Could foliar applications of methyl jasmonate and methyl jasmonate+urea improve must grape aroma composition?

Abstract

Grape aromas are formed by a great number of volatile compounds. Methyl jasmonate (MeJ) and urea (Ur) foliar applications have been studied to improve grape quality, but their combined application has never been studied. In both seasons, MeJ application enhanced terpenoids and C6 compounds synthesis, whereas decreased alcohols content. Moreover, MeJ + Ur treatment reduced benzenoids and alcohols and did not affect C13 -norisoprenoids content. However, there was no clear effect of these treatments on the rest of volatile compounds. Multifactorial analysis showed a season effect on all volatile compounds, except terpenoids. Discriminant showed a good separation among samples under treatment criterion. The great effect of MeJ treatment on terpenoids was probably due to this elicitor influences their biosynthesis. Season has a strong influence on grapes aromatic composition since affected to all volatile compounds families but terpenoids. MeJ foliar application enhanced terpenoids, C13 -norisoprenoids and C6 compounds synthesis, whereas decreased alcohols content; however, MeJ + Ur foliar treatment did not affect C13 -norisoprenoids and C6 compounds, and decreased benzenoids and alcohols grape compounds. Therefore, no synergistic effect was observed between Ur and MeJ on grape volatile compounds biosynthesis. Foliar application of MeJ seems to be sufficient to improve the aromatic quality of grapes. This article is protected by copyright. All rights reserved.