缺镁对菜薹光合作用特性的影响  

Effects of Magnesium Deficiency on Photosynthesis Characteristic of Flowering Chinese Cabbage

作　　者：刘厚诚[1] 陈细明[1] 陈日远[1] 宋世威[1] 孙光闻[1] 

机构地区：[1]华南农业大学园艺学院,广州510642

出　　处：《园艺学报》2006年第2期311-316,共6页Acta Horticulturae Sinica

基　　金：广东省教育厅产学研结合重点项目(cgzhzd0406)

摘　　要：研究了缺镁对菜薹光合作用特性的影响,结果表明,菜薹叶片净光合速率(Pn)、气孔导度和蒸腾速率的日变化均呈单峰曲线变化,且均随缺镁程度的加大而降低,缺镁还使Pn的高峰提早出现;缺镁降低了叶片的光补偿点、光饱和点和饱和光强下的Pnmax;缺镁使叶片的CO2补偿点提高,CO2饱和点下降(Mg1mmol·L-1)或提高(Mg0),饱和CO2下的Pnmax下降。菜薹叶片细胞间隙CO2浓度的日变化、对光强和外界CO2浓度的响应受缺镁处理的影响很小,表明缺镁菜薹光合作用主要是受非气孔限制。The effects of magnesium deficiency on photosynthesis characteristic of flowering Chinese cabbage （Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee） were studied. Net photosynthesis rate （Pn）, stomatal conductance and transpiration rate changed creased with the decrease of magnesium supply. The Pn peak in one-peak curve in daytime, and those dereached earlier in Mg-deficiency leaves. Light compensation point, light saturation point and Pn maximum at saturated light decreased in Mg-deficiency leaves. CO2 compensation point increased, CO2 saturation point decreased （ Mg 1mmol·L^-1 ） or increased （ Mg0）, Pn maximum at saturated CO2 concentration decreased in Mg-deficiency leaves. There were little effects in the changes of intracellular CO2 concentration （Ci） in daytime, the response of Ci to light and CO2 concentration by Mg-deficiency, those indicated that photosynthesis inhibition in flowering Chinese cabbage by Mg-deficiency was mainly due to non-stomatal factors.

关 键 词：菜薹 缺镁 光合作用 

分 类 号：S634.5[农业科学—蔬菜学]