DIVERSIDADE E ESTRUTURA GENÉTICA DE Senna reticulata

Senna reticulata (Willd.) H. S. Irwin & Barneby é uma planta arbórea pioneira em áreas abertas de planícies aluviais da Amazônia e frequentemente usada como planta medicinal. Devido à escassez de informações sobre a diversidade da espécie, caracterizou-se a diversidade genética de populações naturais de S. reticulata por meio de marcadores AFLP. Foram coletadas amostras em quatro populações ao longo do trecho do gasoduto Coari-Manaus: Santa Luzia do Baixio, Nossa Senhora de Nazaré, Matrinchã e Esperança II. Foram utilizados quatro primers de AFLP, resultando num total de 330 locos polimórficos variando de 76,97% a 92,42% entre as populações. O dendrograma e a análise bayesiana de agrupamento permitiram a visualização de um grupo formado pelas populações de Nossa Senhora de Nazaré e Esperança II e outro agrupamento formado por Santa Luzia do Baixio. A população de Matrinchã foi caracterizada como a composição de genes dos dois grupos. O fluxo gênico médio estimado entre as populações foi de 4,04 e o teste de Mantel indicou baixa correlação (r = 0,268) entre as matrizes de distância geográfica e distância genética. De acordo com a análise molecular de variância, a maior diferenciação genética está dentro das populações (82,29%), enquanto a variação interpopulacional foi de 17,71%.AbstractGenetic diversity and structure of Senna reticulata. S. reticulata (Willd.) H. S. Irwin & Barneby is a pioneer tree that grows in open areas of the Amazon floodplains and is often used as a medicinal plant species. Due to the lack of information on diversity for this species, this research aimed to characterize the genetic diversity of natural populations of S. reticulata by AFLP markers. The samples were collected in four populations along the natural gas pipeline pathway of Coari-Manaus: Santa Luzia do Baixio, Nossa Senhora de Nazaré, Matrinchã and Esperança II. Four AFLP primers were used, resulting in a total of 330 polymorphic loci ranged from 76.97% to 92.42% among populations. The clustering and Bayesian cluster analysis allowed to discriminate a group composed by the Nossa Senhora de Nazaré and Esperança II populations and another group composed by Santa Luzia do Baixio. Matrinchã population was characterized as a gene composition from both groups. Average gene flow among populations was 4.04 and Mantel test showed low correlation (r = 0.268) between the pairwise of geographic and genetic distance matrices. According to molecular variance analysis, the most genetic differentiation is within populations (82.29%), while the inter population variation was around 17.71%.Keywords: Population differentiation; AFLP marker; genetic variability.AbstractS. reticulata (Willd.) H. S. Irwin & Barneby is a pioneer tree that grows in open areas of the Amazon floodplains and is often used as a medicinal plant species. Due to the lack of information on diversity for this species, this research aimed to characterize the genetic diversity of natural populations of S. reticulata by AFLP markers. The samples were collected in four populations along the natural gas pipeline pathway of Coari-Manaus: Santa Luzia do Baixio, Nossa Senhora de Nazaré, Matrinchã and Esperança II. Four AFLP primers were used, resulting in a total of 330 polymorphic loci ranged from 76.97% to 92.42% among populations. The clustering and Bayesian cluster analysis allowed to discriminate a group composed by the Nossa Senhora de Nazaré and Esperança II populations and another group composed by Santa Luzia do Baixio. Matrinchã population was characterized as a gene composition from both groups. Average gene flow among populations was 4.04 and Mantel test showed low correlation (r = 0.268) between the pairwise of geographic and genetic distance matrices. According to molecular variance analysis, the most genetic differentiation is within populations (82.29%), while the inter population variation was around 17.71%.