Souza L C, Júnior A L Silva, Souza M C, Kunz S H, Miranda F D
Programa de Pós-Graduação em Genética e Melhoramento, Laboratório de Bioquímica e Biologia Molecular, Centro de Ciências Agrárias e Engenharias, Universidade Federal do Espírito Santo, Alegre, ES, Brasil
Programa de Pós-Graduação em Genética e Melhoramento, Laboratório de Bioquímica e Biologia Molecular, Centro de Ciências Agrárias e Engenharias, Universidade Federal do Espírito Santo, Alegre, ES, Brasil.
Genet Mol Res. 2017 Sep 21;16(3):gmr-16-03-gmr.16039775. doi: 10.4238/gmr16039775.
Studies of genetic diversity in natural populations are important for the definition of conservation strategies, especially in populations reduced by processes of fragmentation and continuous forest extraction. Molecular markers stand out as interesting tools for these studies. The objective of this research was to characterize the diversity and genetic structure of Plathymenia reticulata (Fabaceae), occurring in two fragments of the Montana Semideciduous Forest in the southern of Espírito Santo State, Brazil, using inter-simple sequence repeat (ISSR) molecular markers. DNA samples from 149 individuals were analyzed using 10 ISSR primers, generating 156 fragments, of which 101 were polymorphic (64.74%). The individuals sampled were classified into three units: adult trees (A), a mixture of progenies (B), and young regenerating individuals (C). The number of loci used (N = 101) was greater than that established as optimal number (N = 88), indicating precision in analyses. The genetic diversity index of Nei (H' = 0.407) and the Shannon index (I = 0.594) were found to have high genetic diversity. Besides, through the diversity parameters evaluated, it was possible to confirm that in the areas of natural regeneration and progeny mix there is genetic diversity equivalent to that found in adults. The analysis of molecular variance indicated that most of the genetic variation is found within the groups (96.53%). Genetic differentiation among adult trees was low (Φ = 0.03) indicating that high gene flow rates (N = 12.70) are counteracting the effects of genetic drift. The data obtained allowed to evaluate the potential of adult trees as matrices for seed collection and to obtain seedlings with confirmed genetic variability.
对自然种群的遗传多样性进行研究对于制定保护策略至关重要，特别是对于因碎片化和持续森林采伐而数量减少的种群。分子标记是这些研究中很有趣的工具。本研究的目的是利用简单序列重复区间（ISSR）分子标记，对巴西圣埃斯皮里图州南部蒙大拿半落叶森林两个片段中的网脉豆（豆科）的多样性和遗传结构进行表征。使用10个ISSR引物对149个个体的DNA样本进行分析，共产生156个片段，其中101个为多态性片段（64.74%）。所采样的个体分为三个单元：成年树（A）、子代混合群体（B）和幼龄再生个体（C）。所用位点数量（N = 101）大于确定的最佳数量（N = 88），表明分析具有精确性。发现内氏遗传多样性指数（H' = 0.407）和香农指数（I = 0.594）显示出高遗传多样性。此外，通过评估的多样性参数，可以确认在自然更新区域和子代混合群体中存在与成年树相当的遗传多样性。分子方差分析表明，大部分遗传变异存在于群体内部（96.53%）。成年树之间的遗传分化较低（Φ = 0.03），表明高基因流率（N = 12.70）正在抵消遗传漂变的影响。所获得的数据有助于评估成年树作为种子采集母体的潜力，并获得具有确定遗传变异性的幼苗。
