Diversidade genética de genótipos de pinhão-manso por meio de RAPD e ISSR

Abstract

Physic nut (Jatropha curcas L.) is an oleaginous plant that possesses agricultural characteristics such as high productivity and high oil content in seeds, becoming an excellent candidate for biofuell production. Its domestication began just in the last 30 years, and little is known about its genetic diversity. This study aimed to analyze the genetic diversity among 46 genotypes of physic nut by means of RAPD and ISSR markers. The evaluated genotypes belongs to EPAMIG / URNM's collection, composed by accesses collected in the Norte de Minas Gerais, Vale do Jequitinhonha, besides introductions from China and Cabo Verde. The DNA was extracted through method proposed by Basha and Sujatha (2007). For the amplification reactions were used 33 RAPD primers and 13 ISSR ones. The genetic distances were calculated based on DICE similarity coefficient, and according to them was drawn up a dendrogram from the cluster analysis by Unweighted Pair Groups Method with Arithmetic Mean (UPGMA) of the whole data matrix. For the data analysis it was used the statistical program Genes. It was possible to observe the formation of only two clusters, from which one had only tree individuals, and one 95,6% of the genotypes analyzed. The genetic distance ranged from 1,26 to 76,15%, with average genetic distance of 20,90%. The most divergent genotypes were 86, 71 and 83. The low genetic diversity found indicates the need to initiate investigations in order to broaden the genetic base and to increase the variability of this specie. The genotypes 86, 71 and 83, for possess high value in genetic distance, can be used as parents in a breeding program.