The Research Of Medicinal Plants From Genus Gardenia Based On DNA Barcoding

Objective:DNA barcoding is a technology of rapid and accurate species identification and recognition using a sufficient variation,with relatively general,with easy expansion and relatively short DNA sequence.To test and eva1 uate the abi1 ity of nuclear gene ITS2 sequence and chloroplast rbcL,matK and psbA barcoding sequences.To find new methods to identify the species of gardenia.Methods:Four different DNA barcode(ITS2?rbcL?matK?psbA)sequence was amplified by PCR and sequenced bidirectionally.Sequence assembly and consensus sequence generation were performed by CodonCode Aligner.The variable sites of the sequence were statistically analyzed by PAUP4.0b10.The related data analysis was performed using software MEGA 5.0 and the phylogenetic tree was constructed by using the neighbor-joining(NJ)method.The ITS2 secondary structure was predicted using ITS2 web server.Results:The length of ITS2 sequence of Gardenia and relative plants in Rubiaceae,its adulterants was 201-235 bp.The samples with close genetic relationship were gathered together on the NJ tress,it showed monophyletic,and simultaneously distinguished from their adulterants.To compare the ITS2 secondary structure among Gardenia and relative plants in Rubiaceae,its adulterants we noticed that it was obviously distinguished from the adulterants in terms ofnumber,size,position of loop,and the angle of helix exsertion.The amplification efficiency of 16 samples was 100%.Analysis of the intraand inter-specific divergence of matK among the sequences was superior to psbA and rbcL,with higher identification efficiency.Conclusion:Gardenia jasminoides Ellis can be better identified by matK and ITS2 sequence.