Abstract: Volatiles are an important aspect of the flavor quality of tomato fruits. However, whether volatiles in tomato fruits respond to the regulation of exogenous methyl jasmonate (MeJA) remains unclear. In this study, four concentrations of MeJA (1, 10, 100 and 200 μmol/L) were sprayed on ‘Chaoyan 298’ tomatoes before harvest, and an equal volume of ultrapure water was used as the control. Ripe fruits were harvested and analyzed for the composition and content of volatile compounds by headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). Meanwhile, the optimal concentration of MeJA for improving the flavor quality of tomatoes was determined by multivariate statistical analysis. The results showed that a total of 71 volatile components were detected in the 5 groups, including 23 aldehydes, 17 alcohols, 8 ketones, 7 esters, 6 hydrocarbons and 10 other substances. Compared with the control group, exogenous application of MeJA increased the number and total amount of volatile compounds in tomato fruits, which increased first and then decreased with the increase in MeJA concentration, reaching the maximum value at 100 μmol/L MeJA concentration. Altogether 33 components were common to all groups, with the most abundant one being (Z)-3-hexen-1-ol. A total of 13 characteristic aroma components were identified in all tomato fruits, which mainly contributed to green, fruity and flowery notes. Overall, our results provide theoretical support that exogenous MeJA can improve that flavor quality of tomato fruits, which are conducive to further exploring the regulation mechanism of volatile compound biosynthesis in tomato fruits.

Key words: tomato fruits; methyl jasmonate; headspace-solid phase microextraction-gas chromatography-mass spectrometry; volatile compounds; aldehydes; principal component analysis