Parasitic Habits and Histopathology of Root-Knot Nematodes Infection on Turfgrasses

Abstract

Parasitic habits of two root-knot nematode species, Meloidogyne marylandi andM.incognitain turfgrass roots were demonstrated respectively by inoculation experiments and histopathological observation under light and scanning electron microscopy.
In host plants inoculated withM.marylandi, the root galls were entirely nothing or observed rarely slight swelling. Female bodies or developed egg masses, however, were recognized on outside of those roots. While in plants inoculated withM.incognita, small root galls and egg masses were confirmed usually on infected roots.
The giant cells in root tissues were developed in both host plants inoculated withM.marylandiorM.incognita, but their features were clearly different in morphology and forming location. Morphology of giant cells induced byM.marylandiwere usually oblong extending longitudinally in vasucular, system, and they located partially at inner tissue of pericycle near nematode establishing place. Nuclei of giant cells were enlargement and nucleus number was not so many. Such characters were similar to that of giant cells induced by other species amongM.graminis-group. While the giant cells induced byM.incognitadeveloped into almost area of vascular cylinder at infected part of nematode and they occupied around head of matured female.