Effect of low temperature stress on physiological and biochemical characteristics of Lycopersicon hirsutum seedlings.

In order to improve the theory of water-saving irrigation and environment control in solar greenhouse in the north,changes in transpiration rate of tomato which were planted in the pots in growth period were simulated by Penman-Monteith equation.The results showed that the daily variation of transpiration of tomato fruiting was the maximum,tomato seedling is the minimum,the water demand in fruiting period is 14 times of the flowering and seedling period.The daily variation of transpiration rate of seedling period reached a maximum of 8 g·h-1 at 12:30.The daily variation of the maximum transpiration rate was 11 and 45 g·h-1 at 11:30 and the minimum transpiration rate was 3 and 20 g·h-1 at 12:30 under the flowering and fruiting period,respectively.The transpiration rate of tomato in the greenhouse in north was simulated by leaf area index equation:y=0.194e0.018x,x is planting date(0≤x≤160).Between simulated and observed values of 1:1,the correlation coefficient of determination R2 is 0.885,standard error is 0.002 g·m-2·s-1,the simulation results were good.