Effects on Sucrose Metabolism,Dry Matter Distribution and Fruit Quality of Tomato Under Water Deficit

Four irrigation treatments were designed with 2,4,6 and 8 d intervals to irrigate, respectively. Watering was stopped when the reading of the moisture tension sensor reached zero. The results indicated that glucose and fructose content of tomato's fruit were increased but sucrose content was decreased with fruit growth and development. In different stages, carbohydrate content of tomato fruit in the treatment 3 was the highest, in the treatment 2 was higher, and in the other treatments was the lowest. SS(sucrose synthase)activity was decreased but SPS(sucrose phosphate synthase)activity was increased with development of tomato. SS and SPS activity were increased but acid invertase and neutral invertase activity of ripe stage were decreased under deficit irrigation. Glucose and fructose content were increased in leaves of tomato under water deficit. Soluble sugars, organic acid and the ratio of sugar/acid in tomato fruits were increased and dry matter accumulation of plant was enhanced under water deficit. But the growth of fruits upside the plant and its dry matter accumulation were badly affected under water stress.

亏缺灌溉对番茄蔗糖代谢和干物质分配及果实品质的影响

在设施内设置4个灌水处理,分别间隔2(CK)、4(处理1)、6(处理2)和8d(处理3)浇1次水,均以浇水后土壤水分张力计回零为准。结果表明,番茄果实中葡萄糖和果糖的含量随生长发育的进行而逐渐提高,蔗糖含量下降;各时期处理3番茄果肉中糖分含量最高,其次为处理2,其余2处理果实糖分含量最低。蔗糖合成酶活性呈下降趋势,蔗糖磷酸合成酶活性逐渐升高,水分亏缺提高了这2种酶的活性,但降低了成熟期酸性转化酶和中性转化酶活性。亏缺灌溉提高了番茄叶片中葡萄糖和果糖含量,同时提高了果实中的可溶性糖、有机酸的含量及糖酸比,增加了植株的干物质积累,但严重亏缺灌溉可明显影响植株上部果实的生长和干物质积累。