植物生长调节剂处理对油菜胚根伸长期耐渍性的影响

为了解直播油菜耐渍调控机理和对田间油菜出苗和成苗的胁迫影响，以沣油737为材料，分别应用氨氧 基乙酸盐（AOA）、赤霉酸（GA3）和多效唑（PP333）浸种，应用1-甲基环丙烯（1-MCP）熏蒸吸胀种子，在胚根伸长期渍水后观测不同调节剂预处理对油菜种子出苗、幼苗生长、种子乙烯释放速率和细胞结构的影响。结果表明，胚根伸长期渍水显著降低种子出苗率和出苗指数，并抑制渍水后幼苗生长；AOA、1-MCP和GA3预处理可有效缓解渍水对油菜种子出苗的胁迫作用，其中AOA预处理对渍水后幼苗的恢复生长也具有一定的调节效应，而PP333预处理则加剧渍水对种子出苗的胁迫作用。AOA预处理可增强渍水24h后胚芽细胞自噬活性以适应渍水环境。1-MCP、AOA、GA3预处理显著降低不渍水种子的乙烯释放速率，但可减少渍水过程中种子乙烯释放的下降幅度，表明在渍水前适 当降低种子内源乙烯水平，而在渍水过程中维持种子一定水平的乙烯合成，可能有利于提高油菜种子的耐渍性。

Effects of several plant regulators on waterlogging tolerance of Brassica napus during radicle growth

 To better understand the mechanism of waterlogging on direct-seeded rapeseed (Brassica napus L.), changes of rapeseed cultivar Fengyou 737 during radicle period were investigated after waterlogging by 4 regulators pretreatments. The 4 regulators were AOA O-(carboxymethyl) hydroxylamine hemihydrochloride, for soaking], GA3 (gibberellic acid, for soaking), PP333 (paclobutrazol, for soaking), and 1-MCP (1-methyl-cyclopropene, for fumigat? ing imbibed seeds). Results showed that, waterlogging at the radicle growth significantly reduced the seedling emer? gence rate and emergence index, and inhibited the seedling growth. The pretreatments with AOA, 1-MCP and GA3 effectively relieved the waterlogging stress on rapeseed emergence, among them the pretreatment of AOA showed relatively higher promotion to seedling growth. The pretreatment of PP333 reduced the waterlogging stress on rapeseed emergence. After waterlogging for 24 hours, the cell autophagic activity increased in germs of seeds pre? treated with AOA, which could be helpful to improved stress adaptation. The pretreatments of 1-MCP, AOA and GA3 reduced ethylene release rate in seeds under non-waterlogging condition but decreased the falling range of eth? ylene release after waterlogging for 24 hours. It indicated that lowering endogenous ethylene production prior to wa? terlogging but maintaining ethylene production to certain degree might be conducive to waterlogging tolerance of rapeseed at radicle growth period.