Motilidade e migração de nematoides em ambientes salinos

Abstract

Plant-parasitic nematodes are among the main pathogens that cause disease and damage to crops, causing serious agricultural damage worldwide. However, another limiting factor for agricultural production, especially in the semiarid region of northeastern Brazil, is the salinization of soils caused by natural or man-made factors. Although there are studies related to the interaction of soil texture, temperature and capture in the movement of plant parasites, information on the behavior of these parasites in saline environments is scarce. Thus, the present study aimed to evaluate the motility of Meloidogyne enterolobii and Pratylenchus coffeae and the vertical migration of P. coffeae in saline environments. Motility was evaluated by submitting juveniles and adults of M. enterolobii and P. coffeae in saline solutions of NaCl, CaCl2, MgCl2 with concentrations of 0.0 (control with distilled water), 0.25; 0.5; 0.75 and 1M, and in a mixed solution (combination of the three salts in a 7:2:1 ratio), at 2,4, 6 and 8 days of exposure. The migration of P. coffeae was studied in segmented soil columns, 10 cm long, and with an internal diameter of 4.4 cm, filled with saline soil (mixture of NaCl, CaCl2, MgCl2) and non-saline soil, and the evaluations were performed at 2, 4 and 6 days after inoculation.The increase in the salt concentrations of all the evaluated salts reduced the motility of both nematodes. The vertical migration of P. coffeae was negatively affected by soil salinity.