Genetic divergence analysis of Jatropha (Jatropha curcus L.) germplasm based on nuclear ribosomal DNA ITS sequence

The genetic divergency of Jatropha curcas L. germplasm, collected from different countries or districts, was investigated by using nuclear ribosomal DNA ITS sequence (nrDNA ITS) to provide useful information for selection and utilization of superior provenance of J. curcas. The sequencing results showed that the size variation obtained among sequenced nrDNA ITS regions was narrow and ranged from 648 to 649 bp and G+C content was from 64.10% to 64.71%. By Kimura-2 parameter analysis, low genetic distance of germplasm was found from 0.000 to 0.069 and the overall mean genetic distance was 0.010. The phylogram showed that no clade was found. And the difference coefficient in UPGMA tree was less than 0.005. The result indicated that the germplasm of J. curcas has narrow genetic base and low genetic variation.