D3093: Colonization and impact of arbuscular mycorrhizal fungi and pea aphids on a diverse panel of field pea genotypes

The use of mycorrhizae is a promising approach for developing resource-efficient and sustainable agricultural systems. Arbuscular mycorrhizal fungi (AMF) colonize plant roots and benefit plants by enhancing phosphorus availability and indirectly influencing densities of insect pests. Although the plant-AMF association can improve plant growth, neutral or negative effects can also occur depending on the AMF and the plant species involved. We conducted a greenhouse experiment to investigate the impact of AMF on growth and health of 20 diverse genotypes of field peas (Pisum sativum L.) within four groups (organic, modern, historically important, and protein-rich lines) and how susceptible the genotypes were to pea aphids (Acyrthosiphon pisum Harris). In the first study, half of the plants were inoculated with AMF while the other half were non-inoculated controls, with all grown in a sterilized, low-phosphorus medium. Half of the plants were sampled at flowering to assess percent AMF root colonization and effects of AMF on leaf chlorophyll, plant vigor, and plant biomass. The second experiment investigated pea aphid population growth on the same genotypes, with half of plants receiving extra phosphorus in the growing medium. Two weeks after planting, each plant was inoculated with three female adult aphids and aphid densities and plant weight were assessed after ten days. AMF root colonization and effects of AMF on plant vigor, leaf chlorophyll, and shoot weight varied according to genotype. Results from the second experiment are forthcoming. This research emphasizes plant-genotype interactions with AMF and insect-pests, aiding optimal use of mycorrhizal symbionts in agriculture.