Barley yellow dwarf virus

Barley yellow dwarf virus

Background

R. padi adults and nymphsThe bird cherry-oat aphid, Rhopalosiphum padi, is one of the most economically important insect pests of wheat, and is the main vector of barley yellow dwarf virus (BYDV) which causes a disease that can reduce cereal grain quality and yield by over 70%. This virus is exclusively transmitted by aphids during feeding.

In order to address knowledge gaps on aphid-plant-pathogen interactions under elevated CO2 (eCO2), the research team are conducting a series of chamber and FACE experiments. The study aims to improve understanding of the changes in disease incidence, spread and its impacts for wheat production under future climate conditions. This project continues the work conducted in a completed AGFACE study on BYDV and crown rot.

Project outline

Chamber experiments are being conducted to understand the effects of eCO2 on aphid biology, BYDV infection and plant nitrogen concentration. Aphid fecundity, feeding behaviour and the implications for virus transmission are being measured.

Field experiments measuring the impact of eCO2 on yield and quality on non-infected and BYDV infected wheat are validating the chamber experiments and extending the study to new cultivars. 

Results

BYDV and its aphid vector are expected to increase in severity under future climates with increased CO2 and temperatures:

  • BYDV infection increases nitrogen concentration in plants under eCO2, improving its suitability for the aphid pest
  • Under eCO2, BYDV infected plants do not lose as much nitrogen from leaves as non-infected plants, making these plants more attractive to the aphids, increasing the chances of virus transmission to non-infected plants
  • The amount of virus in the plants was greater in eCO2 than under ambient CO2, increasing yield losses in infected plants. This also suggests improved virus acquisition and transmission leading to greater virus spread under future climate.

Next steps

Data from the 2015 field study are currently being analysed.