草业学报2016，Vol.25Issue(5)：40-48,9.DOI:10.11686/cyxb2015239
Ca2＋对镉胁迫下玉米幼苗生长、光合特征和 PSⅡ功能的影响
Effects of exogenous Ca2+ on growth,photosynthetic characteristics and photosystem II function of maize seedlings under cadmium stress
摘要
Abstract
To investigate how calcium relieves cadmium toxicity in maize,the effects of exogenous Ca2 + on growth properties,photosynthetic characteristics and chlorophyll fluorescence parameters of maize seedlings under cadmium stress were studied in a pot experiment.A treatment with 100 mg/L of cadmium obviously in-hibited the growth of maize seedlings,decreased the biomass of plants,and decreased the contents of chloro-phyll a,b and a+b of leaves.At the same time,the net photosynthetic rate (P n ),stomatal conductance (G s ), transpiration rate (T r ),the maximal PSⅡ efficiency (F v/F m ),photosynthetic electron transfer rate (ETR), the efficiency of excitation energy capture by open PSⅡ centers (F v′/F m′),photochemical quenching coeffi-cient (qP ),and the actual PS Ⅱ efficiency (ΦPSⅡ )were reduced whereas the intercellular CO2 concentration(C i )and non-photochemical fluorescence quenching coefficient (NPQ)were increased under cadmium stress.Supply of exogenous Ca2 + under cadmium stress promoted the growth of seedlings,increased the biomass ofplants and raised the contents of chlorophyll a,b and a+b of leaves.At the same time,P n ,G s ,T r ,F v/F m ,ETR,F v′/F m′,qP andΦPSⅡ of leaves tended to be increased with increased exogenous Ca2 + concentration,but C i and NPQ were reduced.Among different Ca2 + application rates,7 .5 to 1 0.0 mmol/L Ca2 + had the greatestalleviation of Cd toxicity effects.It is suggested that Cd stress led to a decrease in the photochemical efficiencyof PSⅡ,reduction in electron transfer,and reduction in net photosynthetic rate.Exogenous Ca2 + at appropriatecon centrations had favorable effects on seedling growth,including enhanced performance of the photosyntheticapparatus and capture of solar energy,effectively ameliorate Cd-induced depression of photosynthesis and enhancingthe resistance of maize seedlings to Cd stress.关键词
镉胁迫/玉米/钙/光合特性/PSⅡ 功能Key words
cadmium stress/maize (Zea mays )/calcium/photosynthesis characteristics/PSⅡ function引用本文复制引用
王玉萍,常宏,李成,梁延超,卢萧..Ca2＋对镉胁迫下玉米幼苗生长、光合特征和 PSⅡ功能的影响[J].草业学报,2016,25(5):40-48,9.基金项目
国家自然科学基金（31060063，31260094）和甘肃省财政厅高等学校基本科研业务费资助。 （）
