Glyphosate tolerant Lotus spp. as rhizoremediation tool for Humid Pampa soils

MASSOT, F; SMITH, E; GIULIETTI, AM; MERINI, LJ

Mar del Plata

Encuentro; VIII Encuentro Latinoamericano y del Caribe de biotecnología ? REDBIO; 2013

REDBIO

Glyphosate is the most applied herbicide in intensive agricultural practices in Humid Pampa and designing biotechnological strategies based on phytoremediation rises as an alternative to minimize its environmental impact. The first step on this approach is finding the appropriated glyphosate tolerant vegetable species. The aim of this work was to assess the glyphosate tolerance of Lotus tenuis and L. corniculatus, based on their agronomical properties and suitability with the strategies specifically designed for this region. Different dose-response assays were carried out considering the capacity of the postulated species to eventually grow in contaminated soils and endure agrochemicals drift. A grow assay, performed in a maximum bioavailability Murashige-Skoog  semisolid agar medium at 5 glyphosate concentrations, corresponding to an agronomic dose spread in different soil profile depths. A foliar application assay, were plantlets were sprayed at 5 glyphosate doses according to agronomic standards. The germination rate, plant survival, biomass and shikimate tissue concentration as biochemical tracer, were registered. The results showed no statistical difference between controls and levels of 1 mg kg-1 and  700 g ha-1 for grow and application assays respectively. According to the tolerated glyphosate levels, both Lotus species are promising tools to be employed to remediate chronically polluted soils.