Morphological and quality characterization of grape berry and rachis in response to postharvest 1-methylcyclopropene and elevated oxygen and carbon dioxide atmospheres

This research studied the morphological characterization and quality attributes of ‘Kyoho’ and ‘Yongyou NO.1’ (Vitis vinifera L. × Vitis labrusca L.) grape berry and rachis in response to postharvest treatment with 1-methylcyclopropene (1-MCP) alone or in combination with elevated 80% O 2 (H-O 2 ) / 20% CO 2 (H-CO 2 ). Results indicated that the integrated application of exogenous 1-MCP alone and combined with H-O 2 /H-CO 2 significantly prevented the rachis browning and chlorophyll degradation, maintained the cellular microstructure integrity and promoted esters and terpenes synthesis. Additionally, the transcriptional expression of genes involved in ethylene biosynthesis was sharply downregulated by 1-MCP treatment in both cultivar rachis and berries. And genes expression related to softening was also downregulated by 1-MCP alone and plus elevated O 2 /CO 2 atmospheres treatment. Particularly, the combinatorial treatment of 1-MCP and H-O 2 effectively impeded berry abscission and alcohols accumulation; whereas 1-MCP with H-CO 2 treatment maintained the membrane permeability in berries. Nevertheless, 1-MCP alone or in combination with elevated atmospheres did not significantly affect total soluble solids and titratable acidity and did not harm sensory quality in both ‘Kyoho’ and ‘Yongyou NO.1’ cultivars after 32 days of storage.