AJUSTAMENTO OSMóTICO EM MUDAS DE JATOBá SUBMETIDAS à SALINIDADE EM MEIO HIDROP?NICO

摘要

In natural environments, salinity is a major impediment to the development of plants. Aiming at a better understanding of the effects it causes in the physiology of native tree species, the present study aimed to evaluate the physiological behavior of jatobá (Hymenaea courbaril L.) seedlings subjected to salinity in hydroponics. Therefore, an experiment was conducted in a greenhouse of the Laboratory of Plant Physiology of the Universidade Federal Rural de Pernambuco, adopting an experimental design completely randomized in a 3 x 2 factorial arrangement consisting of three saline treatments: Control (nutrient solution without addition of NaCl), moderate stress (addition of 50 mM NaCl) and severe stress (addition of 100 mM NaCl) and two evaluation periods (1st time evaluation: Finding the stomatal closure; 2nd time evaluation: After verification of stomatal opening of plants subjected to salinity.), with 20 repetitions for each treatment. During the study gas exchange, water relations, photosynthetic pigments content and accumulation of organic and inorganics solutes were checked. At the end of the experiment it was observed that the seedlings of jatobá adjusted osmotically after induction of severe stress, since they accumulated organic solutes that promoted the elevation of leaf turgor, resulting in stabilization of gas exchange, even after submission to severe stress.