Studies on glucosinolates in clubroot resistant selections and susceptible commercial cultivars of cabbages

Summary Heads of 59 commercial cabbage cultivars, all susceptible to clubroot disease, and of 86 individual clubroot resistant cabbage plants of various breeding selections were analysed for their composition in glucosinolates, determined by quantifying their hydrolytic breakdown products, thiocyanate, goitrin, and volatile isothiocyanates. The mean thiocynate ion content was significantly lower in the breeding selections (120 g/g dry weight) than in the commercial cultivars (204 g/g). In contrast, the mean goitrin content was significantly higher in the breeding selections (193 g/g) than in the commercial cultivars (35 g/g). Similar to goitrin, the range of volatile isothiocyanates and total glucosinolate were higher in the breeding selections, but the mean contents of each were not statistically different between selections and cultivars. Fourteen cultivars and four selections were found to be free of goitrin; three cultivars, but no breeding selection were free of volatile isothiocyanates. The breeding selections will provide germplasm for breeding new clubroot resistant and low glucosinolate cultivars.Contribution No. J-965.