Influence of different rootstocks on quality and volatile constituents of cantaloupe and honeydew melons (Cucumis melo. L) grown in high tunnels

Abstract

Two rootstock crosses of sweet melon and watermelon (Cucurbita moschata × Cucurbita maxima hybrids), 'Kickstart' and 'Carnivor', grafted onto four melon cultivars (cantaloups; 'Majestic', 'Hunter', 'Honeygoal' and 'Honeyval') were evaluated for quality, phytonutrient composition and volatile compounds in the 2020 and 2021 growing season at two harvests. Grafted fruits showed higher SSC/TA ratio, and antioxidant scavenging activity. Grafted 'Majestic/Carnivor' and 'Honeyval/ Carnivor' melons significantly increased the ascorbic acid content than the controls. 'Majestic/Carnivor' melons showed the highest β- carotene and lutein than the controls. PLS-DA score plots discriminated the grafted cantaloupes and honeydew melons from controls based on the concentration of volatile compounds. Hexyl acetate and hexadecane respectively discriminated the grafted cantaloups and honeydew melons from ungrafted fruits. 'Carnivor' rootstocks showed higher expression of volatiles in the grafted cantaloupes and honeydew melons in the heat map. Panellists preferred Majestic/Carnivor' and 'Honeyval/ Carnivor' melons.

Keywords: Antioxidant activity; Chemometric approach; Cucumis melo; Grafting; Volatile compounds.