Resistance of okra genotypes to Meloidogyne incognita race 2 and M. javanica

Twenty two okra genotypes were evaluated for resistance to M. incognita race 2 and M. javanica. The Universidade Estadual do Norte Fluminense (Brazil) maintains okra genotypes in the germplasm collection, consisting of four wild Abelmoschus species and 16 F7 lines obtained from crosses between PI-357991 (considered resistant to root-knot nematodes) and the local cvs, Piranema and Santa Cruz 47 (both susceptible to nematodes). No resistance was observed among okra genotypes to infection by M. javanica. The 16 F7 lines segregated for pathogenic reaction, and the CGO 8180A7 presented the highest resistance level to M. incognita race 2. The wild species did not show genetic resistance to both pathogens. High temperature occurring during experimental period could have increased the genotype susceptibility to the pathogens.

Abelmoschus spp.; germplasm evaluation; root-knot nematode