Influência do parasitismo de Psittacanthus robustus (Mart.) Mart. nos padrões populacionais e respostas fisiológicas de Vochysia thyrsoidea Pohl

Abstract

This study sought answers in the field of Ecophysiology to better understand the parasitism relationship between the species Psittacanthus robustus and Vochysia thyrsoidea. It was possible to verify which were the main physiological parameters affected by this relationship. The physiological responses related to photosynthetic efficiency, as well as water status and leaf senescence between parasitized and non-parasitized plants, were compared. Furthermore, through a generalized linear model, the key variables of this relationship that influence the mortality of V. thyrsoidea were classified. The studies were conducted in a Cerrado Rupestre area, in the municipality of Carrancas, in the south of Minas Gerais. Among the main results, it was observed that mortality is more related to host height and number of parasites. It was possible to observe that higher trees are more likely to survive, and the higher the number of parasites, the lower the chance of host survival. It was found that photosynthetic efficiency and water status were influenced by parasitism and senescence was not, although it was verified that parasitized branches were often bare. Thus, the present study was of paramount importance to increase knowledge about the parasitism relationship between those species. The study allowed to understand when parasitism can lead the host to death and which physiological parameters are most affected by the presence of the parasite. However, further studies are still required, with more specific goals, for the completion of the answers of this study.