不同种源地木榄光合作用对低温寒害的响应  

Response of Photosynthesis to Chill Temperature in Different Regions of Bruguiera gymnorrhiza

作　　者：吴中华 赵昊阳 曾思洁 朱俊杰[1] WU Zhong-hua;ZHAO Hao-yang;ZENG Si-jie;ZHU Jun-jie(State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources,College of Forestry,Guangxi University,Nanning 530004,Guangxi,China)

机构地区：[1]广西大学林学院,亚热带农业生物资源保护与利用国家重点实验室,广西南宁530004

出　　处：《林业科学研究》2023年第2期195-202,共8页Forest Research

基　　金：国家自然科学基金资助项目(31860109)。

摘　　要：[目的]对比研究不同种源地喜温的红树植物木榄(Bruguiera gymnorrhiza (L.) Savigny)光合作用光、碳反应对低温寒害胁迫的响应及其差异。[方法 ]以我国深圳福田(FT)、福建云霄(YX)及日本冲绳(UR)3个不同地区(最冷月平均温度分别为14.1、13.3、16.1℃)采集的木榄果实萌发的5年生幼树为材料,分别测定自然常温(20℃)和低温寒害(10℃)条件下它们的叶绿素荧光特性和光合气体交换特性。[结果 ](1)和常温相比,经低温寒害胁迫处理3 d后,FT、UR、YX的光系统Ⅱ(PSII)凌晨最大光能转换效率(Fv/Fm)分别降低了39.04%、25.69%、22.83%;光系统Ⅰ(PSⅠ)最大光能转换效率(Pm)分别降低了21.80%、20.19%、42.84%。经低温后,UR、YX的PSII有效光化学量子产额(Y(II))占比均下降,3类木榄的非调节性能量耗散(Y(NO))比率均上升,以YX上调比例最大;3类木榄的PSⅠ有效光化学量子产额(Y(I))均下降,UR、YX的非调节性能量耗散(Y(NA))占比轻微下调。(2)经寒害处理后,FT、UR、YX的净光合速率(Pn)分别降低92.12%、97.50%、86.44%,蒸腾速率(Tr)、气孔导度(Gs)也相应下降,三者显著正相关;3类木榄的气孔限制值(LS)均显著降低,而胞间CO_(2)浓度(Ci)显著升高。(3)Fv/Fm、Pn和水分利用效率相互间呈显著正相关。[结论 ]无论是光合作用的光反应还是碳反应,3类木榄均表现出对寒害的高敏感,短期低温处理PSII即受到显著抑制,PSI则相对稳定。寒害条件下,非气孔因素比气孔因素对碳同化速率的限制更大。从3类木榄的光合作用对寒害的综合效应看,FT受寒害冲击最大,而YX受害相对较轻,种源地温度条件与红树光合耐寒性密切关联。[Objective]This study aims to compare the photosynthetic responses and carbon assimilation of the thermophilic mangrove plant Bruguiera gymnorrhiza(L.)Savigny from different regions under chilling stress.[Method]The 5-year-old seedlings were collected from three different provenances Futian(FT)in Shenzhen,Yunxiao(YX)in Fujian and Okinawa(UR)in Japan(the average temperature of the coldest month was 14.1,13.3,and 16.1℃,respectively).The seedlings were treated under normal temperature(20℃)and chilling temperature(10℃).For each treatment,the chlorophyll fluorescence properties and gas exchange were monitored.[Result](1)Compared with normal temperature treatment,after 3 days of chill temperature and cold stress treatment,the maximum light energy conversion efficiency of photosystem II(PSII)(Fv/Fm)in FT,UR,and YX decreased by 39.04%,25.69%,and 22.83%,respectively.The maximum light energy conversion efficiency of photosystem I(PSI)(Pm)decreased by 21.80%,20.19%and 42.84%,respectively.Under low temperature treatment,the proportion effective photochemical quantum yield of PSII(Y(II))of UR and YX all decreased,and the ratio of non-regulatory energy dissipation(Y(NO))of the three types of B.gymnorrhiza all increased,and the proportion of YX increased the most.The effective photochemical quantum yield of PSI(Y(I))of B.gymnorhiza from the three regions decreased significantly,and the proportion of non-regulated energy dissipation(Y(NA))of UR and YX decreased slightly.(2)After 4 days of cold damage treatment,net photosynthetic rate(Pn)of FT,UR and YX decreased by 92.12%,97.50%and 86.44%,respectively.Transpiration rate(Tr)and stomatal conductance(Gs)also decreased and Pn,Tr and Gs were positively correlated.The stomatal limitation value(LS)of the three types of B.gymnorhiza decreased significantly,while the intercellular CO_(2) concentration(Ci)increased significantly.(3)Fv/Fm,Pn and water use efficiency were significantly positively correlated with each other.[Conclusion]Regardless of the photoreaction of photosynthesis

关 键 词：红树植物 叶绿素荧光特性 光合气体交换特性 低温胁迫 同质园 

分 类 号：S718.43[农业科学—林学]