Pathogenicity and Histopathology of Meloidogyne graminis Infecting 'Tifdwarf' Bermudagrass Roots

In a greenhouse experiment Meloidogyne graminis was pathogenic to 'Tifdwarf' bermudagrass, causing significant reduction in plant weight. Roots and tops of inoculated grass weighed 28.4% less than non-inoculated grass 8 months after inoculation. Clipping weight of nematode-infected turf weighed 68.9% less than clippings from non-infected turf. Histopathological studies showed that the head of the female nematode penetrated the vascular system and resulted in giant cell formation in the feeding area. The nematode body remained in the cortex parallel to the vascular system. Eggs were deposited at the posterior of the nematode in a gelatinous matrix in the cortex. M. graminis fed with its anterior end oriented toward the growing root tip. M. incognita had no set body orientation pattern when feeding on bermudagrass.