Large-scale biodiversity inventories are based on accurate species identification. Unfortunately, errors are common for tropical trees, usually due to the lack of reproductive characters. DNA barcoding could quickly and effectively help to correct morphological identification errors. However, there are no DNA barcode studies from tropical areas of China, which represents one of the biodiversity hotspots around the world.
Prof. LI Jie and his team of Xishuangbanna Tropical Botanical Garden (XTBG) conducted field work from 2008 to 2012 and used a plot-based sampling strategy to establish a local DNA barcode database of tropical trees occurring two different vegetation types and evaluate the performance of DNA barcodes in the Xishuangbanna Nature Reserve. They used rbcL and matK as standard barcodes, and trnH–psbA and ITS as supplementary barcodes. They analyzed sequence recovery and species discrimination of the four barcodes rbcL, matK, trnH–psbA and ITS singly and in combination.
The researchers wanted to assess errors of morphological identification in ecological surveys based on core barcodes (rbcL and matK), and compare sequence recovery of the four selected markers between their study and other comparable studies. They also evaluated species resolution for different methods with various barcodes combinations and compared the ability of species identification based on plant DNA barcoding with geographically bounded sampling. Moreover, they evaluated the ability of DNA barcoding in Xishuangbanna Nature Reserve.
The researchers found that the best barcode region for PCR and sequencing was rbcL, followed by trnH–psbA, while matK and ITS obtained relative low PCR and sequencing success rates. However, ITS performed best for both species and genus identification.
Compared with the core DNA barcodes rbcL and matK, the species-level identification results for trnH–psbA and ITS were more successful. The researchers thus recommended using these two barcodes in combination as the preferred barcodes for tropical tree species in southwest China.
The study is the first attempt to barcode a local tropical tree flora from the Xishuangbanna Nature Reserve in Southwest China. The creation of the study provides a local platform for a broad range of applications that are reliant on large-scale species identification.
The study entitled “Application of DNA Barcodes in Asian Tropical Trees– A Case Study from Xishuangbanna Nature Reserve, Southwest China” has been published in PLoS ONE.
Key Words
DNA barcoding, tree species, identification, taxonomic, tropical, nature reserve
Contact
LI Jie, Ph.D Principal Investigator
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
Tel: 86 871 65144431
Fax: 86 871 65160916
E-mail: jieli@xtbg.ac.cn
