SO₂ treatment is currently the preferred method for postharvest preservation of table grapes, while inappropriate amount of environmental SO₂ would render kinds of physiological damage, including tissues bleaching, flavor destroying and berry abscission. Our previous study has reported that 1.5% chitosan solution treatment could inhibit postharvest berry abscission of the ‘Kyoho’ table grapes, especially caused by excessive SO₂ treatment. However, the physiological mechanism of chitosan inhibiting SO₂-induced berry abscission still remains unclear. This study further focused on physiological changes of the abscission zone (AZ) between stalk and pedicle, including fruit detachment force (FDF), the microscopic structure, cell wall degrading enzymes and SO₂ permeation, during storage of the ‘Kyoho’ table grapes with different postharvest treatments. The results showed that the 1.5% chitosan treatment remarkably suppressed the decrease of FDF, and delayed the structural deterioration in AZ during storage. Meanwhile, this chitosan treatment also distinctly suppressed the increase of cell wall degrading enzymes activity and SO₂ permeation into AZ, which showed statistically linear relationship with abscission index. Those results contribute to elucidate the physiological mechanism of chitosan-inhibited berry abscission and develop new preservation technology with greater commercial value for postharvest table grapes in the future.

目前，SO ₂处理是用于鲜食葡萄收获后保存的首选方法，而适量的环境SO ₂会造成各种生理损害，包括组织漂白，破坏风味和浆果脱落。我们以前的研究报告说，使用1.5％的壳聚糖溶液处理可以抑制“ Kyoho”食用葡萄采后浆果的脱落，尤其是过度的SO ₂处理所致。然而，壳聚糖抑制SO ₂的生理机制引起的浆果脱落仍然不清楚。本研究进一步研究了在“ Kyoho”食用葡萄贮藏期间，茎与蒂之间的脱落区（AZ）的生理变化，包括果实脱离力（FDF），微观结构，细胞壁降解酶和SO ₂渗透。不同的采后处理。结果表明，1.5％的壳聚糖处理显着抑制了FDF的降低，并延迟了储藏期间AZ的结构恶化。同时，这种壳聚糖处理还明显抑制了细胞壁降解酶活性和SO ₂的增加。渗入AZ，与脱落指数在统计上呈线性关系。这些结果有助于阐明壳聚糖抑制浆果脱落的生理机制，并为将来的采后食用葡萄开发具有更高商业价值的新保鲜技术。