不同采收成熟度油桃贮藏效果及果肉细胞超微结构观察

以秦光2号油桃果实为材料,在0℃贮藏条件下研究了5个采收成熟度果实的贮藏效果及果肉细胞超微结构的变化。结果表明,(1)处理Ⅳ成熟度果实贮藏40d后能保持相对较高的硬度和可溶性固形物,货架期品质好,好果率高,贮藏效果好,为最佳采收成熟度。(2)采收当天的处理Ⅰ、Ⅱ、Ⅲ成熟度的果实,果肉细胞的超微结构无明显差异;处理Ⅳ成熟度果实,叶绿体开始变形,细胞外壁开始有少许微纤丝松懈;处理Ⅴ成熟度果实,细胞壁中胶层开始溶解,电子密度降低,出现质壁分离和液泡破损现象。(3)贮藏50d后,不同成熟度的果实,果肉细胞的超微结构都发生明显变化,显示出果肉细胞间隙增大,细胞内含物减少,出现细胞空腔化;细胞壁中胶层降解,细胞壁弯曲或皱缩,质壁分离严重;细胞器变形或降解等现象。

Effect of harvest maturity on storage quality of nectarine and flesh cell ultrastructure

The fruit of nectarine cultivar Qinguang 2 were used to study the effects of 5 harvest maturities on storage quality and the ultrastructure changes of flesh cells during cold storage. It was showed that (1)at maturity grade Ⅳ fruit maintained their higher firmness and soluble solid content after stored for 40 d and had high ratio of good fruit and good quality at the shelf life stage,so that was the best harvest maturity.(2)On the first harvest day,flesh cell ultrastructure of fruits collected at maturity grade of Ⅰ, Ⅱ and Ⅲ did not have a significant difference; Fruits collected at maturity grade of Ⅳ presented the structure of chloroplast deformable and out of cell wall micro-fibril loosed; Fruit at maturity grade of Ⅴ presented mesogloea became dissolved,density of electron decreased,the plasmolysis and tonoplast membrane breakeage generally appeared.(3) After storage for 50 d, the ultrastructure flesh cells of all maturity grade changed significantly,it showed that gap junctional intercellular enlarged,cell contents decreased,cell empty cavity,cell wall mesogloea dissolved,cell wall crinkle bended,the phenomenon of plasmolysis was seriously and cell organelle deformed or degraded.