Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 6/23/2000
Publication Date: N/A
Technical Abstract: Several clones with resistance to Globodera rostochiensis pathotype Ro2 were identified in a potato breeding population with a pedigree of Solanum tuberosum ssp. tuberosum, S. tuberosum ssp. andigena, and S. vernei. Intercrossing these clones then outcrossing their progeny to cultivars with Ro1 resistance produced several clones with resistance to both pathotypes. Two of these clones were tested in field plots with mixed infestations of pathotypes Ro1 and Ro2. Controls were cultivars Kanona that is resistant to pathotype Ro1 and Katahdin that is susceptible to both pathotypes. Experimental plots were two rows 1 m apart and 3 m long and each clone or cultivar was replicated four times. Soil samples consisting of 20 probes 6 cm deep were taken from each plot after harvest of each year. Cysts were extracted from a 300 cc subsample of soil from each plot and crushed to determine the number of viable eggs. After two years, the G. rostochiensis spopulation density increased 228% following the cultivar Katahdin that has no resistance and 26% following the cultivar Kanona that is resistant to only pathotype Ro1. The G. rostochiensis population density decreased 96% after two years of growing the advanced clones R6-4 and NY121 that possess resistance to both pathotypes.