Abstract: Mitogen-activated protein kinase is the major signaling molecule of MAPK cascade pathway in plants. To characterize MAPK gene sequence mutations and phylogenetic relationship of genus Fagopyrum, 25 collections of 8 wild species were selected for the PCR amplification, gene sequencing and analysis of MAPK gene. The results indicated that the MAPK gene fragment sequence amplified by PCR was conservative since a total of 125 polymorphic (segregating) sites and 680 unchanged sites among 25 collections of 8 wild species of genus Fagopyrum were detected. Whereas only 32 polymorphic (segregating) sites were found among 12 collections of F. tataricum ssp. potanini indicating that MAPK gene sequence is highly conserved in intra-specie of genus Fagopyrum. Hierarchical cluster analysis indicated that F. esculentum ssp. ancestralis was clustered with F. zuogongense. By contrast, F. tataricum ssp. potanini, F. pilus, F. megaspartanium, F. cymosum, F. gracilipes and F. urophyllum were clustered as a group. F. gracilipes was clustered with F. urophyllum, and further clustered with F. cymosum. In addition, F. pilus was clustered with F. megaspartanium. These results provide the theoretical basis for research of MAPK gene, genetic diversity and evolutionary relationship of genus Fagopyrum.

Key words: Fagopyrum, mitogen-activated protein kinase, gene fragment sequence, phylogeny