Reaction of potato cultivars to root-knot nematodes

Nine potato cultivars (BRS Eliza, BRS Ana, Epagri 361-Catucha, SCS 365 Cota, BRS Clara, BRSIPR Bel, Iapar Cris, Agata and Asterix) were evaluated for resistance to eight root-knot nematode species (Meloidogyne spp.). Plants were grown in greenhouse pots containing sterilized soil and inoculated with 5,000 eggs + secondstage juveniles (J2) of M. javanica (Est J3 and J2a), M. incognita (Est I2), M. arenaria (Est A2), M. enterolobii (Est M2), M. paranaensis (Est P1), M. hapla (Est H1), M. morocciensis (Est A3), or M. graminicola (Est VS1). Fifty- five days after inoculation each plant was assessed for the number of galls and number of eggs + J2, and the nematode reproduction factor (RF) was estimated. According to our study, all cultivars were susceptible to all root- knot nematode species tested except for M. graminicola. The cultivars that were less susceptible to M. javanica were Catucha, Eliza, and Cris; to M. incognita, Agata; to M. hapla, Eliza; to M. arenaria, Cota, Clara, Asterix, Ana, Eliza, and Agata; to M. enterolobii, Bel and Asterix; to M. paranaensis, Catucha, Bel, Agata, Asterix, Cota, Clara, and Ana; and to M. morocciencis, Agata. To M. graminicola, the cultivars Eliza, Cris, and Asterix were immune, and Agata and Catucha, resistant.