The objective of this work was to select sweet potato resistant clones to the races 1 and 4 of Meloidogyne incognita, and measure the efficiency of the selection method used, by means of the estimation of genetic and environmental coefficients of variation, and broad-sense heritabilities. We evaluated 21 accessions of the clonal garden of the Universidade de Brasilia, and three cultivars of sweet potato (Brazlândia Branca, Brazlândia Roxa and Amarela). The experiment was carried out in a greenhouse with a randomized block design in simple arrangement, with 24 treatments, four replications and three plants per plot. The inoculation of the pathogen was made thirty days after planting the slips and, after ninety days, the counting of the average number of egg masses of the infected plants was completed. Clones were considered resistant when presented a number of egg masses per root system from 0 to 1.9, moderately resistant 2.0 to 2.9, moderately susceptible 3.0 to 3.9, and, susceptible 4.0 to 5.0. From 24 clones analyzed, nine (37.5%) were classified as resistant to the race 1 of M. incognita, and 16 (66.67%) were classified as resistant to the race 4 of M. incognita. The clones 1200, 1210, 1199, 1229, 1230, 1202, 1231, 1216 and 1209 were resistant to the two races tested of M. incognita. The resistance of the plants to these two races of root-knot nematodes presented high heritability, and the relationship between the coefficients of genetic and environmental variation of the experiment to resistance to race 4 of M. incognita was shorter than that one found in the another experiment, that aimed resistance to the race 1.
Ipomoea batatas; Meloidogyne spp.; root-knot nematodes; heritability
