Development of portable E-nose system for early diagnosis of insect-stressed tomato plants

摘要

A portable electronic nose (E-nose) system equipped with a sensitive sensor array was successfully developed to detect insect-stressed tomato plants, which were infested by aphids and whiteflies for 2 to 3 days, by taking advantages of their unique volatile organic compounds (VOCs) profiles. With showing fast sensor responses, an accurate diagnosis of aphids-stressed, whiteflies-stressed tomato plants from healthy groups were verified with PCA results accounting for 86% classification, which confirmed the promising capability of E-nose system providing a fast and reliable detection of infested tomato plants at early stage. For comparison, the changes of VOCs profiles were quantitatively determined by gas chromatography-mass spectrometry (GC-MS), with results showing that a group of new VOCs biomarkers (methyl salicylate and several terpenes) played info-chemical roles in the tomato-aphids interaction and tomato-whiteflies interaction, respectively. Moreover, the variation of the concentration of VOCs compounds explained the sensors behaviors during E-nose test, which confirmed the reliability and accuracy of the developed E-nose system. The satisfactory diagnosis among unstressed and insect stressed tomato plants as well as samples between, demonstrated the E-nose system had promising potential for a smart insect control at early stages in greenhouse.