Pathogenicity of Meloidogyne spp. (Tylenchida: Meloidogynidae) from Brazil and Central America on two genotypes of Coffea arabica

Among the most damaging root-knot nematode species, Meloidogyne exigua, M. paranaensis, M. incognita, M. arabicida, M. izalcoensis and M. mayaguensis are major agronomic constraints in coffee-growing areas in Brazil and other Latin American countries. The resistance reaction to those six species was studied for the H 419-5-4-5-2 progeny, derived from the artificial hybridization between Catuai Amarelo 'IAC 30' x Timor Hybrid UFV 445-46 selection. The Catuai Vermelho IAC 144 genotype was used as susceptibility control for Meloidogyne spp. The genotypes were inoculated with 6,000 eggs/plant and the experiment was set up in a completely randomized design, replicated 10 times for each Meloidogyne species and genotype. The evaluation was performed at 240 days after inoculation and the reproduction factor (RF= Final population/6000) was used as the variable to evaluate resistance. M. exigua caused typical rounded galls mostly on new roots, and egg-masses were produced mostly in the cortex under the root epidermis. M. incognita, M. paranaensis and M. arabicida caused swollen roots, peeling and cracking of cortical root tissue. No symptoms were observed for M. mayaguensis. M. izalcoensis induced very small galls, mostly on the extremity of new roots. Egg-masses were produced outside the roots in large quantities. The genotype IAC 144 was susceptible (FR>1.0) to all Meloidogyne spp). studied, except to M. mayaguensis. The nematode isolate used in this experiment seems to be a weak parasite for coffee. The H 419-5-4-5-2 progeny was resistant to M. exigua (FR<1) and susceptible to M. incognita, M. paranaensis, M, arabicida and M. izalcoensis.