关键词: 金荞麦, ITS, PCR, 序列分析

Abstract: The genetic relationship among different Fagopyrum cymosum was revealed by analyzing the internal transcribed spacer(ITS) sequences of five F. cymosum samples.The sequencing results showed that there were about 700 bp including the whole ITS₁,5.8S and ITS₂ regions.The further analysis indicated that ITS regions of five samples were 638-797 bp in length.With lack of gap as treatment,the whole ITS sequence consisted of 488 conserved sites,248 variable sites,67 information sites and 175 singleton sites.The sequence similarity among thirteen F. cymosum samples varies from 86.8% to 98.8%,and the main variation occurs on ITS₁ area.The data indicated that abundant genetic diversity existed among different sources of F. cymosum.Phylogenetic tree was constructed by neighbour-joining method,which enriched genetic diversity of buckwheat at the molecular level.Analysis results showed that F. cymosum was mainly divided into two groups,and there was some correlation between the phylogenetic distance and the locality of collection.

Key words: Fagopyrum cymosum, ITS sequences, PCR, sequence analysis