Genetic divergence among Dimorphandra spp. accessions using RAPD markers/Divergencia genetica entre acessos de Dimorphandra spp. usando marcadores RAPD

• Published in: Ciência rural Vol. 41; no. 4; pp. 608 - 613
• Main Authors: Sudre, Claudia Pombo, Rodrigues, Rosana, Goncalves, Leandro Simoes Azeredo, Ma, Pereira, Messias Gonzaga, dos Santos, Marilene Hilma
• Format: Journal Article
• Language: English; Spanish
• Published: Universidade Federal de Santa Maria 01.04.2011
• Subjects: Algorithms; Analysis; Bioflavonoids; caracterização molecular; fava-d'ant; fava-d'anta; Flavones; Flavonoids; germoplasm; germoplasma; molecular characterization; plant genetic resource; recursos genéticos vegetais
• ISSN: 0103-8478; 1678-4596

The genus Dimorphandra has distinguish relevance considering either medicinal or biodiversity aspects because it includes two species that are economically important flavonoids sources for pharmachemical industry (D. mollis Benth. and D. gardneriana Tul.), and species endemic to Brazil, such as D. jorgei Silva and D. wilsonii Rizz., threatened by extinction. In order to evaluate variability among accessions of D. mollis (fava-d'anta), D. gardneriana and D. wilsonii, it was collected fruit from individual plants from three Brazilian states in a total of 57 accessions, which were analyzed with RAPD markers. It was used 20 seeds per progeny; the DNA was extracted from fully-formed young leaves, which were collected in bulk. The data were analyzed using a binary matrix, in which the score one represented presence of a band and zero, absence. The similarity matrix was developed by using the arithmetic complement of the Jaccard index, later grouped based on the Neighbor Joining algorithm. It was found considerable intra and inter specific variability in Dimorphandra spp., which were separated into four groups. Though genetic variability was found, the collecting trips showed that most of these areas are subject to loss of genetic resources of fava-d'anta due to the following factors: continuous anthropic activity, propensity for natural fires, and loss of natural seed dispersers (large fruit-eating mammals). Therefore, protections of these areas and ex situ conservation are essentials for the maintenance of genetic variability of these species. Key words: fava-d'ant, molecular characterization, plant genetic resource, germoplasm. O genero Dimorphandra tem grande relevancia, sobretudo nos aspectos medicinais e de biodiversidade, por incluir duas especies que sao importantes economicamente como fontes de flavonoides para industria farmacoquimica (D. mollis Benth. e D. gardneriana Tull.), e especies endemicas do Brasil, como a D. jorgei Silva e D. wilsonii Rizz., sendo esta ameacada de extincao. Objetivando avaliar a variabilidade entre acessos de D. mollis, D. gardneriana e D. wilsonii, foram realizadas coletas de frutos separados por planta em tres estados brasileiros em um total de 57 acessos que foram analisados por meio da tecnica RAPD. Utilizaram-se vinte sementes por progenie e o DNA, extraido de folhas definitivas, jovens, e coletadas em bulk. Os dados foram analisados utilizando-se uma matriz de dados binarios. Para formacao da matriz de dissimilaridade, foi utilizado o complemento aritmetico do Indice de Jaccard e posteriormente o agrupamento pelo algoritmo de Neighbor Joining. O estudo revelou que existe variabilidade entre e dentro das especies de Dimorphandra spp., o qual formou quatro grupos. Apesar da variabilidade genetica constatada, as expedicoes de coleta demonstraram que a maioria das areas amostradas esta sujeita a perdas de recursos geneticos de fava-d'anta devido aos seguintes fatores: ocorrencia de acao antropica continua; propensao a incendios naturais; e diminuicao dos dispersores naturais de sementes (grandes mamiferos frugiveros). Assim, a protecao destas areas e a conservacao ex situ, sao primordiais para manutencao da variabilidade genetica dessas especies. Palavras-chave: fava-d'anta, caracterizacao molecular, recursos geneticos vegetais, germoplasma.