STUDIES IN WATER-SOAKED SYMPTOM IN MELON FRUIT : CHANGES IN CELL WALL SUBSTANCES AND THE PROTECTION OF THE DISORDER.

1.研究了遮荫对网纹甜瓜果实水分浸泡症状发生的影响。1)‘安得苏’甜瓜果实果胶物质的降解比‘光泽’甜瓜果肉软化更明显。3)遮荫导致细胞壁中性糖迅速降解，尤其是半乳糖、葡萄糖和木糖。这些结果表明，网纹甜瓜果实在遮荫条件下的早期软化可能是由于果胶与果胶和/或半纤维素与果胶之间的细胞壁成分连接减少所致。研究了网纹甜瓜果实喷钙对果肉硬度的影响：1)网纹甜瓜果实采后软化，成熟期喷钙延长果实软化时间。‘安得苏’网纹甜瓜果实在遮荫或厌氧条件下生长。1)厌氧氮素胁迫促进了‘安得苏’甜瓜果肉的乙醇发酵。然而，细胞壁物质如糖醛酸和细胞壁中性糖的浓度并没有因厌氧氮胁迫而降低。

1. Effect of shading on the occurrence of water-soaked symptom in netted melon fruits were studied.1) Degradation of pectic substances were more apparent in 'Andesu' than in 'Luster'.2) Shading induced a rapid softening in the flesh of both cultivars. However, there was no apparent difference between cultivars in total uronic acids.3) Shading induced a rapid degradation of cell wall neutral sugars, especially galactose, glucose, and xylose. These results suggest that the early softening in netted melon fruits under shading conditions might be due to the reduction in connections of cell wall components between pectin and pectin and /or hemicellulose and pectin.2. Changes in flesh firmness as influenced by calcium spray in netted muskmelon fruit were studied.1) The softening of netted melon fruit during storage after the harvest prolonged by calcium treatment during the fruit maturation.3. 'Andesu' netted melon fruits were grown under shaded or anaerobic condition.1) Ethanolic fermentation in 'Andesu' melon flesh was increased by anaerobic nitrogen stress. The concentration of cell wall substances like uronic acids and cell wall neutral sugars, however, did not decrease by anaerobic nitrogen stress.