供理论支撑，助力优良基因型筛选与资源的可持续利用。