中文摘要：

以贵州主栽的火龙果（Hylocereus undatus）优良品种——紫红龙为材料，探讨了甲基磺酸乙酯（EMS）浓度及处理时间对火龙果种子发芽率、发芽势及发芽指数等发芽指标的影响。结果表明：0．1％EMS处理1d的发芽势与O．1％EMS处理2d的发芽指数明显高于对照；但采用0．4％和0．6％EMS处理时，发芽势和发芽指均低于相应对照，0．6％EMS处理3d时，种子发芽率仅为23％。可见，低浓度短时间的EMS处理可提高出苗的整齐度，而较高浓度或较长时闯处理则相反；EMS对种子萌发力有一定的抑制作用，且抑制作用与浓度和处理时间呈正相关。

英文摘要：

：In order to elucidate the effect of EMS on seed germination, the germination potential, germination index, as well as germination rate were investigated of dragon fruit （Hylocereus undatus, ＇ zihonglong＇ ） seed subjected to different concentrations of EMS in the work. The results showed that, as exposure to 0.1% EMS for 1 d or 2 d, the germination potential or germination index was significantly elevated in comparison with the control （EMS-free） , respectively. Conversely, the germination potential and germination index reduced obviously when subjected to 0.6% or 0.6% EMS. The germination rate was only 23% as exposed to 0.6% EMS for 3 days. Therefore, use of low concentration of EMS for short time may improve seedling uniformity of dragon fruit, and longer exposure time or higher concentration of EMS demonstrated negative effect on seed germination. Furthermore, EMS somewhat showed inhibitory effects on seed germination ability.