Abstract: Four Paspalum vaginatum cultivars were used in this study to investigate the effect of low temperature stress on Paspalum vaginatum physiological response,and then we evaluate the cold resistance of these four cultivars. The results showed that the leaf chlorophyll content increased with the time of chilling treatment and PL,Sa had higher chlorophyll content than other two cultivars. Relative electrolyte leakage,MDA content increased under low temperature condition. After 28 d of treatment,relative electrolyte leakage and MDA content in Sa cultivar are significant lower than that in other three cultivars,respectively. H₂O₂ and O₂^- content increased under low temperature stress. No significant difference of O₂^- was found between four cultivars,whereas PL and SP had significantly lower H₂O₂ content compare with other two cultivars. SOD activity of all cultivars tends to remain consistent first increase,second decrease and then increase. POD activity increased in all cultivars under low temperature condition. CAT and APX activities were decreased in all cultivars under low temperature condition. No significant difference of CAT activity was found between four cultivars whereas APX activity in SI cultivars was significantly higher than that in other three cultivars. Taken together,Sa has better cold resistance than the other three cultivars.

Key words: Low temperature stress, Paspalum vaginatum, Antioxidant enzyme, Reactive oxygen species

摘要： 为比较不同品种海滨雀稗的抗寒性，以4个品种的海滨雀稗为供试材料，探讨低温胁迫（4℃）对海滨雀稗的生理影响，并对4个品种的海滨雀稗的抗寒性进行了比较。结果表明低温胁迫能够使海滨雀稗的叶绿素含量增加，处理28d后，PL和Sa的叶绿素含量最高。低温胁迫能够使海滨雀稗的相对电导率和MDA含量增加，在处理第28 d时，Sa的相对电导率和MDA含量显著低于其他品种。海滨雀稗的H₂O₂和O₂^-含量随着低温处理而增加，处理28 d后4个品种间的O₂^-含量没有显著差异，PL和SP品种的H₂O₂含量显著低于其他两个品种。低温使海滨雀稗的SOD活性呈现先升后降，然后再升高的趋势，处理后第28 d，4个品种间没有显著差异；低温胁迫能够使海滨雀稗的POD活性升高，但品种间没有显著差异；低温可以降低海滨雀稗CAT和APX的活性，其中CAT活性4个品种之间没有显著差异，而SI品种的APX活性显著高于其他品种。综合各项生理指标，Sa品种的抗寒性较好。

关键词: 低温胁迫, 海滨雀稗, 抗氧化酶, 活性氧