The Preliminary Study On RDNA ITS Sequences Of Three Kinds Of Medicinal Mangrove Plants

Objective: To study the genetic character of ITS sequences of medicinal mangrove plants from different sources and to set up specifications of the identification of germplasm resources of medicinal mangrove plants on the molecular level, through sequencing and contrasting the rDNA ITS of three kinds of medicinal mangrove plants from Zhuhai and Hainan called Kandelia candel, Acanthus ilicifolicus and Aegiceras corniculatum. Methods: (1)The genomic DNA of Kandelia candel, Acanthus ilicifolicus and Aegiceras corniculatum from Zhuhai and Hainan was extracted by modified CTAB method. (2) The rDNA ITS was amplified by nPCR with eukaryotic consensus primers. (3) PCR products were puried with a PCR purification kit, and then send the purified products to the sequencing company. (4) The sequencing results were analyzed by the software called Clustral X in order to found out the differences of ITS sequences of the three kinds of mangrove plants from different sources. (5)The rDNA ITS sequences of Kandelia candel, Acanthus ilicifolicus and Aegiceras corniculatum were submitted to GenBank. Results: (1)Using the modified CTAB method, the fragments of Kandelia candel, Acanthus ilicifolicus and Aegiceras corniculatum DNA were about 23kb, the eletrophresis bands were integrity and their OD_260/280 were between 1.62 and 1.85, which meet the request of PCR model. (2) The electrophoresis band pictures of ITS1 and ITS2 sequences were clear and the length were between 200bp and 400bp. (3) The electrophoresis band pictures of the puried PCR products were clear. (4) The length of the rDNA ITS sequences of Kandelia candel, Acanthus ilicifolicus and Aegiceras corniculatum were 598bp, 647bp and 653bp from Zhuhai and were 600bp, 636bp and 653bp from Hainan, respectively. (5)The rDNA ITS sequences of Kandelia candel, Acanthus ilicifolicus and Aegiceras corniculatum from Zhuhai and Hainan have 32, 51 and 13 variable sites, 20, 15 and 6 insertion(or deletion) sites, respectively. (6)The GenBank submission numbers of rDNA ITS sequences of Kandelia candel are FJ976670(Zhuhai) and GQ141551(Hainan); Acanthus ilicifolicus are FJ976671 (Zhuhai) and GQ141552(Hainan); Aegiceras corniculatum are FJ976668(Zhuhai) and FJ976669(Hainan). Conclusion:The rDNA ITS sequences of Kandelia candel, Acanthus ilicifolicus and Aegiceras corniculatum were obtained for the first time; The differences of ITS sequences of the three kinds of medicinal mangrove plants from different sources provide molecular evidences for the identification of germplasm resources of Kandelia candel, Acanthus ilicifolicus and Aegiceras corniculatum; The rDNA ITS sequencing results can be used as one of molecular marker for the identification of germplasm resources of medicinal mangrove plants.