Chemical Diversity between Three Graminoid Plants Found in Western Kenya Analyzed by Headspace Solid-Phase Microextraction Gas Chromatography–Mass Spectrometry (HS-SPME-GC-MS)

Linus Svenberg,Åsa Emmer

doi:10.3390/plants10112423

Abstract

In recent work, it was shown that the graminoid plants Cynodon dactylon (Poaceae), Cyperus exaltatus (Cyperaceae), and Panicum repens (Poaceae) have an ovipositional effect on the malaria vector Anopheles gambiae in olfactometric bioassays. In order to get a view of the diversity of semiochemicals present in the environment of the vector during olfactometric trials, in the present work, the volatile profiles of these graminoid plants were analyzed using headspace solid-phase microextraction (HS-SPME) together with gas chromatography–mass spectrometry (GC-MS). In addition, one-way ANOVA comparison of compounds detected in two or more headspace samples are presented in order to provide a basis for comparison of compounds that could constitute a starting point for novel blends of volatile organic compounds to be tested as oviposition attractants.

Highlights

The study of the influence of volatile compounds and their behavioral effects on insects is an important aspect of chemical ecology
Chemical Composition of Headspace Samples from C. dactylon, C. exaltatus, and P. repens In Table 1, the 46 compounds that were identified in the roots and/or the shoots of the three different graminoid plants are listed
It was shown that out of the 46 detected compounds, 26 were unique to C. exaltatus, 6 were unique to C. dactylon, and 2 were unique to P. repens, with 12 compounds overlapping in combinations between the studied plants

Summary

Introduction

The study of the influence of volatile compounds and their behavioral effects on insects is an important aspect of chemical ecology. One goal is to decrease the spread of diseases associated with certain species of insects An example of such a severe problem is the spread of malaria in sub-Saharan Africa, which has declined [1] when compared to the goals set by the World Health Organization (WHO) in their Global Technical Strategy for Malaria (GTS) report from 2016 [2]. Long-lasting insecticide nets (LLINs) and indoor residual spray (IRS) are the most commonly employed techniques to minimize the infection rate of malaria. These methods are limited to indoor use, and it has been shown that the effectiveness has subsided due to a decrease in usage [1]. The challenge in the development of these novel outdoor-focused control techniques is the identification of volatile organic compounds (VOCs) that could be used to influence the malaria vectors’ choice of egg-laying site

Methods

Results

Conclusion