Insect-vectored plant viruses constrain crop production worldwide and seriously affect several important Idaho crops. Managing insect vectors is an important component of virus disease management in potatoes, wheat, and peas in Idaho. The purpose of this study is to explore newly-discovered effects of volatiles from virus-infected plants on the aphid vectors of important viruses affecting these crops.
Potato Leafroll Virus-Related Objectives: 1) Identify the components causing GPA arrestment on PLRV-infected Russett Burbank, 2) Measure behavioral responses of two additional aphid clones to Russet Burbank and two other potato varieties, 3) Determine if volatiles produced and aphid responses change during the PLRV disease cycle, 4) Determine the responsiveness to PLRV-infected plants by alate aphids, 5) Determine the responsiveness of viruliferous aphids to PLRV-infected plants.
Barley Yellow Dwarf Virus-Related Objectives: 1) Confirm that BCOA is attracted to or arrested by BYDV-infected wheat plants, 2) Identify the changes in volatile profile associated with BYDV infection in wheat, 3) If indicated, identify the active components in the blend from infected wheat plants. Pea Enation Mosaic Virus-Related Objectives: 1) Determine the effect of PEMV-infection disease in pea plants on PA life history, 2) Examine the behavioral response of PA to PEMV-infected peas.
Bioassays using green peach aphid clones will be used to assess their response to plants infected with potato leafroll virus to determine how aphid developemental stage and virulence status, and how potato genotype and stage of the potato leafroll virus disease, influence aphid response to volatiles from the plants. Volatiles will be extracted from headspace and characterized by GC/MS. The specific cues affecting the aphids will be determined using behavioral and electrophysiological bioassays with pure compounds and fractions of the volatiles released from infected and healthy plants. Bioassays using a bird cherry oat aphid clone will measure its response to volatiles from barley yellow dwarf-infected wheat plants and volatiles will be analyzed as above. Bioassays with pea aphid will determine if aphid performance is improved on the infected plants. If so, aphid responses to volatiles from infected plants will be measured.