The Effects of Fruit Maturity and 1-Methylcyclopropene (1-MCP) Treatment on α-farnesene Metabolism in Scald Resistant and Susceptible Cultivars of Apple Fruit

Background: it was found that, climatic conditions and fruit ripeness are important factor forthe occurrence and intensity of superficial scald. 1-mcp is an inhibitor of ethylene action inplants and inhibits many ripening related processes along with the production of ethylene andvolatiles.objective: apples are often held for several months at low temperature either in air (ra) or incontrolled atmosphere (ca) storage, therefore they are prone to the occurrence of a largenumber of physiological disorders. in this work an investigation was made in order to determinethe effect of 1-methylcyclopropene (1.0 μl l-1) treatment on superficial scald development and α-farnesene metabolism on scald-resistant ‘golden delicious’ and scald-susceptible ‘imperialdelicious ' apples.methods: fruits harvested on two dates and stored 24 weeks in refrigerated air storage (ra) at 0.5-1 °c.peel tissue samples were taken at harvest after 6, 12 and 24 weeks. a reversed-phase high-performanceliquid chromatographic procedure with uv detection at 232 nm and 269 nm has been used for thedetermination of α-farnesene and ctols contents.results: scald symptoms were restricted to untreated control fruit of both harvests of imperialas during storage period increased to 65 and 45%, respectively for the first and second harvestcompared with no scald symptoms in those in golden delicious. at 1.0 μll-1, 1-mcp completely eliminated superficial scald during storage period in imperial apples. largeincreases in peel tissue content of α-farnesene observed in untreated fruit of both harvest dates ingolden delicious and imperial cultivars. 1-mcp strongly decreased α-farnesene and conjugatedtrienols accumulation in treated fruit peel tissues at both maturity stages of two cultivars duringstorage. the results confirm the proposed role of ctols in scald induction and indicate that α-farnesene production is strongly regulated by ethylene.conclusion: in general, we conclude that only α-farnesene synthesis and its oxidation products(ctols) levels in peel tissue could not be involved to the inherent nature of scald susceptibility orresistance in two cultivars tested.