Determination of Resistance Levels of Some Onion Cultivars or Inbreed Lines with Fusarium Testing at Seedling Stage

This study was carried out to determine the resistance levels of some onion genotypes in Yalova onion gene pool by Fusarium testing during seedling stage. The isolate used in the study was Fusarium oxysporum f. sp. cepae , which causes damping off during the seedling stage and later basal rot in onion bulbs. The variance analysis for the onion seedling test and the mean differences against control were analyzed by using General Linear Model of the Tukey test. The germination rate of control seeds varied between 72% to 98%, while the germination rate of inoculated seeds varied between 39% to 93%. Texas Early Grano 502 showed the highest level of resistance with a survival rate of 83.8%, and resistance levels of 19Y07 and 19Y142 genotypes were higher than other genotypes. Resistance levels of 19Y51, 19Y15 and 19Y73 genotypes were lower than other genotypes. Akgün 12 showed moderate resistance with a survival rate of 59.6%. Determining the resistance levels of these onion genotypes during the seedling stage may be a preliminary step towards further studies