Physiological fitness cost associated with Glyphosate resistance in Echinochloa Colona

Abstract

The quantitative assessment of physiological fitness costs associated with glyphosate resistance in Echinochloa Colona from the Tropical Ord River region of Western Australia was conducted with plant materials selected from within a single Glyphosate-resistant population. Under non-competitive conditions, the susceptible (S) Phenotype had greater leaf area and aboveground and root biomass as well as a higher growth rate compared to plants of the resistant (R) Phenotype during the vegetative growth stage. At the reproductive stage, plants of the S Phenotype also produced more vegetative and reproductive aboveground biomass than the R Phenotype. A psychological fitness cost estimated by an observed 31% reduction in total seed mass or 22% reduction in the number of seeds was associated with. The R Phenotype. The results clearly suggest there is an evolutionary trade-off between Glyphosate resistance and vegetative and reproductive growth in E. Colona in glyphosate-free environments.