RT Journal Article
T1 Evidence, Mechanism and Alternative Chemical Seedbank-Level Control of Glyphosate Resistance of a Rigid Ryegrass (Lolium rigidum) Biotype from Southern Spain
A1 Fernández Moreno, Pablo T.
A1 Bastida Milián, Fernando
A1 Prado, Rafael de
AB Rigid ryegrass (Lolium rigidum) is one of the most troublesome weeds in different cropsin the Mediterranean region. A rigid ryegrass biotype from an olive grove in Jaén province(Andalusía, southern Spain), potentially resistant to glyphosate (RG), was tested for itsresistance level through dose-response assays using a susceptible biotype (SG). Totest the hypothesis of a non-target-site-based resistance, as point mutations are farless common mechanisms of glyphosate resistance, studies were also conducted toelucidate whether resistance was associated with biochemical, metabolism, molecularand/or physiological mechanisms. Alternative herbicide-based control options, includingsingle-herbicide or herbicide mixtures with glyphosate, applied at seedling, tillering orfull heading stages, were tested in field experiments for 2 years for their efficacy againstrigid ryegrass plants and their effects on the soil seed bank. Resistance levels of theRG biotype were 23- (LD50) and 7-fold (GR50) higher compared to the SG biotype. TheSG biotype exhibited a significantly greater shikimic acid accumulation than the RG one.At 96 HAT, 58 and 89% of applied 14C-glyphosate was up taken by leaves of RG andSG biotype plants, respectively, and, at this time, a significantly higher proportion of theglyphosate taken up by the treated leaf remained in its tissue in RG plants comparedto the SG ones. The RG biotype did not reveal any point mutation in the glyphosatetarget site EPSP synthase. Overall, results confirmed reduced glyphosate uptake andtranslocation as being the mechanism involved in glyphosate resistance in the RGbiotype. RG biotype responses to the alternative treatments tested in situ indicatedthat herbicide applications at the later growth stage tended to be less effective in termsof immediate effects on population size than earlier applications, and that only in somecases, the removal of at least 85% of the RG biotype was achieved. However, with fewexceptions, the alternative treatments tested appeared to be highly effective in reducingthe seed bank irrespective of the growth stage. The frequency of the resistant phenotypein the progeny of surviving plants of the RG biotype was dependent on treatment.Results suggest that a potential exists for effective management of glyphosate-resistantrigid ryegrass in olive groves in southern Spain.
PB Frontiers Media
SN 1664-462X
YR 2017
FD 2017
LK http://hdl.handle.net/10272/15266
UL http://hdl.handle.net/10272/15266
LA eng
NO Fernández-Moreno, P. T., Bastida, F., & Prado, R. de (2017). Evidence, Mechanism and Alternative Chemical Seedbank-Level Control of Glyphosate Resistance of a Rigid Ryegrass (Lolium rigidum) Biotype from Southern Spain. Frontiers in Plant Science, 8. https://doi.org/10.3389/fpls.2017.00450
NO This work was funded by the Spanish Ministry of Economy and Competitiveness (AGL2016-78944-R), and partially by Monsanto Europe S.A. (Brussels).
DS Repositorio Institucional de la Universidad de Huelva
RD 31 may 2026