Aroma and sensory quality of honeydew melon fruits (Cucumis melo L. subsp. melo var. inodorus H. Jacq.) in relation to different rootstocks

The research evaluates the influence of some selected rootstocks on the C. melo L. subsp. melo var. inodorus H. Jacq. (honeydew melon) cv. Incas fruit quality. Four Cucurbita maxima×Cucurbita moschata hybrids (namely Polifemo, AS10, RS841 and P360) and two genotypes of melon (Energia and Sting), selected for their disease resistance, were tested as rootstocks under greenhouse conditions. Physical properties, chemical data, volatile constituents and sensory descriptors were used for quality determination. All the used rootstocks exhibited a good affinity with the scion, with Polifemo and RS841 showing a productivity higher (about 15%) and a significant increase in fruit weight (about 10%) than the control. As regards the titratable acidity (TA) and the total soluble solids (TSS), similar values resulted among the samples, except for the higher levels of TA in Incas/AS10 and Incas/Sting and the higher of TSS in Incas/AS10. As regards the volatile compounds, the content of key aroma, aldehydes containing a straight nine-carbon chain, such (Z)-3-nonen-1-ol and (Z)-6-nonenal resulted lower in most of the grafted samples (20–60% and 8–45% less than the control, respectively). In relation to the key aroma compounds, the melons grafted on Energia, RS841, P360 and Polifemo rootstocks resulted more similar to the control. 14 sensory descriptors were defined for the appearance, aroma, taste, texture traits, flavor and overall. Energia grafting combination presented the sensory descriptor intensities more close to the ungrafted Incas samples. In conclusion, the quality of the grafted inodorus melon fruits was modified in a different way according to the grafting combinations; RS841 and Polifemo can be successfully used as rootstocks for the inodorus melon since they increased disease resistance and productivity without determining relevant changes on fruity quality.