Objective To identify the variations on volatile organic compounds (VOCs) in mango leaves due to infestation by Procontarinai robusta for future study to mitigate or control the disease caused by the midge.
Method The VOCs in healthy leaves from a mango tree were compared with those in the midge-infested leaves by using headspace solid-phase microextraction (SPME) combined with gas chromatography mass spectrometry (GC–MS).
Result The healthy leaves were found to contain 65 VOCs, while the diseased ones 66 VOCs. Between them, 45 were identical which included caryophyllene, α-cyanene, octadecene, decene, hydrocelene, β-Myrcene, and terpenes. In the diseased leaves, 31 terpenes contributed 51.41%, while 13 aromatic compounds made up 41.10%, of the total. Besides naphthalene and azulene compounds, methyl-4-(1-methylethylidene)-cyclohexene comprised 24.32%, α-cubebene 8.92%, 3-carene 2.23%, acetate 3-hexen-1-ol 2.23%, 4-carene 1.06%, limonene 1.04%, and α-caryophyllene 1.46%. The content of esters was much higher in the midge-infested leaves than that of the healthy counterparts, and the composition also differed from each other. Minute amounts of substances, such as octanol, lanthanol, spartanol, epichlorohydrin, long citronellol and coumarins, were detected in the healthy leaves but not in the infested samples. Whereas, aristoloene, farnesene and some special naphthalene and azulene aromatic compounds were found only in the midge-infested leaves.
Conclusion The VOCs in mango leaves mainly consist of aromatic components and terpenes, the composition and content of which were obviously changed after Procontarinairobusta damage.
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