Reppelency to spider mite mediated by the gene mi and by the synergism between high foliar contents of acylsugar and zingiberene in tomato

Abstract

Tomato fruits (Solanum Lycopersicum) are intended for human consumption in its in natura or industrially processed form. However, the expansion of its cultivation area has favored the emergence of pests, such as spider mite (Tetranychus urticae), which significantly affects the production. The objective of this study was to quantify and evaluate the repellency of tomato lines to spider mite in function of the gene Mi and of the individual and synergistic effects of acylsugar and zingiberelene allelochemicals. The experiment consisted of a complete randomized design with four replications. For the bioassay, four fully expanded leaflets with similar size were removed from the upper third of the plants at pre-flowering phenological stage. The bioassay was carried out in a cold chamber, at 16±1°C, and 64 ± 4% RH. The gene Mi was not effective in conferring repellency to spider mite. On the other hand, zingiberene and acylsugar were efficient and equivalent regarding repellency to spider mite. When combined in tomato lines, zingiberene and acylsugar had synergistic effect, which increased repellency to spider mite.