Twenty - one populations of the nematode galls (Meloidogynespp.) From eight municipalities in the central region of the State of Rio Grande do Sul were characterized biochemically through isoenzymeesterase. At the time of sampling, the plants sampled were chlorotic, poorly developed and with the deformed root system, characteristic symptoms of the attack of the gnats nematode. Using the aisoenzyme esterase, only the VS1 (Rm 0.70) esterase typology of M. graminicola was identified at all sites sampled.
