Reação de clones de batata-doce ao Meloidogyne incognita Raça 1

Abstract

The aim of this work was to evaluate the reaction of sweet potato accessions to the gall nematode Meloidogyne incognita race 1. Thirty accessions from breeding programs of Federal University of Jequitinhonha and Mucuri Valleys (UFVJM) and fifteen accessions from Federal University of Tocantins (UFT), together with five cultivars, were evaluated between February and June 2006 under greenhouse conditions. Experimental design was completely randomized, with four replicates. Branches of each genotype were planted on expanded polystyrene trays filled with commercial substrate Plantmax® , and each plot was composed of six plants. Inoculation was done at seventeen days after planting at the proportion of 30 eggs mL-1 substrate. At ninety days after inoculation, plants were collected and their roots were washed and stained with bordeaux and tartrazine for determination of the egg mass index per root system. The cultivars Brazlândia Branca and Palmas were used as susceptible and resistant controls, respectively. There was a great variability among genotypes as to level of resistance to the pathogen. The cultivar Brazlândia Roxa and thirteen accessions were highly resistant to the gall nematode. The cultivar Brazlândia Rosada showed moderate resistance to the gall nematode.