盐胁迫对高粱幼苗光合作用和荧光特性的影响  

Impacts of Salt Stress on Characteristics of Photosynthesis and Chlorophyll Fluorescence of Sorghum Seedlings

作　　者：孙璐[1] 周宇飞[1] 李丰先[1] 肖木辑[1] 陶冶[1] 许文娟[1] 黄瑞冬[1] 

机构地区：[1]沈阳农业大学农学院,沈阳110866

出　　处：《中国农业科学》2012年第16期3265-3272,共8页Scientia Agricultura Sinica

基　　金：国家现代农业产业技术体系建设专项资金(CAR-06-02-02)

摘　　要：【目的】研究盐胁迫对不同高粱品种幼苗光合作用及叶绿素荧光参数的影响,为高粱栽培管理、耐盐品种的选育及耐盐胁迫人工调控提供理论依据。【方法】以高粱耐盐品种(辽杂15号)和盐敏感品种(龙杂11号)为材料,人工气候箱内营养液培养,湿度60%,光照/黑暗为12 h/12 h,光照强度为134μmol·m-2·s-1,昼/夜温度为28℃/25℃。从3叶期开始进行NaCl处理(NaCl浓度为0、50、100、150、200 mmol·L-1),研究盐胁迫下高粱幼苗光合作用和叶绿素荧光参数的变化。【结果】低浓度NaCl(50 mmol·L-1)胁迫可以增加叶绿素含量,但是高浓度NaCl(100—200 mmol·L-1)胁迫明显降低叶绿素含量;盐胁迫使净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、最大荧光(Fm)、Fv/Fo、Fv/Fm、Fv′/Fm′、光化学猝灭系数(qP)下降,初始荧光(Fo)和非光化学猝灭系数(NPQ)提高,低浓度盐胁迫(50 mmol·L-1 NaCl)使胞间CO2浓度(Ci)降低,高浓度则相反。辽杂15号受盐胁迫的影响程度小于龙杂11号,表现出较好的耐盐性。【结论】50 mmol·L-1浓度的低盐胁迫对高粱幼苗的影响不明显,光合速率下降的主要原因是气孔限制;100—200 mmol·L-1浓度的高盐胁迫对高粱幼苗有很大影响,引起光合速率下降的主要原因是非气孔限制。盐胁迫下,耐盐品种能有效保护内部的光合机构,增强对盐胁迫的适应性。[ Objective ] The impacts of salt stress on the photosynthesis and chlorophyll fluorescence parameters of sorghum seedlings were studied for providing a foundation for sorghum cultivation, breeding and artificial regulation of salt stress. [Method] Salt tolerant cultivar （Liaoza 15） and salt sensitive cultivar （Longza 11 ） were incubated in the nutrient solution at humidity of 60%, light/dark of 12 h/12 h, illumination of 134 μmol.m^-2.s^-1 and 28℃/25℃ of day/night. NaC1 was added into the solution at 3-leaf stage and NaCI concentration levels at 0, 50, 100, 150 and 200 mmol.L1, respectively. The response of sorghum seedlings to NaCI stress was assessed by measuring the photosynthesis and chlorophyll fluorescence parameters of seedlings. [Result] Low NaCI concentration （50 mmol.L^-1） increased the chlorophyll content, and high NaC1 concentration （100-200 mmol.L^-1） reduced the content substantially. Salt stress reduced Pn, Gs, Tr, Fm, Fv/Fo, Fv/Fm, Fv＇/Fm＇ and qp, and increased Fo and NPQ. Low NaCI concentration （50 mmol.L^-1） reduced Ci, and high NaC1 concentration （100-200 mmol.L^-1） increased it. The adverse impact of salt stress on Liaoza 15 was less than on Longza 11. [Conclusion] The small reduction in net photosynthesis rate caused by 50 mmol.L^-1 NaC1 stress was considered to be a result of non-stomatal restriction; but increased stomatal restriction with increased NaC1 concentration resulted in more severe reductions in photosynthesis. Under salt stress, salt tolerant cultivar could protect the photosynthetic organs more effectively than salt sentitive cultivar and thus improve the production of sorghum in salt affected areas.

关 键 词：高粱 盐胁迫 光合作用 叶绿素荧光 

分 类 号：S514[农业科学—作物学]