Physiological Traits and Biomass Production of Two Euterpe Species under Drought Stress

Our aim here was to evaluate the effects of drought stress on plant growth rate, biomass production, and physiological traits of endemic Euterpe species (Euterpe precatoria Mart.and Euterpe oleraceae Mart.) from Brazil's Legal Amazon at greenhouse conditions. We characterized photosynthesis, gas exchange parameters, total chlorophyll concentration, plant water concentration, plant growth rate, and dry biomass production using four drought stress treatments (e.g., 25, 50, 75, and 100% of soil field capacity) considering two Euterpe species (E. precatoria and E. oleraceae). We found the highest values of net photosynthesis, F-v/F-m, chlorophyll b concentration, root dry biomass, and shoot dry biomass production on pots where E. oleraceae was cultivated. On the other hand, E. precatoria showed the highest values of non-photochemical quenching, carotenoids, stomatal conductance, photochemical quenching, energy excess, and water use efficiency at 25% of the soil field capacity. Our findings suggest that (1) the drought stress can change both physiological responses and dry biomass production of Euterpe species; (2) E. oleraceae showed the highest biomass production in our experiment, but E. precatoria showed the highest water use efficiency; and (3) we could consider E. precatoria more resistant to drought stress than E. oleraceae. The drought stress altered Euterpe physiological traits, and dry biomass production. Euterpe species may create different pathways into their life history to produce biomass and improve their own performance even submitted in drought conditions.