A novel set of highly polymorphic chloroplast microsatellite and ISSR markers for the biofuel crop Jatropha curcas

Abstract

A novel set of polymorphic ISSR and chloroplast microsatellite markers were identified to mark the genetic relationship among different accessions of Jatropha curcas. A total of 12 polymorphic ISSR primers used, amplified a total of 26 fragments among ten different accessions of J. curcas. The cross-species amplification of microsatellite loci is timesaving as well as a cost-effective approach for developing locus specific markers for new species. Further, in an attempt to reveal a high degree of polymorphism and genetic variation among different accessions of J. curcas chloroplast microsatellite primer pairs developed for Acorus calamus (Acoraceace) were examined for cross-species amplification and validation among them. Out of 18 cpSSRs, six (33.33%) were identified as resulting in good amplifications and polymorphism. The number of amplified alleles per cpSSR primer pair ranged from 2 to 4 with the total number of 18 size variants as whole. The 18 size variants at 6 loci among 10 accessions were combined in 4 different haplotypes. The total chloroplast DNA diversity (HT) and the differentiation (GST) were found as 0.700 and 0.560 respectively. Whereas, Shannon's information index (I), Nei's genetic diversity among different accessions of J. curcas using ISSR and cpSSR markers was estimated at 0.33±0.28; 0.22±0.19 and 0.94±0.35; 0.55±0.18 respectively. The genetic relationship among the accessions was established using UPGMA cluster analysis, which were grouped into two major clusters denoted as cluster-I and cluster-II. The implication of the results in devising the importance of a identified novel set of markers for the genetic relationship and genetic diversity analysis in J. curcas is discussed.