Molecular analysis reveals new strategy for data collection in order to explore variability in Jatropha

The objective of this study was to evaluate the genetic diversity between and within populations of Jatrophacurcas using SNP and DArT markers, in order to establish the best selection strategy for this crop. The study of genetic diversity was carried out with 3 segregating families, with 14 individuals each, in an experiment of randomized blocks. For molecular analysis of individuals, 1495 SNP and DArT markers were used. For analyzing the genetic diversity between and within populations of Jatropha, it was used molecular variance analysis (AMOVA), mean heterozygosity, and mean polymorphic information content (PIC). For visually measuring the diversity between and within populations, Tocher and UPGMA clustering methods were used. Through Tocher method, 7 groups were formed. Through AMOVA's results, it was verified that there are differences between families. Estimates were high for variance within (sigma(2)(d)) and between families (sigma(2)(e)). Estimated sigma(2)(d) (280.73) was four times higher than sigma(2)(e) (68.39). Six groups were formed using UPGMA. As the within estimated variance proved to be much greater than the between variance, material collection (accessions) for composing a breeding program should be carried out by collecting fewer families and more seeds per family. As a consequence, variability of Jatropha in breeding programs will be increased, so will the gain with selection, once they are directly correlated. (C) 2015 Elsevier B.V. All rights reserved.