|Elevated CO2 increases wheat susceptibility to Barley yellow dwarf virus|
P. TREBICKI (1), N. Nancarrow (2), A. Freeman (3), N. Bosque-Pérez (4), A. Yen (2), G. Fitzgerald (5). (1) Department of Economic Development, Horsham, , Australia; (2) Department of Economic Development, Bundoora, Australia; (3) Department of Economic Development, Horsham, Australia; (4) University of Idaho, Moscow, ID, U.S.A.; (5) Department of Economic
Understanding how future climate conditions and increasing atmospheric carbon dioxide will shape agricultural production is essential in order to sustain or improve current crop production levels. Pests and diseases are major contributors to the reduction of crop yield and are responsible for raising input costs. <i>Barley yellow dwarf virus</i> (BYDV) can cause serious crop disease transmitted by many aphid species. This virus causes yellowing and stunting of plants and adversely affects the yield and quality of wheat, barley and oats as well as other economically important crops in Australia and worldwide.
In this study, we used Australian Grains Free Air CO<sub>2</sub> Enrichment (AGFACE) facility and plant growth chambers to understand the insect, plant and pathogen interactions. We exposed infected and uninfected wheat and the bird cherry-aphid (<i>Rhopalosiphum padi</i>), the main vector of BYDV, to ambient and eCO<sub>2</sub> (550ppm FACE, 650 ppm chambers) levels. We examined the severity of BYDV in plants, aphid biology in both virus free and BYDV infected plants, as well as plants and virus response under these two CO<sub>2</sub> scenarios.
Despite the positive effect of eCO<sub>2</sub> on yield and wheat growth, our study showed detrimental CO<sub>2</sub> effects on grain quality and BYDV severity. We found that BYDV titre significantly increased in the leaves of wheat plants grown under eCO<sub>2</sub> conditions, leading to a decrease in yield. We also found a decrease in aphid fecundity on uninfected plants; however, no changes in aphid reproduction were detected on BYDV infected plants. In addition, changes to wheat physiology mediated by eCO<sub>2</sub>, resulted in significantly extended aphid feeding activity on uninfected plants. Other experimental data from both the FACE facility and environmental growth chambers will be described and the results from these experiments presented