Complex relationships between agricultural managements and lettuce above- and belowground interactions.

CACCIA, M.G.; URCELAY, CARLOS; VIDELA, MARTIN

Lyon

Congreso; 10th Congress of the International Symbiosis Society; 2022

International Symbiosis Society

Conventional agriculture, based on the use of synthetic inputs, has negative impacts onthe ecosystems. Agroecological managements have shown to temper these negative effectsby enhancing ecological processes. Among soil biota, arbuscular mycorrhizal fungi (AMF)are plant root symbionts that improve access to nutrients. These fungi may also affect plantgrowth and biotic interactions. While it is well documented that distinct agricultural managements differentially affect AMF communities, it remains poorly studied how these changesfeedback on aboveground plant interactions.We compared the effects of AMF from conventional and agroecological management on lettuce (Lactuca sativa) mycorrhizal colonization, growth and nutrition and on the ovipositionof the leaf miner Liriomyza huidobrensis (Diptera: Agromizydae).In greenhouse, we grew lettuce in pots with soils from farms with conventional (C) andagroecological (A) managements from central Argentina. Treatments included: a) Sterilesoil (S), b) microbial filtrate without AMF (MO) c) soil with microbiota and AMF (AMF)(n=10). After 60 days plants were exposed for 48hs to L. huidobrensis mated females. Weevaluated plant biomass, mycorrhizal colonization, leaf phosphorous content, and the number of eggs that leafminers laid.Mycorrhizal colonization was four times higher with AMF from A than C treatments, although plants biomass was lower in AMF than S and MO, in both managements. Phosphorous content was significantly higher in plants with MO and AMF in comparison to S, eitherin conventional and agroecological management. The number of eggs laid in AMF treatmentsfrom agroecological fields were significantly lower compared with the rest of treatments fromboth management types. The number of eggs augmented with aerial dry mass and phosphorous content.Our results show the existence of complex relationships between agricultural managementsand vegetable interactions. While AMF from agroecological management increased mycorrhizal colonization and reduced plant growth, leaves were less preferred by leaf miners.