Tolerance of Cynodon Dactylon and Pampa Biome-Native Grasses to High Copper Content

Soil contamination by Copper (Cu) in vineyards grown in Pampa biome can change the growth and develop-ment of native and invasive herbaceous plants who cohabit these sites. The way these features change deter-mines plants' tolerance to Cu contamination and it can assure greater competitive advantage and favor plant establishment in vineyards. The aim of the current study to investigate whether invasive species Cynodon dactylon has higher tolerance to increased Cu levels than Pampa biome-native species such as Axonopus affi-nis, Paspalum notatum and Paspalum plicatulum. The native and invasive species were grown in Hoagland nutrient solution added with 0.32, 15, 30 and 45 mM of Cu for 15 days. Specific plant features, such as photo-synthetic activity, Cu content and distribution in plant organs, plant growth, root morphology and nutrient use efficiency were assessed. Increased Cu concentrations affected the development of native and invasive species in the Pampa biome. However, C. dactylon roots, even the ones subjected to excessive Cu concentra-tions, have shown longer length and bigger surface area than those of native species. C. dactylon also stood out for maintaining high nutrient use efficiency and root (organ where Cu accumulation prevailed) dry mat -ter production, even at high Cu concentrations. A. affinis stood out for its significant ability to maintain photo-synthetic activity, although it was not enough to maintain high plant growth rates. All these responses have indicated that C. dactylon has higher tolerance to Cu than Pampa biome-native species, a fact that may be contributing to its establishment in vineyards contaminated with Cu in Southernmost Brazil. (c) 2023 SAAB. Published by Elsevier B.V. All rights reserved.