灌溉量对限根栽培番茄生长和品质的影响

Effect of Irrigation Volume on Growth and Quality of Root-limited Cultivation Tomato

为了明确灌溉量对番茄品质的调控效果,利用限根槽培无土栽培系统,对不同灌溉量(2.0、1.6、1.2、0.8、0.4 L·d^-1)下番茄的生长、叶片光合参数、产量、品质及代谢相关酶等变化规律进行研究。结果表明,减少灌溉量显著抑制了番茄的生长,降低了叶片净光合速率、气孔导度、胞间CO2浓度、蒸腾速率,单株产量和单果质量也均显著降低;但果实中葡萄糖、果糖、VC含量及糖酸比明显提高,可溶性糖和可滴定酸含量逐渐增加。灌溉量的减少降低了番茄果实中蔗糖合成酶和磷酸蔗糖合成酶活性,提高了中性转化酶和酸性转化酶的活性,从而降低了蔗糖的含量。利用熵权法和TOPSIS法相结合的方法,综合分析各项指标得出番茄在限根栽培下的最佳日灌溉量为0.8 L。

In order to reveal the effects of irrigation volume on regulating tomato growth and quality,this paper studied the changing rule of tomato growth,leaf photosynthetic parameters,yield,quality and metabolism related enzymes under different irrigation volumes(2.0,1.6,1.2,0.8,0.4 L·d^-1)using rootlimited soiless cultivation system.The results indicated that reducing irrigation volume could significantly limit tomato growth,decrease net photosynthetic rate(Pn),transpiration rate(Tr),intercellular CO2 concentration(Ci),stomatal conductance(Gs),single plant yield and single fruit weight.But,reducing irrigation volume could significantly increase the contents of glucose,fructose,and VC;improve acid-sugar ratio in fruits,and gradually increase the contents of soluble sugar and titratable acid.Reducing irrigation volume could also reduce the activities of sucrose synthetase and phosphate sucrose synthetase in tomato fruit;improve the activities of neutral invertase and acid invertase,resulting in the decrease of sucrose content.By combing entropy weight method with TOPSIS method,the paper analyzed comprehensively various indexes.The results showed that 0.8 L was the best daily irrigation volume for tomato under soiless cultivation.