Reaction of corn genotypes to parasitism from Meloidogyne incognita breed 1 and M. paranaensis - DOI: 10.4025/actasciagron.v31i4.761

Abstract

The use of corn hybrids and genotypes resistant to root-knot nematodes in crop rotation systems reduce the population of nematodes, preventing losses and allowing for the use of more susceptible genotypes. In this study, the resistance of eighteen hybrids of corn to parasitism of Meloidogyne paranaensis and M. incognita breed 1 were evaluated in a greenhouse. The plants were inoculated with 5,000 eggs and possible juveniles of each nematode in a completely randomized design, using ten replicates for each treatment with nematodes, and five replicates for the treatment without inoculation (control). The root staining technique using acid fuchsin was also applied, according to Byrd et al. (1972). Sixty days after the inoculation, the roots systems were collected, washed and evaluated for penetration, egg production and estimated reproduction factor (RF). The results showed that, for M. paranaensis, the RF varied from 0.01 to 0.08, while for M. incognita the variation was from 0.01 to 0.03, showing that all corn genotypes were resistant, presenting a RF < 1.