AFLP analysis of Genetic Diversity Among Different Jatropha curcas L. Genotypes from Africa and Ecuador

Six populations amounting to a total number of seventy genotypes of Jatropha curcas L. originating from Africa (Senegal, Mali, Burkina Faso and Madagascar) and Ecuador were investigated for genetic diversity using two AFLP primer combinations. The results revealed a high genetic diversity in the populations studied. The population with greatest genetic diversity was Madagascar (He = 0.2638 and I = 0.4066) and the least diverse was Senegal-Tamba (He = 0.1962 and I = 0.3079). AMOVA (analysis of molecular variance) detected the highest proportion of variation within populations (81% of the total molecular variation). This may be attributed to the high level of allogamy observed in this species. The Nei's standard unbiased genetic distance (D) between the populations ranged from 0.010 (Senegal-Tamba and Burkina Faso) to 0.131 (Mali and Ecuador); the average was 0.063. Analysis of the genetic relationships among the 6 populations using both neighbor-joining cluster analysis and principal component analysis (PCoA) showed five clusters with globally, groupings of i) most of Burkina Faso and Senegal-Tamba genotypes, ii) most of Mali and Senegal-Diobass genotypes , iii) most of Madagascar and Ecuador genotypes, and iv) some mixings of genotypes with different origins. Considering the distance existing between the different origins there are prospects to develop F1 hybrids. The greatest heterosis might be expected from crossing involving genotypes of cluster I and cluster V which group the more distant genotypes. Such crossing schemes might produce greater success in the production of genetic variability and might maximize the exploitation of heterosis and segregation