Differences among red-skinned potato cultivars and their response to Meloidogyne species

The reproduction and damage caused by Meloidogyne incognita , M. javanica , and M. konaensis were compared on the red-skinned potato cultivars Desiree, Mountain Rose, Pink Pearl, and Red Thumb. Desiree was susceptible to the rootknot nematodes evaluated and exhibited tolerance to the nematodes as well. Mountain Rose was resistant and tolerant to M. incognita and M. konaensis but susceptible and intolerant to M. javanica . Pink Pearl was susceptible to all three nematode species and was tolerant to M. javanica and M. konaensis but not to M. incognita . Red Thumb was susceptible to M. incognita but resistant to M. javanica and M. konaensis . Red Thumb was intolerant to all three root-knot nematode species. Penetration and nematode development were evaluated in another experiment. Fewer M. incognita penetrated Mountain Rose than M. javanica (7% vs. 39% of inoculated J2). The few M. incognita that penetrated Mountain Rose developed slowly, and males were observed in Mountain Rose tubers that were infected with M. incognita . On Red Thumb, penetration by M. incognita was higher (38%) than M. javanica (13%), and M. incognita developed faster reaching a fourth-stage juvenile in 12 days. A unique relationship and specific interaction between Mountain Rose and M. incognita and between Red Thumb and M. javanica was found. Further understanding of this specific resistance might be useful and practical in breeding potato resistant to multiple species of Meloidogyne .