Molecular characterization of Jatropha genetic resources through inter-simple sequence repeat (ISSR) markers

The genetic diversity among eight Jatropha species and three Jatropha curcas accessions were analyzed using ISSR-PCR. Nine ISSR primers generated reproducible amplification banding pattern of 61 polymorphic bands out of 64 scored accounting for 98.14% polymorphism across the species. The ISSR primers viz., I1, I2, I3, I4, I5, I6, I7 and I10 generated 100% polymorphic patterns. Jaccard's coefficient of similarity varied from 0.346 to 0.807, indicative of high level of genetic variation among the genotypes studied. The UPGMA cluster analysis indicated three distinct clusters, one comprising all accessions of J. curcas L (TNMJ1, TNMJ 22 and TNMJ 23), while second included four species viz., J. tanjorensis J. L. Ellis et Saroja., J. gossypifolia L., J. podagrica Hook and J. maheshwarii Subrum and M.P. Nayer and the third cluster included another four species viz., J. villosa Wight J. multifida L., J. integerrima Jacq and J. glandulifera Roxb. The overall grouping pattern of clustering corresponds well with principal component analysis (PCA) confirming patterns of genetic diversity observed among the species. So far, there are no reports on the molecular diversity of the Jatropha species through ISSR marker. This study provides valid guidelines for collection, conservation and characterization of Jatropha genetic resources and also for further breeding programme towards biodiesel production.