短期紫外线(UV-C)辐射对早熟禾生理特性的影响

Effects of short-term UV-C radiation on physiological characteristics of Poa pratensis

对早熟禾Poa pratensis进行短期紫外线(UV-C)照射,结果表明:照射时间小于6 h,紫外线诱导早熟禾叶绿素含量增加,照射时间超过6 h后叶绿素含量下降,这种变化趋势主要是由叶绿素a含量变化导致的,而叶绿素b含量在照射10 h内变化很小。照射时间在6h内丙二醛(MDA)的含量上升,然后有所下降。照射时间在6 h以内超氧化物歧化酶(SOD)的活性持续下降,然后上升;过氧化氢酶(CAT)的活性变化与SOD相似,但有波动性变化;过氧化物酶(POD)的含量则在照射4h内持续下降,然后一直呈上升趋势。研究表明,单次UV-C照射时间6 h是使早熟禾的生理过程发生转折的时间阈值。

Poa pratensis was radiated for 10 h by UV-C. The protective enzyme activity, MDA and chlorophyll were measured after 0,2,4,6,8,10 h of radiation. The chlorophyll content increased before 6 h radiation and decreased after. This mainly caused by the change of chlorophyll a, chlorophyll b almost did not change in this study. MDA content had the same tendency as chlorophyll. SOD activ- ity decreased within 6 h radiation and increased with increasing radiation time. CAT activity was similar to that of SOD. POD activity decreased within 4 h radiation and increased after. This study showed that UV-C radiation could influence physiological activities and 6 h UV-C radiation seemed to be a threshold for P. pratensis.