Estimation of genetic parameters and resistance to Meloidogyne spp. in melon genotypes

Root-knot nematodes (Meloidogyne spp.) are one of the major pests of agricultural crops worldwide. In Brazil, these nematodes are widely distributed in melon fields, and there are no reports of resistant melon cultivars. This study aimed to estimate genetic variance components for the selection of melon genotypes resistant to Meloi-dogyne incognita, M. javanica, and M. enterolobii. Two experiments were carried out in a completely randomized design, the first with 14 replications and the second with 10 replications, in a factorial design. Thirteen melon genotypes were tested. In both experiments, the total number of eggs and juveniles (TNEJ) was estimated and used to determine the reproduction factor (RF) and reproduction index (RI) of nematodes. Melon genotypes showed wide genetic variability in resistance to the three nematode species, resulting in high estimates of heritability (92%) and accuracy (96%). Such findings indicate the possibility of genetic gains with selection. Melon AC-09, PI157082, and 'Ouro' were found to be sources of resistance to M. incognita, M. javanica, and M. enterolobii, respectively.