Evaluation of the physiological activity of Ilex paraguariensis St. Hill

Abstract

Ilex paraguariensis St. Hill, popularly known as yerba mate, is a species native to South America, occurring in Argentina, Paraguay and Brazil, being widely cultivated in southern Brazil and belongs to the Aquifoliaceae family. The evaluation of the physiological activity of plants is important because it makes it possible to understand their behavior in different environments, according to abiotic and biotic influences. Thus, the objective of this work was to evaluate the physiological activity of adult plants of Ilex paraguariensis, quantifying the photosynthetic variables before and after cutting the branch of the mother trees. Two individuals per sex of I. paraguariensis were used, that is, two samples of “Male Yerba Mate” and two of “Female Yerba Mate”. To obtain the samples, a branch of each individual was cut with the aid of pruning shears, resulting in four samples, two per sex. Physiological activity was measured using a Licor™ gas exchange meter, model Li-6400XT, where photosynthesis (P), transpiration rate (Trmmol) and stomatal conduction to water (Cond) values were obtained. It is concluded that there is a big change when the branch is cut for measurement using Licor LI-6400xt, which causes a big error when quantifying the physiological activities of this plant. Further studies are suggested to perform this measurement more accurately.