| Title: | Chemical ecology of Himalayan eggplant variety's antixenosis: identification of geraniol as an oviposition deterrent against the eggplant shoot and fruit borer |
| Author(s): | Ghosh R; Metze D; Sant S; Shaikh M; Deshpande A; Firake DM; Pandit S; |
| Address: | "Agricultural Biotechnology and Chemical Ecology (ABCE) Lab, Indian Institute of Science Education and Research, Pune, Maharashtra, 411008, India. Division of Crop Protection, ICAR Research Complex for NEH Region, Umiam, Meghalaya, 793103, India. ICAR-Directorate of Floricultural Research, Pune, Maharashtra, 411036, India" |
| ISSN/ISBN: | 1469-8137 (Electronic) 0028-646X (Linking) |
| Abstract: | "Eggplant (Solanum melongena) suffers severe losses due to a multi-insecticide-resistant lepidopteran pest, shoot and fruit borer (SFB, Leucinodes orbonalis). Heavy and combinatorial application of pesticides for SFB control renders eggplant risky for human consumption. We observed that gravid SFB females do not oviposit on Himalayan eggplant variety RC-RL-22 (RL22). We hypothesized that RL22 contained an antixenosis factor. Females' behavior indicated that the RL22 cue they perceived was olfactory. To identify it, leaf volatile blends of seven eggplant varieties were profiled using solid phase microextraction and gas chromatography mass spectrometry. Seven RL22-specific compounds were detected in the plant headspace. In choice assays, oviposition deterrence efficacies of these candidate compounds were independently tested by their foliar application on SFB-susceptible varieties. Complementation of geraniol, which was exclusively found in RL22, reduced oviposition (> 90%). To validate geraniol's role in RL22's SFB-deterrence, we characterized RL22's geraniol synthase and silenced its gene in planta, using virus-induced gene silencing. Geraniol biosynthesis suppression rendered RL22 SFB-susceptible; foliar geraniol application on the geraniol synthase-silenced plants restored oviposition deterrence. We infer that geraniol is RL22's SFB oviposition deterrent. The use of natural compounds like geraniol, which influence the chemical ecology of oviposition, can reduce the load of hazardous synthetic larvicides" |
| Keywords: | Leucinodes orbonalis Solanum melongena antixenosis chemical ecology host selection oviposition deterrence pest management volatile organic compounds (VOCs); |
| Notes: | "PublisherGhosh, Rituparna Metze, Dennis Sant, Surhud Shaikh, Maroof Deshpande, Ashish Firake, Dnyaneshwar M Pandit, Sagar eng Council of Scientific and Industrial Research, India/ 1144/Indian Institute of Science Education and Research Pune/ Ministry of Human Resource Development, India/ NAMASTE+program/DAAD and the German Ministry of Education and Research/ Science and Engineering Research Board, India/ England 2023/03/16 New Phytol. 2023 Nov; 240(3):1259-1274. doi: 10.1111/nph.18877. Epub 2023 Mar 30" |
