Parâmetros populacionais e correlação entre características da resistência a nematóides de galhas em alface

Abstract

The aim of this work was to estimate population parameters and to quantify the association degree among the characteristics related to Meloidogyne incognita race 1 resistance in lettuce F4, in order to contribute improvement programs in the incorporation of the resistance to root-knot nematodes. The experiment was carried out in a greenhouse, using expanded polystyrene trays with 128 cells, in a completely randomized blocks design with three replications and eight plants per plot. The substrate was infested with Meloidogyne incognita race 1 eggs, in the proportion of 30 eggs.cm–3 of substrate. The evaluation was made 45 days after the inoculation for galls incidence, galls number, eggs masses number and eggs number. The estimated high broad heritability was higher than 45%, reaching 72% for eggs number. High and positive genetic correlation exists among all of the evaluated characters and the eggs number provides the greatest gain of selection.