大气CO_(2)浓度升高和干旱互作对谷子光合及抗旱生理特性的影响  

Interactive effect of elevated CO_(2) concentration and drought on photosynthetic and physiological indexes of foxtail millet

作　　者：刘亚静 张东升 李萍[1] 宗毓铮[1] 郝兴宇[1] LIU Yajing;ZHANG Dongsheng;LI Ping;ZONG Yuzheng;HAO Xingyu(College of Agriculture,Shanxi Agricultural University,Taigu 030801,China)

机构地区：[1]山西农业大学农学院,太谷030801

出　　处：《中国生态农业学报（中英文）》2021年第3期500-508,共9页Chinese Journal of Eco-Agriculture

基　　金：国家自然科学基金面上项目(31871517, 31971773)资助。

摘　　要：为明确谷子光合作用以及抗旱生理过程对高大气CO_(2)浓度和干旱交互作用的响应机制,在开顶式气室中(OTC)开展大气CO_(2)浓度和干旱交互对谷子影响的研究。设置两个CO_(2)浓度:环境CO_(2)浓度(400μmol·mol^(-1))和高CO_(2)浓度(600μmol·mol^(-1));两个水分处理:正常水分(70%~80%田间持水量)和干旱(45%~55%田间持水量),对高CO_(2)浓度和干旱互作下谷子光合气体交换参数、荧光动力学参数及抗旱相关生理指标的变化进行了研究。结果表明:高CO_(2)浓度可降低干旱条件下光合色素含量,加剧孕穗期谷子气孔关闭,减轻灌浆期干旱对谷子净光合速率的负效应并增加其水分利用效率。孕穗期高CO_(2)处理使正常水分处理下谷子气孔导度下降66.7%,而干旱处理下减少77.7%;灌浆期高CO_(2)使正常水分处理和干旱处理下谷子净光合速率分别增加19.0%和87.7%,水分利用效率增加37.1%和39.2%。干旱处理显著降低谷子除非光化学淬灭系数(NPQ)以外所有荧光动力学参数值,灌浆期高CO_(2)能缓解该作用。高CO_(2)处理显著减少纤维素含量和正常水分处理下过氧化物酶活性。干旱极显著升高POD活性(高CO_(2)浓度)及脯氨酸含量、可溶性总糖、淀粉含量(环境CO_(2)浓度)和纤维素含量(高CO_(2)浓度)。因此CO_(2)浓度升高能够改善谷子的PSⅡ光化学效率和提高抗氧化酶活性来增强谷子的抗旱性。There is a lack of knowledge on the interactive effects of elevated atmospheric carbon dioxide(CO_(2))concentrations([CO_(2)])and drought on the photosynthesis and physiological processes underlying foxtail millet drought resistance.An experiment was conducted in an open-top chamber with two CO_(2) treatments,ambient[CO_(2)](CK,400μmol·mol-1)and elevated[CO_(2)](ECO_(2),600μmol·mol-1),and two water treatments,normal water(relative water content was 75%-85%soil capacity)and drought(relative water content was 35%-45%soil capacity).We quantified the interactive effects of elevated CO_(2) and drought on the gas exchange parameters,fluorescence parameters,and drought-resistant physiological indicators in millet.The results showed that elevated CO_(2) could reduce the content of photosynthetic pigment under drought conditions.Elevated[CO_(2)]aggravated millet stomatal closure at the booting stage,alleviated the negative effects of drought on the net photosynthetic rate at the filling stage,and increased the water utilization efficiency.During the booting stage,elevated[CO_(2)]resulted in a 66.7%reduction in stomatal conductance under normal water conditions and a 77.7%reduction under drought conditions.During the grouting period,under normal water conditions,elevated[CO_(2)]led to a 19.0%increase in the grain net photosynthetic rate and a 37.1%increase in water use efficiency;under drought conditions,it led to an 87.7%increase in the grain net photosynthetic rate and a 39.2%increase in water use efficiency,respectively compared with that of ambient[CO_(2)].Drought significantly reduced all of the millet fluorescence kinetic parameters,except non-photochemical quenching(NPQ),and elevated[CO_(2)]alleviated this effect in the grouting period.At the booting stage,ECO_(2) and drought showed significant interactive effects on the intrinsic efficiency of photosystemⅡ(PSⅡ)(Fv/Fm'),PSⅡphotochemistry(ΦPSⅡ),and the highest photosynthetic electron transport(ETR)and photochemical quenching coefficient(qP).Elevated[CO_(

关 键 词：干旱 高大气CO_(2) 光系统Ⅱ效率 抗逆性 

分 类 号：S515[农业科学—作物学]