荞麦属植物MAPK基因片段序列比较与进化关系研究

丝裂原活化蛋白激酶(MAPK)是植物MAPK级联途径中的重要信号分子。为了研究荞麦属MAPK基因序列变异以及种间进化关系,对荞麦属8个野生种共25份材料的MAPK基因进行特征引物PCR扩增、测序和序列比较分析。结果发现,荞麦属植物种间MAPK基因PCR扩增片段序列较为保守,8个野生种共25份材料中多态位点为125个,不变位点为680个。其中,12份野生苦荞MAPK基因片段序列多态位点S仅为32个,说明荞麦属植物种内MAPK基因序列高度保守。聚类分析发现野生甜荞与左贡野荞被聚为一类。野生苦荞、毛野荞、大野荞、金荞麦、细柄野荞和硬枝万年荞被聚为一大类;其中,细柄野荞和硬枝万年荞被聚在一起,其次与金荞麦聚在一起;毛野荞与大野荞被聚在一起。研究结果可为荞麦属植物MAPK基因功能以及种间遗传多样性与进化关系研究提供理论依据。

Sequence analysis of MAPK gene fragment and phylogenetic relationship of genus Fagopyrum

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.