Indução de estresse salino in vitro de Hylocereus spp.

Abstract

The pitahaya is a specie from cactacea’s family that has been gaining more prominence in the market, in addition to being high tolerant to drought. Plant tissue culture is a biotechnological technique that has been used to high multiplication rates as well as enabling the selection of genotypes tolerant to abiotic stresses. The aim of this study was to evaluate the behavior of pitahaya species in function salt-stress induction in vitro. The experiment was conducted at the Laboratório de Cultura de Tecidos Vegetais do Departamento de Agricultura da Universidade Federal de Lavras, Lavras-MG. Apical fragments of 1.5 cm from the species Hylocereus undatus, Hylocereus polyrhyzus, and the hybrid between the species Hylocereus polyrhizus x Hylocereus undatus were multiplicated in vitro, submitted to concentrations of NaCl (0, 50, 100 and 150 mM) in MS culture medium, the design used was entirely randomized in a 3 x 4 factorial scheme After 60 days of cultivation, the morphometric and physiological characteristics of plants in response to salt stress condition were evaluated. NaCl concentrations influenced the morphometric variables such as plant length, number of roots, length of the biggest root, fresh and dry mass, number and lenght of budding. H. undatus showed more reductions in its parameters, while the H. polyrhyzus showed some degree of tolerance. The physiological variables, like electrolyte leakage and membrane integrity increased according to the increment in NaCl concentrations, independent of the pitahaya species. It was considered that the morphometric variables, dry mass accumulation, and physiological variables allowed the identification of the effects of salinity, concluding that the species evaluated in this study are moderately adapted.