Molecular characterization and genetic diversity of Jatropha curcas L. in Costa Rica

Abstract

We estimated the genetic diversity of 50 Jatropha curcas samples from the Costa Rican germplasm bank using 18 EST-SSR, one G-SSR and nrDNA-ITS markers. We also evaluated the phylogenetic relationships among samples using nuclear ribosomal ITS markers. Nontoxicity was evaluated using G-SSRs and SCARs markers. A Neighbor-Joining (NJ) tree and a Maximum Likelihood (ML) tree were constructed using SSR markers and ITS sequences, respectively. Heterozygosity was moderate (He = 0.346), but considerable compared to worldwide values for J. curcas. The PIC (PIC = 0.274) and inbreeding coefficient (f = -0.102) were both low. Clustering was not related to the geographical origin of accessions.International accessions clustered independently of collection sites, suggesting a lack of genetic structure, probably due to the wide distribution of this crop and ample gene flow. 24 We estimated the genetic diversity of 50 Jatropha curcas samples from the Costa Rican 25 germplasm bank using 18 EST-SSR, one G-SSR and nrDNA-ITS markers. We also evaluated the 26 phylogenetic relationships among samples using nuclear ribosomal ITS markers. Non-toxicity was 27 evaluated using G-SSRs and SCARs markers. A Neighbor-Joining (NJ) tree and a Maximum 28 Likelihood (ML) tree were constructed using SSR markers and ITS sequences, respectively.