Studies on postharvest physiology of fruit by using the method for separation of apoplastic and syplastic solution

首先，研究了果肉外质体溶液和共质体溶液的分离方法。结果，人们发现使用离心机是可能的。将该方法应用于苹果果实，阐明了水核发育的机理。富士苹果在最佳采收期前30天出现水核症状，并随着果实成熟而延长。蔗糖、果糖和葡萄糖的浓度在整个实验期间没有显著变化，而山梨醇的浓度随着果实的成熟而显著增加。在共塑溶液中，糖浓度变化很小。在“yoko”和“orin”苹果中，没有出现水核。在这些品种中，随着果实的成熟，外体液中山梨醇的浓度也有所增加，但“阳子”和“奥林”苹果在最佳采收期的含量分别是“富士”苹果的四分之一和五分之一。其次，研究了果实剥落前后的包皮处理对富士苹果水核发育和糖积累的影响。结果表明，环剥处理抑制了成熟过程中水核的发生。在对照果实中，随着果实成熟，山梨醇浓度显著增加，尤其是在外质体溶液中。在处理过的水果中，它们没有显著变化，与对照水果相比，它们的水平很低。这些结果表明，山梨糖醇在外质体中的积累参与了苹果果实水核的发育。最后，将外质体溶液和共质体溶液的分离方法应用于柿子中，以明确单宁的定位和果实脱水的机制。结果表明，外质体溶液中的单宁浓度高于共质体溶液。另外，CO_2处理后柿子果实中单宁与乙醛的结合迅速积累，可能与CO_2处理后柿子果实脱水迅速有关。少

First, the method for separation of apoplastic and symplastic solutions of fruit flesh was investigated. As a result, it was found to be possible by using a centrifuge.This method applied to apple fruit to clarify the mechanism of watercore development. In‘Fuji' apples, the symptom of watercore was observed 30 days before optimum harvest date, and extended as fruit ripened. Concentrations of sucrose, fructose and glucose in apoplastic solution did not significantly change throughout an experimental period, while sorbitol concentration markedly increased as fruit ripened. In symplastic solution, changes in sugar concentrations were small. In‘Yoko' and‘Orin' apples, watercore did not occurred. In these cultivars, sorbitol concentration in apoplastic solution also increased as fruit ripened, but the levels at optimum harvest date in‘Yoko' and‘Orin' apples were one forth and one fifth of that of‘Fuji' apples, respectively.Secondly, the effect of girdling treatment around the abscission lay … More er of fruit on watercore development and sugar accumulation in‘Fuji' apples was investigated. Consequently, girdling treatment suppressed the occurrence of watercore during ripening. In control fruit, sorbitol concentrations markedly increased especially in apoplastic solution as fruit ripened. In treated fruit, they did not significantly change and were low levels compared with those of control fruit. These results indicated that the accumulation of sorbitol in apoplast was involved in the development of watercore in apple fruit.Finally, the method for separation of apoplastic and symplastic solutions applied to Japanese persimmon fruit to clarify the localization of tannin and the mechanism of deastringency of fruit. Thus, tannin concentration was higher in apoplastic solution than that in symplastic solution. In addition, the bonding of tannin in apoplastic solution and acetaldehyde, which rapidly accumulated after treatment, was thought to be related to rapid destringency by CO_2 treatment in Japanese persimmon fruit. Less