Interacción entre Salvinia minima y Lemna gibba: efecto sobre el crecimiento en distintos medios de cultivo

Abstract

Nutrient uptake and competitive ability of the aquatic species Lemna gibba and Salvinia minima were evaluated. The experiment was carried out in a greenhouse and plants were grown as mono-plant cultures and mixed-plant cultures. Three different me-dia were used: tap water and the chemically defined media Lemna and Hutner 1/10. Du-ration of the experiment was 7 days. Initial and final dry weights and DIN and SRP con-centrations were determined. Relative growth rates (RGR) and nutrient uptake rates were calculated. L. gibba´s RGR values increased significantly in Hutner 1/10 medium when types of cultures were analyzed separately. RGR values decreased in Lemna and Hutner 1/10 media in mixed-plant cultures. S. minima did not show significant differences in its RGR values. In mono-plant cultures N and P uptake rates in Lemna medium were sig-nificantly larger for L. gibba. In Hutner 1/10 medium P uptake rate was greater for S. min-ima and N uptake rate was larger for L. gibba. The presence of S. minima negatively affected L. gibba´s growth.