太子参脱病毒苗的核糖体ITS序列研究

Sequence analysis of rDNA ITS of de-virus seedlings of Pseudostellaria heterophylla

目的研究太子参脱病毒苗与外界苗rDNAITS区碱基序列的异同。方法运用PCR直接测序法对9种太子参脱病毒苗和4种外界苗的rDNA ITS区(包括ITS1、5.8S、ITS2)碱基序列进行了序列测定。结果太子参脱病毒苗与外界苗的5.8S碱基序列完全一致,变异位点基本上位于ITS1的起始端与ITS2的终止端,其中江苏溧阳和安徽宣城的脱病毒苗变异位点较多。使用UPGMA法构建了系统发生树,从分子生物学角度说明了它们之间的内在联系。结论rDNA ITS碱基序列的比较分析从分子水平上进一步阐明了脱病毒苗的遗传稳定性。

Objective To study rDNA ITS sequence similarities and differences between the de-virus seedlings and outside seedlings of Pseudostellaria heterophylla. Methods The sequences of ITS region （including ITS1, ITS2, and 5.8S） from nine de-virus seedlings and four outside seedlings were studied by the method of DNA sequence analysis. Results There were the same sequences in 5.8S region between the de-virus seedlings and outside seedlings of P. heterophylla. Variable sites lay in the initial position of ITS1 and termination of ITS2 basically. The de-virus seedlings from Liyang （Jiangsu Province） and Xuancheng （Anhui Province） had more variable sites. Phylogenetic dendrogram based on ITS was constructed by using UPGMA methods, which showed the inherent relation at the level of molecular biology. Conclusion The analysis of rDNA ITS of P. heterophylla has further clarified the inherit stability of de-virus seedlings at the molecular level.