摘要
以春末夏初南京地表实际UV-B剂量为参考,将菹草成株分别置于50、100、150和200μW·cm-2剂量的UV-B辐射下,测定其叶绿素荧光参数。结果表明:Fo、Fm在辐射早期随辐射剂量增加而递增,但后期随辐射剂量增加而递减;Fv/Fm、ΦPSII、NPQ随辐射剂量增加而递减。因此,菹草成株在遭遇UV-B辐射后,PSII反应中心出现可逆性失活或出现不易逆转的破坏,致使原初光能转换效率、电子传递速率下降,实际光化学效率降低,最终加速菹草衰亡。因此,春末夏初UV-B辐射增强可能是促进野外菹草大批衰亡的重要原因,但是否与其他环境因素之间存在联合作用机制,还需要进一步研究。
Based on the in situ UV-B doses observed in the late spring and early summer, the photosynthesis fluorescent parameters of the adult plants of Potamogeton cripus under the ultravio- let radiation stress （50, 100, 150, and 200μW · cm-2） were determined. The results revealed that Fo and Fm increased in the initial period and then decreased with the increasing the dose of UV-B radiation. Fv/Fm, φstt and NPQ consistently increased with increasing the radiation dose. The findings suggest that when the adult plants of P. cripus were irradiated under UV-B radiation, PSII reaction center was injured to reversible inactivity or irreversible damage, the light energy conversion efficiency and the electron transport rate were reduced, and the actual photochemical efficiency declined. In conclusion, UV-B radiation accelerates the decline of P. crispus, indica- ting that ultraviolet radiation might be an important factor leading to mass mortality of P. crispus in late spring and early summer. However, further research is necessary to discover whether UV-B radiation combines with other environmental factors to cause the decline of P. crispus.
出处
《生态学杂志》
CAS
CSCD
北大核心
2015年第7期1898-1904,共7页
Chinese Journal of Ecology
基金
国家自然科学基金项目(41105113
51109109)
江苏省环境演变与生态建设重点实验室开放基金项目资助
关键词
UV-B辐射
荧光参数
光能转换效率
实际光化学效率
衰亡
UV-B radiation
fluorescence parameters
energy conversion efficiency
actual photochemical efficiency
decline.
