Sources of Resistance to Fusarium oxysporum f. sp. conglutinans, race 2

Abstract Since its introduction more than 50 years ago, monogenic dominant “Type A” resistance has successfully controlled cabbage yellows, caused by Fusarium oxysporum Schlect. f. sp. conglutinans (Wr.) Snyd. & Hans., race 1 (FOCI). Recently, a new pathotype capable of overcoming Type A resistance was found in California and designated race 5 (3). Investigations of the relationship among the races revealed that race 1 and race 5 were more closely related to each other than they were to the other races, justifying the reclassification of the F. oxysporum on crucifers (P.W.B., unpublished data). F. oxysporum f. sp. conglutinans race 5 is now designated race 2 (F0C2).