Fermentative metabolism and organic acid concentrations in fruit of selected strawberry cultivars with different tolerances to carbon dioxide

Effects of 20 kPa CO2 treatments on concentrations of fermentation products , organic acids, and activities of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH), were measured in fruit of selected strawberry cultiva rs (Fragaria xananassa Duch. 'Annapolis', 'Cavendish', 'Honeoye', 'Kent', ' Jewell', 'Lateglow',and 'NorthEast'). Acetaldehyde, ethanol, and ethyl acet ate concentrations accumulated in CO2-treated fruit of 'Honeoye' and 'Kent' , but not in 'Cavendish' or 'Annapolis'. The former two cultivars were clas sified as intolerant to high CO2 and the latter two as tolerant to high CO, . Activities of PDC and ADH were higher in CO2-treated than in air-treated fruit of the tolerant cultivars but not in the intolerant cultivars. Succin ate accumulated in fruit of all cultivars, but concentrations were higher i n the tolerant than in the intolerant cultivars. Results are discussed in r elation to tolerance of fruit to CO2.