ABSTRACT

Ethylene plays an important role in kiwifruit ripening. However, it is unclear whether there are differences in ethylene production in different parts of kiwifruit during postharvest ripening. Kiwifruit were treated with 0.5 μL L⁻¹ 1-MCP for 12 h at 20°C and stored at 20 ± 1°C. The results showed the firmness, soluble sugar, total soluble solids (TSS), and AcACS1 and AcETR2 gene expressions were the highest in the core, and starch, AcACO2, and AcACO3 gene expressions were the highest in the seedless pulp at harvest. Starch content and firmness decreased significantly, and soluble sugar content, TSS, AcACO2, and AcETR2 gene expressions increased significantly in all parts during postharvest ripening. On the other hand, 1-MCP can significantly inhibit these changes in the fruits during ripening. The respiration rate and AcACS1 gene expression increased first and then reduced in all parts and were suppressed by 1-MCP. Ethylene was detected in the core and seeded pulp at 3 and 9 d of storage, respectively, but not in the seedless pulp. Overall, the results suggested there are differences in softening, ethylene production, and related gene expression in different parts of kiwifruit at harvest and during postharvest ripening, and 1-MCP inhibited softening and ethylene production of kiwifruit during postharvest ripening.

摘要

乙烯在猕猴桃的成熟过程中起着重要作用。然而，目前尚不清楚猕猴桃采后成熟过程中不同部位的乙烯产量是否存在差异。猕猴桃在 20°C 下用 0.5 μL ^-1 1-MCP 处理 12 小时，并在 20 ± 1°C 下储存。结果表明，果实硬度、可溶性糖、总可溶性固形物（TSS）、AcACS1和AcETR2基因在核心中的表达量最高，淀粉、AcACO2和AcACO3基因在收获时的无核果肉中表达量最高。淀粉含量和硬度显着下降，可溶性糖含量、TSS、AcACO2和AcETR2在采后成熟过程中，所有部位的基因表达均显着增加。另一方面，1-MCP 可以显着抑制果实成熟过程中的这些变化。呼吸速率和AcACS1基因表达在各部位均先升高后降低，并被1-MCP抑制。分别在储存 3 天和 9 天时在核心和有籽果肉中检测到乙烯，但在无籽果肉中未检测到乙烯。综上所述，结果表明，猕猴桃采收期和采后成熟期不同部位的软化、乙烯产量和相关基因表达存在差异，1-MCP抑制猕猴桃采后成熟期的软化和乙烯产生。