Lacerda D R, Acedo M D, Filho J P, Lovato M B
Departamento de Biologia Geral, Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, CP: 486, Belo Horizonte, MG, 31270-901, Brazil.
Mol Ecol. 2001 May;10(5):1143-52. doi: 10.1046/j.1365-294x.2001.01264.x.
Plathymenia reticulata is a tropical tree native to the Brazilian Cerrado, one of the most important and endangered ecosystems in Brazil. This species presents high-quality wood and potential for recovery of degraded areas. Despite its importance, almost nothing is known about its genetic or ecological features. Random amplified polymorphic DNA (RAPD) markers were used to investigate the genetic diversity and structure of six natural populations of P. reticulata. DNAs from 117 adult individuals were amplified with 10 random primers and Shannon's index and amova were used to evaluate the levels of genetic diversity within and among populations. Through 72 markers, 70.8% of which were polymorphic, it was possible to obtain 117 unique RAPD phenotypes. The levels of genetic variability found in the six populations of P. reticulata were considerable and most of the genetic variation was found between individuals within populations, although pairwise PH(ST) values indicated significant divergence between populations. The among-population component accounted for, respectively, 12.3% and 16% of the genetic variation, according to amova and Shannon's index. These results were compared with other genetic studies on plant species and such a level of differentiation among populations corresponds to that which has usually been observed for outcrossing plants. The importance of maintenance of the P. reticulata populations and implications of the analysis of adult individuals, considering the longevity of this species and the relatively recent Cerrado fragmentation, are discussed.
网脉普拉蒂木是一种热带树木，原产于巴西塞拉多，巴西最重要且濒危的生态系统之一。该物种拥有优质木材，具备恢复退化地区的潜力。尽管其很重要，但人们对其遗传或生态特征几乎一无所知。随机扩增多态性DNA（RAPD）标记被用于研究网脉普拉蒂木六个自然种群的遗传多样性和结构。用10个随机引物对117个成年个体的DNA进行扩增，并使用香农指数和分子方差分析（AMOVA）来评估种群内和种群间的遗传多样性水平。通过72个标记（其中70.8%为多态性标记），获得了117种独特的RAPD表型。在网脉普拉蒂木的六个种群中发现的遗传变异水平相当可观，并且大部分遗传变异存在于种群内的个体之间，尽管成对的PH(ST)值表明种群间存在显著差异。根据分子方差分析和香农指数，种群间成分分别占遗传变异的12.3%和16%。将这些结果与其他关于植物物种的遗传研究进行比较，种群间的这种分化水平与通常在异交植物中观察到的水平相当。考虑到该物种的寿命和塞拉多相对较新的破碎化情况，讨论了维持网脉普拉蒂木种群的重要性以及对成年个体分析的意义。
