Response Of Photosynthesis Of Tomato Plants Grown On The Nutrient Solution With Different Phosphate And Ca～(2+) Levels To Chilling Stress

Chilling stress often occur in vegetable production, which cause a drastic decline in yield and quality of vegetable. Sufficient mineral nutrient supply can improve capacity of chilling tolerance.In our experiments, it was studied photosynthesis to chilling of tomato plants grown on nutrient solution with different phosphorus and Ca2+ concentration.The experiment I showed a deficit of phosphate in tomato reduced plant growth, net photosynthetic rate, stomatal conductance, photochemical efficiency of PS II and electrontransport rate but intercellular CO2 concentration went up. In addition, the study indicatedthat photosynthesis of tomato plants with limited supply of phosphate were more susceptible to chilling in inhibition of capacity for carboxylation of RuBP (ribulose-l,5-biophosphate), regeneration of RuBP and regeneration of phosphorus till photoinhibition was induced where the phosphate was absence from the solution..The experiment II showed plant growth and net photosynthetic also significantlydecreased grown on Ca2+-insufficient nutrient solution.Low content of Ca2+did not affect the rate of photosynthesis to chilling but retarded their recovery after chilling, and it wasdiscovered rate of photosynthesis depended on capacity for carboxylation of RuBP rather than regeneration of RuBP.