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

首先，研究了果肉质外体和共体溶液的分离方法。结果发现，利用离心机是可行的。将这种方法应用于苹果果实，以阐明水核发育的机理。‘富士’苹果在最佳采收期前30天出现水核症状，并随果实成熟而延长。质外体溶液中蔗糖、果糖和葡萄糖的浓度在整个试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。在共生体溶液中，糖浓度变化很小。‘Yoko’和‘Orin’苹果没有出现水核。在这些品种中，质外体中的山梨醇浓度也随着果实的成熟而增加，但‘洋子’和‘奥林’苹果在最佳采收期的山梨醇含量分别是‘富士’苹果的1/4和1/5。其次，剥离周围环剥处理的效果是…研究了富士苹果果实水核发育和糖分积累的规律。因此，环剥处理抑制了成熟过程中水核的发生。在对照果实中，随着果实的成熟，山梨醇含量显著增加，尤其是在质外体溶液中。处理果实与对照果实相比变化不显著，且含量较低。这些结果表明，山梨醇在质外体中的积累参与了苹果果实水核的发育。最后，将质外体和共体溶液分离的方法应用于日本柿果实，以阐明单宁的定位和果实脱涩的机理。因此，质外体溶液中的单宁浓度高于共体溶液中的单宁浓度。此外，胞质外体溶液中单宁与乙醛的结合被认为与日本柿果实在CO_2处理下的快速失稳有关。较少

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