Phylogenetic Relationships And Molecular Identification Of Garcinia Species Revealed By ITS+rbcL Sequence Data

Garcinia is a tropical genus in Clusiaceae, distributed mostly in south-east Asia, southern Africa and Polynesia. It is known for its traditional uses such as edible edible and medicinal purposes. In China, the genus Garcinia is used widely. Ethnic minorities in southern China such as Dai and Li use G. xanthochymus, G. oblongifolia and G. xipshuanbannaensis as fruits and food seasoning for a long time. Lisu people use G. multiflora to treat enteritis and gastric ulcer, while She people use G. mangotana to treat cough.Due to unclear phylogenetic relationship and similar morphology, the identification of Garcinia species is difficult. We used DNA barcoding to reveal their relationship and to achieve their molecular identification. This research will promote the development and protection of Garcinia germplasm resources. It will also protect the traditional knowledge of Garcinia species.We collected seventy samples belonged to sixteen species of Garcinia, chose ITS and rbcL sequences as DNA barcoding, used K2P genetic distance, "DNA barcoding" assess, maximum likelihood and neighbor-joining method to explore the genetic relationship and phylogenetic of Garcinia species.Through our research, we found that ITS+rbcL sequence can distinguish all the samples clearly, so ITS+rbcL is the ideal DNA barcoding in identification of Garcinia species. From the phylogenetic tree, we could get the result of phylogenetic relationship among Garcinia speices. The species distributed in different areas were separated into different clades, showing that different habitats may cause different evolutionary processes. G. mangotana and G. multiflora collected from different areas can be also clearly separated, it indicated that these two species have high genetic diversity in China, and ITS+rbcL has good identification ability for our samples.Comparing phylogenetic relationship based on DNA barcoding data with classical classification system based on morphological data, there are similarities and differences between them. We proposed that DNA barcoding technology can provide useful information for classical classification, and it can make the plant identification become more scientific and accurate.This study got several new DNA barcoding sequences which were not contained in NCBI, making the molecular identification of these species become possible. We hope that future research can involve more Garcinia species, constructing the DNA barcode database of Garcinia, and improving the molecular identification efficiency.