Genetic analysis of twenty two selected genotypes of Jatropha curcas L. (physic nut) from Africa, Asia and America, using SSR and AFLP markers

Abstract

Twenty two genotypes of J. curcas L. from Africa (Senegal, Burkina Faso, Mali, Congo and Madagascar Island), Asia (Cambodia, China and India) and America (Ecuador, Dominican Republic and Brazil) selected for their vigor and their productivity were analyzed with ten SSR primer pairs and six AFLP primer combinations. The two marker approaches showed their ability to effectively reveal polymorphism among the selected genotypes: 94.02 and 56% of polymorphism for AFLPs and SSRs respectively. Among the three groups of selected genotypes, the Asian group was the least diverse while the genetic diversities found in African and American groups were slightly comparable. The Nei’s genetic diversity (He) of all twenty-two selected genotypes was 0.2029 based on combined SSR+AFLP data. The Gst value and the AMOVA analysis indicated that more than 80% of the genetic diversity resided within the groups. The analysis of the genetic relationships between the genotypes using the Nei’s standard dissimilarity matrix gave dissimilarity coefficients ranging from 0.14397 to 0.73943 with an average of 0.3540. The most distant genotypes were found between a genotype from Africa (Congo) and one from America (Ecuador). The clustering of genotypes obtained with the neighbor-joining dendrogram and the PCoA analysis revealed the existence of a certain level of diversity that can be used by breeders.   Key words: Biodiesel, genetic diversity, jatropha, molecular markers, AFLP, SSR, plant breeding.