Physiological responses of wheat and barley to Russian wheat aphid, Diuraphis noxia (Mordvilko) and bird cherry-oat aphid, Rhopalosiphum padi (L.) (Hemiptera: Aphididae)

• Published in: Arthropod-plant interactions 2008-12, Vol.2 (4), p.227-235
• Main Authors: Franzen, Lisa D., Gutsche, Andrea R., Heng-Moss, Tiffany M., Higley, Leon G., Macedo, Tulio B.
• Format: Article
• Language: English
• Subjects: Agronomy; Aphididae; Barley; Behavioral Sciences; Biomedical and Life Sciences; Chlorophyll; Diuraphis noxia; Ecology; Electron transport; Entomology; Exchanging; Feeding; Fluorescence; Hemiptera; Hordeum vulgare; Host plants; Impact damage; Infestation; Insects; Invertebrates; Life Sciences; Original Paper; Parameters; Pests; Photochemicals; Photosynthesis; Physiological responses; Physiology; Plant Pathology; Plant physiology; Plant Sciences; Rhopalosiphum padi; Species; Transport rate; Triticum aestivum; Wheat; Xanthophylls
• ISSN: 1872-8855; 1872-8847
• DOI: 10.1007/s11829-008-9048-1

Although aphids are among the most injurious of all agronomic insect pests, much remains unknown about how their feeding alters plant physiology. Two experiments were conducted to examine the physiological responses of wheat, Triticum aestivum L. and barley, Hordeum   vulgare L. to injury by Diuraphis   noxia (Mordvilko) and Rhopalosiphum   padi (L.) (Hemiptera: Aphididae). Gas-exchange parameters, chlorophyll fluorescence, and chlorophyll content were examined at 3, 6, and 9 days post-infestation on control and aphid ( D.   noxia and R.   padi ) infested treatments. In general, chlorophyll content and chlorophyll fluorescence parameters (non-variable minimal fluorescence, maximal fluorescence, and variable fluorescence) were not significantly affected by either aphid species. Photochemical and non-photochemical quenching coefficients were significantly impacted by both aphid species, suggesting that aphid feeding may influence the photoprotective xanthophyll cycle altering the thylakoid membrane pH gradient. Feeding by both aphid species resulted in an increase in electron transport rate, but at different time periods. Wheat plants infested with D. noxia had accelerated declines in photosynthetic capacity when compared to R. padi -infested and control plants. These plants exhibited decreased values for A max , which was accompanied by decreased values for V cmax and J max Neither aphid species negatively affected the photosynthetic capacity of the barley plants until day 9. At this time, aphid-infested plants had decreased values for A max which was accompanied by decreased values in J max . Although R.   padi feeding does not typically result in visual damage symptoms as previously demonstrated, clearly this aphid does have an impact on the gas-exchange and chlorophyll fluorescence of its host plants.