冬季降温对菹草叶片光合荧光特性的影响  

Influences of temperature decreasing on the photosynthetic fluorescence characteristics of Potamogeton crispus in winter

作　　者：李强[1,2] 王国祥[2,3] 

机构地区：[1]重庆文理学院化学与环境工程学院,重庆402160 [2]江苏省环境演变及生态建设重点实验室,江苏南京210097 [3]南京师范大学地理科学学院,江苏南京210097

出　　处：《生态环境》2008年第5期1754-1758,共5页Ecology and Environmnet

基　　金：国家863"十五"重大科技专项(2003AA601100-2);教育部科技创新工程重大项目(705824);重庆市教委科研项目(KJ081206);江苏省环境演变及生态建设重点实验室开放基金项目(JSKLEC200801)

摘　　要：将菹草(Potamogeton cripus)石芽种植于室外水体中,萌发后选择发育程度相近的幼苗,在冬季降温期间利用水下饱和脉冲荧光仪(DIVING-PAM)测定幼苗叶片的Fv/Fm和光响应恢复曲线。结果表明,在冬季水温低于7℃的条件下菹草叶片Fv/Fm显著降低(P<0.01)。水温回复到9～10℃后,Fv/Fm逐渐增大;光强的降低有利于Fv/Fm的恢复。进一步研究植株的光响应恢复曲线发现,第4-10天,水温<7℃,菹草叶片有效荧光产量(△F v’/Fm’)的光响应能力和暗恢复能力显著下降;同时,热耗散能力和暗恢复能力也显著降低,发生光抑制的可能性增大。当水温升高到9～10℃时,△F v’/Fm’和非光化学淬灭(NPQ)随光强降低和实验天数的增加逐渐得到恢复。因而,水温9～10℃可能是冬季菹草进行正常光合作用的临界温度;菹草在低温(<7℃)、高光照条件下易发生光抑制,导致PSII受到伤害。Winter buds ofPotamogeton crispus were planted in outdoor water. After they germinated, similar seedlings were selected out. And Some photosynthetic fluorescence characteristics were in situ determined by a developed, submersible, pulse-amplitude modulated （abbreviate PAM） fluorometer, Diving-PAM during temperature decreasing in Winter. The results showed that Fv/Fm of P, crispus＇ leaves significantly decreased （P 〈 0.01） when plants were kept in lower water temperature than 7 ℃. After water temperature returned to 9 ℃ or 10 ℃, Fv/Fm gradually increased. And low irradiance density was in favor of restoration of Fv/Fm. Further researches on rapid light curves （abbreviate RLCs） and recovery of these leaves found that water temperature was less than 7 ℃ from the fourth day to tenth day, and rapid light responding ability and dark recovery ability of their efficient fluorescence yield （△Fv ＇/Fm ＇） markedly decreased. At the same time their heat dissipated ability and dark recovery ability also significantly decreased. These made it be more possibile that photoinhibition ofP. crispus＇ leaves occured. When water temperature increased to 9 ℃ or 10 ℃, △Fv ＇/Fm ＇and non-photochemical quenching （abbreviate NPQ） gradually restored with irradiance decreasing and experimental days increasing. So, water temperature of 9 ℃ or 10 ℃ may be critical point which photosynthesis of P. crispus occurs. Photoinhibition ofP. crispus＇ leaves is more possible to occure on the condition of lower temperature than 7 ℃ and high irradiance density, which will make photosystem II （abbreviate PSII） be damaged.

关 键 词：菹草 低温 光合荧光特性 

分 类 号：X173[环境科学与工程—环境科学]