有机生产系统中甜瓜果实发育和糖分积累研究

Fruit Development and Sugar Accumulation of Muskmelon in Organic Farming System

研究了有机和常规生产系统中不同施肥水平对网纹甜瓜果实发育和糖分积累的影响。结果表明:有机和常规生产系统以及施肥水平都未改变甜瓜果实发育和糖分积累规律。果实鲜重和果肉厚度的增长均呈"S"形曲线变化,可溶性固形物(TSS)和糖分积累呈二次型曲线变化。甜瓜果实在进入成熟期前,以葡萄糖和果糖积累为主,进入成熟期,蔗糖积累迅速,总糖含量持续上升。果实TSS增长趋势与总糖相同,两者呈极显著正相关(春季r=0.884**,秋季r=0.958**)。春季有机生产甜瓜采收期的果实重量显著高于常规生产,而秋季两者差异不显著。生产系统和施肥水平对果实TSS和糖分含量都没有影响。由于春季甜瓜果实发育时段的积温高,采收期果实重量和果肉厚度分别比秋季高28%和9.0%。甜瓜果实的生长量受积温的影响较大,有机生产系统和施肥水平不影响果实糖分积累。

The effects of different fertilizer amounts on fruit development and sugar accumulation of muskmelon under organic and conventional farming systems were studied in two growing seasons. The results showed that both the production system and fertilizer amount did not change the regulation of fruit growth and sugar accumulation. The fruit fresh weight and pulp thickness of muskmelon increased as ＂S＂ style growth curve, and the total soluble solid （TSS） and sugar accumulated according to quadratic functions. The fruit mainly accumulated glucose and fructose before entering the mature stage and later sucrose accumulated remarkably, thus the total sugar content rose continuously. The total sugar content and TSS were positively correone at the harvest time, while in autumn there was no difference between the two farming systems. Both the production system and fertilizer amount had no effects on fruit TSS and sugar content. The mature fruit weight and pulp thickness in spring were 28% and 9.0% larger than those in autumn due to larger growing degree days during the fruit development period. All this indicated that the fruit growth of muskmelon was mainly affected by growing degree days, while farming system and fertilization had no effect on fruit sugar accumulation.