干旱及复水对桑树叶片光合能力的影响  

Effect of drought and rewatering on the photosynthetic characteristics in Morus albaleaves

作　　者：滕志远[1] 张栩涵 张会慧[2] 马瑶 张秀丽[1] 孙广玉[1] Teng Zhi-yuan;Zhang Xu-han;Zhang Hui-hui;Ma Yao;Zhang Xiu-li;Sun Guang-yu(College of Life Science,Northeast Forest University,Harbin 150040,Heilongjiang,China;College of Resource&Environment,Northeast Agricultural University,Harbin 150030,Heilongjiang,China)

机构地区：[1]东北林业大学生命科学学院,黑龙江哈尔滨150040 [2]东北农业大学资源与环境学院,黑龙江哈尔滨150030

出　　处：《草业科学》2018年第4期848-856,共9页Pratacultural Science

基　　金：黑龙江省教育厅科学技术研究项目(12543013)

摘　　要：为研究干旱及旱后复水对桑树叶片光合能力的影响,揭示其对干旱的适应性及复水后的修复机制,以秋雨桑(Morus alba‘Qiuyu')为试验材料,采用盆栽控水法探究了桑树叶片生长及光合荧光特性。结果表明:土壤含水量为26.7%时,叶片含水量显著降低,萎蔫下垂,卷曲度、叶基角增大;桑树叶片的净光合速率、蒸腾速率以及气孔导度等主要光合气体交换参数近于0,而胞间CO_2浓度和气孔限制值升高。初始荧光、过剩光能、失活PSⅡ反应中心的热耗散量子产额、维持类囊体膜两侧质子梯度和叶黄素循环的比例、荧光量子产额和热耗散的量子产额值均升高,而最大荧光、电子传递效率和吸收光能用于光化学反应量子产额下降;复水后,叶片长势指标、主要光合气体交换参数和荧光参数值迅速恢复。这表明干旱下桑树叶片净光合速率由气孔和非气孔因素共同限制,PSⅡ反应中心部分失活,叶片通过增加叶黄素循环,荧光量子产额和热耗散来消耗过剩光能。且复水后,桑树叶片光合机构具有完善的调节修复机制,可在较短的时间内修复干旱胁迫引起的损伤。In order to detect the effects of drought and rewatering on the photosynthetic capacity and adaptive mechanism in mulberry leaves,a mulberry variety named‘Qiuyu’was employed as the experimental material,and the characteristics of photosynthesis,and fluorescence were investigated using pot tests with a water control(CK).The results showed that the water contents in the potted mulberry plant leaves were significantly lower than that in the CK;leaf wilting,curling and drooping,and the leaf base angle was increased when the soil water content was reduced to 26.7%,and the net photosynthetic rate,stomatal conductance,and transpiration rate were close to zero,while the values of stomatal limitation and intercellular CO 2 concentration were increased.In addition,the excess light energy,ratio of dependent thylakoid membrane on both sides of the proton gradient,proportion of xanthophyll cycle,fluorescence quantum yield,heat dissipation quantum yield,and the original fluorescence were increased.Additionally,the maximum fluorescence,proportion of absorbed light energy in to the photochemical reaction yield,and the electron transport rate were decreased.After rewatering,the indicators of leaf growth,main parameters of photosynthesis and fluorescence in the mulberry leaves recovered quickly and returned to close to those in the CK.Our results indicated that the decrease in the net photosynthetic rate under drought stress might be caused by the stomatal and non-stomatal limitations.The PSII response center was partly inactivated,the excitation energy in mulberry seeding leaves was reduced;these responses mainly depended upon increasing ratios of the xanthophyll cycle and the quantum yields of fluorescence and heat dissipation.After rewatering,the photosynthetic apparatus in the mulberry leaves had a perfect mechanism for adapting to drought stress and repairing after injury,which could help mulberry to recover quickly in a shorter time.

关 键 词：桑树 干旱 旱后复水 光能分配 气孔限制因素 

分 类 号：Q949.737.4[生物学—植物学] Q945.11