Effects of phosphorus and chilling under low irradiance on photosynthesis and growth of tomato plants

Abstract

To determine the effects of phosphorus nutrition on chilling tolerance of photosynthetic apparatus, tomato (Lycopersicon esculentum Mill. cv. Kenfengxin 2002) plants were raised under different P contents and subjected to 7 d of chilling at 9/7 °C. After chilling (2 h or 7 d) plant growth, P content in tissue, gas exchange and chlorophyll fluorescence were measured. Decreasing P concentration [P] in the nutrient solution markedly reduced plant growth and the chilled plants exhibiting higher optimum [P] than the unchilled plants. Decreasing [P] significantly decreased light saturated net photosynthetic rate (PNsat), maximum carboxylation velocity of Rubisco (Vcmax), maximum potential rate of electron transport contributed to Rubisco regeneration (Jmax), quantum efficiency of photosystem (PS) 2 (ΠPS2) and O2 sensitivity of PNsat (PSO2) and this trend was especially apparent in chilled plants. © 2009 Springer Science+Business Media B.V.