Molecular phylogenetic analysis of key Jatropha species inferred from nrDNA ITS and chloroplast (trnL-F and rbcL) sequences

Abstract

The genus Jatropha (Euphorbiaceae) contains species that are of significant economic and ornamental value. However, Jatropha breeding material is rather limited due to incomplete information regarding phylogenetic relationships among germplasm resources. Phylogenetic analyses were performed based on the internal transcribed spacer of nuclear ribosomal DNA (nrDNA ITS), two chloroplast regions (trnL-F and rbcL), and the combined (ITS?trnL-F?rbcL) dataset among twenty-five specimens representing six key Jatropha species. Phylogenetic relationships of Jatropha were well resolved between subgenus Curcas and subgenus Jatropha, and demonstrated the intermediate position of section Polymorphae among sections of both subgenera. Jatropha curcas and J. integerrima demonstrated a close phylogenetic relationship. The molecular data agreed with the morphological classification that recognized J. multifida and J. podagrica in sec. Peltatae. The distinct intraspecific divergence that occurred in J. curcas could be attributed to restricted gene flow caused by geographical isolation and different ecological conditions. Phylograms produced with trnL-F and rbcL sequence data suggested slow rates of sequence divergence among Jatropha spp., while the ITS gene tree had good resolution suggesting high genetic variation of ITS among Jatropha species.

Molecular confirmation of two medicinal species of Jatropha L. (Euphorbiaceae) used by the Agusan Manobo in the Philippines

“…A BLASTn search was performed to check for species identity using the BLASTn algorithm available in the GenBank (www.ncbi.nim.nih.gov), as shown in Table 1. Jatropha species [4], including from the study of Guo et al [11] of key Jatropha species, were included in the analysis. A total of 30 accessions of Jatropha species and an outgroup (Croton draco Schltdl.)…”

“…As for the subgenus Curcas, all J. curcas specimens were grouped in Clade V, wherein the majority, including the collected sample, was branched from one same lineage. The other three J. curcas (labeled as 1, 5, and 6) separated from the majority of J. curcas, which suggests that these were the probable cause of varied geographical and environmental conditions [11]. As opposed to the obtained accessions from Myanmar, other parts of China, India, Mali, Burkina Faso, and Philippine tropics, these three divergent J. curcas (labeled 1,5 and 6) share their origins from the arid-upland climate of Southwestern China [20].…”

“…In verifying the species identity of medicinal plants with similar local names or uncertain species identity, the use of molecular sequences has become a powerful tool [11]. The two "tubatuba" voucher specimens were verified as J. curcas for "tubatuba puti" and J. gossypiifolia for "tubatuba tapol" based on the ITS marker.…”