砷对小麦生长和光合作用特性的影响  

Growth and photosynthesis characteristics of wheat (Triticum aestivum L.) under arsenic stress condition

作　　者：刘全吉[1] 孙学成[1] 胡承孝[1] 谭启玲[1] 

机构地区：[1]华中农业大学微量元素研究中心,武汉430070

出　　处：《生态学报》2009年第2期854-859,共6页Acta Ecologica Sinica

基　　金：教育部新世纪优秀人才支持计划资助项目(NECT-04-0731);国家"十一五"支撑计划课题资助项目(2008bada7B03)

摘　　要：研究了水培条件下砷对小麦根系和地上部分生长速率、光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)和蒸腾速率(Tr)的影响。结果表明,随着营养液中砷浓度的提高,小麦根长生长量和地上部分生长量较对照减少;鲜重和砷的浓度呈显著负相关。在0～90mg/L砷处理内,Pn、Gs、Tr都随砷的浓度的提高而降低;Ci呈先降低,后升高的变化。在As≤30mg/L时Ci逐渐降低,气孔限制值Ls升高,使Pn下降,造成气孔性限制;而As>30mg/L时,Ci升高,气孔限制值Ls下降,Pn降低,造成了非气孔性限制。叶片水分利用效率WUE和气孔限制值Ls在As≤30mg/L时变化一致,都有所升高;但是当As>60mg/L时,小麦趋于死亡,水分利用率降低。叶绿素含量在0～10mg/LAs处理内,差异不显著,在较高砷浓度(As>30mg/L)时叶绿素显著下降。这说明较低浓度的砷不会抑制小麦叶绿素的合成。砷主要是毒害小麦根系生长,造成植株体光合作用的气孔性限制和非气孔性限制出现,最终影响小麦的生长和发育。A hydroponic experiment was employed to study the effects of arsenic addition on the growth of wheat （ Triticum aestivum L. ） and its photosynthesis characteristics, such as net photosynthesis rate （Pn）, stomatic conductance （Gs）, intercellular CO2 concentration （ Ci）, and transpiration rate （Tr）. The results showed that addition of As in the hydroponic solution decreased the growth of root and shoots and the fresh biomass of roots and shoot was negatively related to the As concentration added, with the correlation coefficient （R2） being 0. 927 and 0. 9086, respectively. With increasing of As concentrations from 0 to 90 rag/L, Pn, Gs and Tr decreased significantly. When As was less than 30 mg/L, the Ci decreased gradually, which resulted in the increase of stomatal limitation values （Ls） and thus the decrease of Pn to form the limitation of stomat. However, when As was greater than 30 mg/L, the increasing of Ci induced the decease of Ls and Pn, and thus the limitation of non-stomat. The water unitilization efficiency （WUE） and Ls of wheat leaves increased at As 〈 30 mg/L, but the WUE deceased at As 〉 60 mg/L due to the arsenic toxicity in wheat. The content of chlorophyll had no changes at As of 0 -- 10 mg/L, but decreased significantly at As of 〉 30 mg/L. The results suggested that arsenic mainly inhibited the growth of roots and induced the limitation of both stomat and non-stomat to finally influence growth and development of wheat.

关 键 词：小麦 砷 光合速率(Pn) 气孔导度(Gs) 胞间CO2浓度(Ci) 蒸腾速率(Tr) 叶绿素 

分 类 号：S512.1[农业科学—作物学]