Solanum palinacanthum: Broad-spectrum resistance to root-knot nematodes (Meloidogyne spp.).

BACKGROUND Root-knot nematodes (RKN,Meloidogynespp.) are harmful phytophagous pests ofSolanumspp. Some RKN species are becoming worldwide problems because of their virulence to RKN-resistantSolanumspecies. A newSolanumspecies carrying broad-spectrum resistance toMeloidogynespp. is required for the effective management of this pest. Here we sought to determine the host suitability of RKN toSolanum palinacanthum, a wildSolanumspecies, and to evaluate its potential effectiveness in RKN management. RESULTS We identified an RKN-resistantSolanumspecies,S. palinacanthum, by screeningSolanumaccessions. We tested its spectrum of resistance to commonMeloidogynespp. in Japan. In pot tests inoculated with second-stage juveniles,S. palinacanthumshowed poor host suitability forMelidogyne incognita,M. arenariagenotypes A2-J and A2-O,M. javanicaandM. hapla, indicating broad-spectrum resistance to RKN. The development ofM. incognitawithinS. palinacanthumroots was significantly poorer than that in susceptibleS. melongenaandS. lycopersicumat 10 and 21 days after inoculation. Microplot tests confirmed that the number of second-stage juveniles in plots whereS. palinacanthumgrew and root galling of the root system were significantly lower than those of susceptibleS. melongena, suggesting that the resistance could be used to manage RKN under field conditions. CONCLUSION S. palinacanthumshowed poor host suitability to allMeloidogynespp. tested in this study, and it thus has the potential to be used as a genetic resource with broad-spectrum RKN resistance, and it could be effective against multiple RKN species in a field.