Metabolomics of common bean (Phaseolus vulgaris L.) antixenosis to the Mexican weevil (Zabrotes subfasciatus Boh.)

Abstract

Zabrotes subfasciatus (Boheman) is one of the main pests of storage beans, affecting common bean (Phaseolus vulgaris L.) in tropical world regions. The aim of this study was to evaluate antixenosis of two P. vulgaris genotypes to Z. subfasciatus and the emission of volatile compounds from seeds of these genotypes. Antixenosis in adults and oviposition was evaluated using the obligate antibiosis test, on ‘G11051’ and ‘ICA Pijao’ genotypes of common bean to Z. subfasciatus. The volatile compounds of their seeds related to antixenosis were also evaluated. The number of adult insects away from seeds, the percentage of eggs in seeds and the container and the number of total eggs were counted. The presence of volatile compounds was determined by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS). Genotype ‘G11051’ showed higher adult antixenosis (80% non-preference) and antixenosis by oviposition on their seeds than ‘ICA Pijao’ genotype which showed only 11% repellency. Significant statistical differences were found in the volatile compounds detected. ‘G11051’ showed 65 compounds and 22 specific to this genotype, while in ‘ICA Pijao’, 53 compounds were detected, eight of which were specific to this genotype. Of these, dimethyl disulfide, limonene, (E)-2-hexenal and hexanal showed known antixenotic activity.