草业学报2016，Vol.25Issue(5)：49-59,11.DOI:10.11686/cyxb2015472
水淹胁迫对狗牙根光合、生长及营养元素含量的影响
Effects of flooding on photosynthesis,growth and nutrient content of Cynodon dactylon
摘要
Abstract
A flooding simulation experiment was conducted to detect the effects of flooding on photosynthesis, growth and nutrient concentrations of Cynodon dactylon .Two flooding-depth levels,surface flooding (SF)and total flooding (TF)were imposed,and compared with control (CK).Net photosynthetic rate (P n ),stomatal conductance (G s ),transpiration rate (T r )and stomatal limitation (L s )of C.dactylon under SF were signifi-cantly lower than those for the CK treatment,while the intercellular CO2 concentration (C i )was significantly higher.However,water use efficiency (WUE)did not differ significantly between SF and the CK treatment. Under SF,root length,root surface,root volume,branch number,leaf number,root biomass,leaf biomass and root∶shoot ratio were all significantly reduced,whereas plant height,base diameter,stem biomass and total biomass did not differ significantly between SF and CK.Under TF,root length,root surface,root vol-ume,plant height,branch number,leaf number,root biomass,base diameter,stem biomass and total bio-mass were also significantly lower than those of CK.Compared to CK,root nutrient concentrations (N,P,K, Fe,and Mn)of C.dactylon under SF and TF were increased,whereas Cu content was significantly decreased. Leaf concentrations of Fe and Mn under SF were significantly increased,but the contents of P,K and Cu under SF were significantly decreased,compared to CK.Thus flooding resulted in significant reductions in photosyn-thesis,growth,and uptake of nutrients of C.dactylon.The reduction of leaf concentrations of P,K,and Cu and the rise in leaf concentrations of Fe,and Mn could account for the reduction in P n .However,C.dactylon was able to improve the absorption of N,P,and K,promote stem elongation and maintain a high net photo-synthetic rate to cope with flooding.Additionally,when flooded,leaf N and P could potentially be directly re-leased into the water on leaf fall,which could increase the risk of eutrophication in waterways.关键词
三峡库区/水淹/狗牙根/光合/生长/营养元素含量Key words
The Three Gorges Reservoir Area/flooding/Cynodon dactylon/photosynthesis/growth/nutrient concentration引用本文复制引用
韩文娇,白林利,李昌晓..水淹胁迫对狗牙根光合、生长及营养元素含量的影响[J].草业学报,2016,25(5):49-59,11.基金项目
重庆市林业重点科技攻关项目（渝林科研2015-6），国家科技部国际合作专项（2015DFA90900），重庆市基础与前沿研究计划重点项目（CSTC2013JJB00004）和中央高校基本科研业务费专项资金（XDJK2013A011）资助。 （）
