Interactive Effects of Drought Stresses and Elevated CO2 Concentration on Photochemistry E

Interactive Effects of Drought Stresses and Elevated CO2 Concentration on Photochemistry

Efficiency of Cucumber Seedlings

Qing-Ming Li;Bin-Bin Liu;Yang Wu;Zhi-Rong Zou

【期刊名称】《植物学报（英文版）》 【年(卷),期】2008(050)010

【摘要】To reveal and quantify the interactive effects of drought stresses and elevated CO2 concentration [CO2] on photochemistry efficiency of cucumber seedlings, the portable chlorophyll meter was used to measure the chlorophyll content, and the Imaging-PAM was used to image the chlorophyll fluorescence parameters and rapid light response curves (RLC) of leaves in two adjacent greenhouses. The results showed that chlorophyll content of leaves was reduced significantly with drought stress aggravated. Minimal fluorescence (Fo) was increased while maximal quantum yield of PSII (Fv/Fm) decreased significantly by severe drought stress. The significant decrease of effective quantum yield of PSll (Y(Ⅱ)) accompanied by the significant increase of quantum yield of regulated energy dissipation (Y(NPQ)) was observed under severe drought stress condition, but there was no change of quantum yield of nonregulated energy dissipation (Y(NO)). We detected that the coefficient of photochemical quenching (Qp) decreased, and non-photochemical quenching (NPQ) increased