Resistance of new Italian potato breeding clones to cyst and root-knot nematodes

Abstract

Screening tests were conducted in glass-houses in 2006 and 2007 to assess the reaction of 27 new Italian potato (Solanum tuberosum) breeding clones to the potato cyst nematode, Globodera rostochiensis pathotypes Ro1 and Ro2, and to rootknot nematodes, Meloidogyne incognita host race 1 and M. javanica. Seven potato cultivars, known to be resistant to cyst nematodes, were also screened for their response to root-knot nematodes. The tests were conducted in 1 dm3 clay pots containing steam sterilized sandy soil infested with 10-15 eggs/cm3 of either pathotype of G. rostochiensis or 10,000 eggs and second stage juveniles/ pot of either root-knot nematode species. The glass-houses were maintained at 20 ± 2 °C for G. rostochiensis and at 26 ± 2 °C for Meloidogyne spp. The clones CS 8617 and MN 3-1469 R2 were resistant to all three nematode species, and the clone AND 97-15, known to be resistant to all European pathotypes of G. rostochiensis and G. pallida, was also resistant to M. incognita and moderately resistant to M. javanica. Fourteen of eighteen clones tested in 2006 and seven of the nine clones tested in 2007 were resistant to both pathotypes of G. rostochiensis. Two clones were resistant to both root-knot nematode species in 2006 and one clone moderately resistant to M. incognita and one moderately resistant to M. javanica in 2007. Some of the clones resistant to G. rostochiensis also possess good agronomic traits and have potential for registration as new cultivars.