Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/4/2008
Publication Date: 4/4/2008
Citation: Olson, D.M., Davis, R.F., Wakcers, F.L., Rains, G.C., Potter, T.L. 2008. Plant-herbivore-carnivore interactions in cotton, Gossypium hirsutum linking below and above ground [abstract]. Entomological Society of Georgia Meeting, April 2-4, 2008, Cordele, GA. Interpretive Summary:
Technical Abstract: Most studies on plant-herbivore interactions focus on either root or shoot herbivory in isolation, but above- and belowground herbivores may interact on a shared host plant. Cotton (Gossypium spp.) produces a variety of terpenoid aldehydes that exhibit toxicity to a wide range of herbivores and pathogens. Cotton plants also can emit herbivore-induced volatile compounds systemically on all tissues above the site of damage, and as these volatile compounds attract natural enemy species of the herbivore, they are thought to represent an indirect plant defense. Our study evaluated terpenoid production by cotton plants in response to foliage feeding (Heliocoverpa zea), root feeding (Meloidogyne incognita) or their combination as well as the attraction of the parasitic wasp Microplitis croceipes to those plants. We also evaluated whether foliage or root feeding affected foliar nitrogen levels in cotton. After 48 hours of leaf feeding and 5 weeks of root feeding, systemic induction of volatile terpenoids (known to attract parasitoids such as M. croceipes) occurred with herbivore damage to leaves regardless of root herbivory. In addition, M. croceipes were attracted only to plants with leaf damage. In contrast to previous studies in cotton, terpenoid aldehydes were not induced in leaf and root tissue following foliage or root herbivory, or their combination. We conclude that root feeding by M. incognita has little influence on direct or indirect defenses of G. hirsutum against insect herbivory.