Localization of sugar content in watermelon fruit treated with shoot heating

西瓜（Citrullus lanatus Matsumu）果实附近的芽。从花后5天（DAA）开始持续加热至夜间至少30℃。上午0 ~ 6时，塑料大棚内温度在12.7 ~ 17.2℃之间波动，近芽受热的果实（称为受热果实）表面温度比对照平均高0.8℃，受热果实果肉温度比对照高1.0 ~ 1.5℃。加热后的水果果肉色素沉着加快。加热后的果实细胞尺寸小于对照果实。加热后果实的蔗糖磷酸合成酶（SPS）活性高于对照果实。加热后果实的平均蔗糖和果糖含量高于对照。因此，我们有理由认为，在果实附近加热生芽可以加速细胞的扩大和成熟速度，从而导致果实中SPS活性的增加和蔗糖含量的增加，特别是果实的外部部分。

Shoots near fruits of watermelon (Citrullus lanatus Matsumu. et Nakai) were continuously heated from 5 days after anthesis (DAA) to a minimum of 30 - C during night. Temperatures in a plastic greenhouse during 0 a.m. to 6 a.m. fluctuated between 12.7 - 17.2 - C, and the temperature of the surface of the fruit, whose near shoots were heated (designated as a heated fruit) during these hours, was higher by 0.8 - C on the average than that of the control, and also the temperature of the flesh of the heated fruit was 1.0 - 1.5 ℃ higher than that of the control fruit. Pigmentation of the flesh of the heated fruit was accelerated. Cell size of the heated fruit was smaller than that of the control fruit. Sucrose phosphate synthase (SPS) activity of the heated fruit was higher than that of control fruit. The mean sucrose and fructose content of the heated fruit was higher than that of the control. Therefore, it is reasonable to consider that heating bearing shoots near fruits can accelerate the rate at which cells enlarge and mature, which causes an increase in SPS activity and an increase in the sucrose content in the fruit, especially the outer portions of the fruit.