Histopatologia Comparada das Raízes de Cultivares Suscetível e Resistente de Soja Inoculadas corn Meloidogyne paranaensis

The resistance to species of Meloidogyne can be defined as some factor or factors in the plants that inhibit the reproduction of these nematodes; the giant cells can be poorly formed and, feeding in these cells, the nematode develop itself little or slowly. The objective of this study was to compare the anatomical alterations caused by Meloidosyne paranaensis in roots of resistant and susceptible soybean cultivars, aiming to identify mechanisms of resistance involved in these interactions. The cultivars CD 203 (resistant) and CD 214 RR (susceptible) were inoculated with 2,000 second stage juveniles J 2 ) of M. paranaensis and, 25 days after the inoculation, root-knot segments from both cultivars were included in paraffin and cut in cross sections. Other segments were processed for observation and documentation in scanning electron microscope. The important anatomical alterations were photographed and the structures were measured. It was observed significant differences in the number and diameter of the giant cells between the cultivars. However, there were no significant differences in the diameter of the parenchyma cells, vascular cylinder and thickness of cortical parenchyma between cultivars.