ESPÉCIES DE Helicotylenchus ASSOCIADOS À CULTURA DE MILHO NO SUDESTE DO ESTADO DE GOIÁS

Abstract

The nematode Helicotylenchus sp. has been extensively studied by nematologists, mainly due to the increase in population in agricultural analyses. Most of the time, this nematode is identified only by the genus, not identifying the species. For corn, few studies in the literature have evaluated the association of the crop with spiral nematode. This work aimed to identify the species of Helicotylenchus associated with corn in the Southeast region of the State of Goiás, carrying out a survey of the main species of Helicotylenchus present in corn growing areas in this region and thus identifying, from the morphometric taxonomy, the main species and nematode parasitism when associated with corn cultivation. The survey was carried out in seven cities in Southeast Goiás: Catalão, Ipameri, Cumari, Ouvidor, Urutaí, Campo Alegre and Pires do Rio, collecting 400 samples in 40 different areas. The nematode frequency and abundance were calculated for each city. The association of H. dihystera was observed in 70% of the corn crop samples in the seven cities surveyed. In the samples collected in the cities of Campo Alegre de Goiás and Ouvidor, 100% frequency of the spiral nematode was observed. The endoparasite of the spiral nematode was also confirmed because it was found inside the corn root. However, symptoms were found in the corn roots, with darkened and necrotic rootlets, and these symptoms may be directly associated with H. dihystera. This is the first report of the association of H. dihystera to corn in the Southeast region of Goiás.