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ARS Home » Plains Area » El Reno, Oklahoma » Oklahoma and Central Plains Agricultural Research Center » Peanut and Small Grains Research Unit » Research » Publications at this Location » Publication #408125
Research Project: Management Strategies for Invasive Aphid Pests of Cereals

Location: Peanut and Small Grains Research Unit

Title: Physiological and morphological responses of susceptible and resistant barleys to bird cherry-oat aphid feeding

Author
item HAYASHIDA, RAFAEL - Oklahoma State University
item Armstrong, John
item HOBACK, WYATT - Oklahoma State University
item Mornhinweg, Dolores - Do

Submitted to: American Journal of Plant Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/2023
Publication Date: 10/11/2023
Citation: Hayashida, R., Armstrong, J.S., Hoback, W., Mornhinweg, D.W. 2023. Physiological and morphological responses of susceptible and resistant barleys to bird cherry-oat aphid feeding. American Journal of Plant Sciences. 14(10):1115-1129. https://doi.org/10.4236/ajps.2023.1410076.
DOI: https://doi.org/10.4236/ajps.2023.1410076

Interpretive Summary: We measured the Physiological and morphological response of bird cherry-oat aphid feeding on resistant and susceptible barleys infested with a range of BCOA numbers over a four-week period. Chlorophyll content, photosynthetic rate, stomatal conductance, plant height and weight were greater for the resistant cultivar CI-1969 as opposed to the susceptible “Morex”. The research confirms the theory that BCOA damage through feeding is almost a straight relationship with the amount of assimilate loss in relation to the number of infesting aphids. The BCOA does not have a virulent toxin within the saliva for example like the greenbug does. The greenbug toxin is known to be deadly to chlorophyl production, so the physiological and morphological losses caused from BCOA infesting and feeding on barley is a direct relationship with the amount of assimilate lost.

Technical Abstract: The bird cherry-oat aphid (Rhopalosiphum padi [Linnaeus, 1758]) is considered a key pest of cereal crops worldwide, causing direct damage through sap feeding and by acting as a vector for viral diseases. Managing aphids is challenging because of their biology and potential resistance to insecticides. Developing resistant barley genotypes is a sustainable strategy for managing BCOA. In this study we assessed responses of susceptible 'Morex' and resistant 'CI-1969' barley genotypes to different initial BCOA densities (0, 50, 100 or 200 aphids/plant). Physiological and morphological parameters were measured weekly for four weeks after infestation. Chlorophyll content, photosynthetic rate, stomatal conductance, plant height and weight were greater for the resistant cultivar at lower aphid abundances and up to three weeks after infestation. Carbon assimilation curves (A/Ci) of infested CI-1969 were similar to controls 15 days post infestation, differing from Morex. However, BCOA infestation of 50 aphid.plant-1 for two weeks negatively impacted the fitness of both genotypes. Initial resistance by CI-1969 to BCOA infestation can allow growers and natural enemies more time contributing to more effective and sustainable management of BCOA infestations.