Seed inoculation with beneficial rhizobacteria affects European corn borer (Lepidoptera: Pyralidae) oviposition on maize plants. Issue 1 (29th September 2017)

• Record Type: Journal Article
• Authors: Disi, Joseph Onwusemu; Zebelo, Simon; Kloepper, Joseph W.; Fadamiro, Henry
• Is Part Of: Entomological science. Volume 21:Issue 1(2018)
• Page Start: 48
• Page End: 58
• Publication Date: 2017-09-29
• Subjects: Bacillus spp -- Ostrinia nubilalis -- plant‐insect interactions -- soil health -- volatile organic compounds; Insects -- Periodicals; Entomology -- Periodicals; 595.705
• DOI: 10.1111/ens.12280
• Languages: English
• ISSNs: 1343-8786

Abstract

Abstract: Larvae of Ostrinia nubilalis (Hübner) cause significant damage to maize ears and reduce market value of fresh sweet corn. Females rely on volatile cues to locate and oviposit preferentially on maize plants. In addition, oviposition behavior of females is influenced by soil management practices as they usually lay more eggs on maize plants grown on conventional soil than on organic soils that harbor rich microbial diversity. Since some plant growth‐promoting rhizobacteria (PGPR) are known to mediate plant health via suppression of soil pathogens and enhanced uptake of nutrients; we hypothesized that inoculation of maize seeds with PGPR will alter emission of maize volatile and reduce the attractiveness of plants to ovipositing O. nubilalis . Plants treated with the single PGPR strain Bacillus pumilus INR‐7, two PGPR mixtures (Blend‐8 or Blend‐9) or untreated plants were presented to O. nubilalis females in oviposition choice bioassays. Headspace volatile organic compounds (VOCs) from the plants were analyzed by gas chromatography–mass spectrometry (GC–MS). Ostrinia nubilalis laid significantly fewer eggs on PGPR‐treated plants compared to untreated plants. In two‐choice oviposition experiments, significantly higher numbers of eggs were laid on untreated plants compared to PGPR‐treated plants. PGPR‐treated plants emitted fewer VOCs than untreated plants which, in part, explains the relatively fewer eggs on PGPR‐treated plants. These results indicate that selected PGPR treatments can alter maize plant volatiles with important ramifications for plant‐insect interactions. The implication of this finding is discussed in the context of integrated management of soil health to improve crop resistance to biotic stressors. Abstract : Ostrinia nubilalis females differentiated between maize plants treated with plant growth‐promoting rhizobacteria (PGPR) and untreated plants, by laying fewer eggs on PGPR‐treated plants. Fewer volatile organic compounds (VOCs) were detected among PGPR‐treated plants compared to control plants. Emission of smaller amounts of VOCs is likely a contributing factor to the relatively smaller numbers of eggs laid by O. nubilalis on PGPR‐treated plants.