盐胁迫对番茄果实糖含量及蔗糖代谢的影响

以番茄栽培品种辽园多丽为试材，在果实发育期进行盐胁迫〔50 mmol·L-1 NaCl以及等渗透势的NaNO3、KCl、KNO3、CaCl2和Ca（NO3）2〕处理，研究不同种类盐胁迫对番茄果实品质及蔗糖代谢的影响。结果表明：3种Cl-盐胁迫处理均提高了成熟番茄果实中可溶性固形物、可溶性糖、有机酸含量和糖酸比。盐胁迫下番茄完熟期果实各部位己糖（果糖+葡萄糖）含量增加，蔗糖转化酶（酸性转化酶+中性转化酶）活性增强，而且各处理可溶性糖和己糖含量变化与蔗糖转化酶活性变化成正比。由此可见，果实发育期盐胁迫下番茄果实可溶性糖含量的提高是由于蔗糖转化酶活性的增强|提高番茄品质的最佳盐是KCl。

Effects of Salt Stress on Sugar Content and Sucrose Metabolism in Tomato Fruit

Tomato(Lycopersicon esculentum Mill.)cultivar’Liaoyuanduoli’was used,salt stress〔50 mmol·L-1 NaCl and iso-osmotic NaNO3、KCl、KNO3、CaCl2 and Ca(NO3)2〕treatments were conducted in the fruit development period(from 20 days after flowering to fruit ripening)to study the effects of different types of salt stress on sugar content and sucrose metabolism in tomato fruit.The results showed that the three Cl- salt treatments had increased the contents of soluble solids,soluble sugar,organic acids and sugar-acid ratio in matured tomato fruit.Further analysis indicated that salt stress treatments had enhanced hexose(fructose + glucose)content in various parts of tomato fruit,strengthened sucrose invertase(acid invertase + neutral invertase)activity.Under various treatments,the changes in contents of soluble sugars and hexose had converted to direct proportion with the changes in sucrose invertase activity.Thus,under salt stress the increase of soluble sugar content in tomato fruit was due to the strengthening of sucrose invertase activity.The best salt for improving tomato quality is KCl.