Races of the celery pathogen Fusarium oxysporum f. sp. apii are polyphyletic

Sixteen Fusarium oxysporum species complex (FOSC) isolates that had been collected from celery with symptoms of Fusarium yellows were next generation sequenced on an Illumina Mi-Seq at the University of California at Davis Genome Center to >8.3X coverage. The isolates included the following: six Fusarium oxysporum f. sp. apii (Foa) race 2 (003, collected in Oxnard, CA in 1993; 226.2A and 247.1A, collected in Oxnard, CA in 2011; 067, collected in 1994 in Santa Maria, CA; 207A1A2 and 258.1B collected in Santa Maria, CA in 2010 and 2011, respectively); the new and highly aggressive Foa race 4 (274.AC), which was first observed in Camarillo, CA in 2013; a Foa race 1 (268.1) which was collected in a celery germplasm plot in Davis, CA in 2012; and a Foa race 3, which was deposited by Shirley Nash Smith to a culture collection in 1981; and 7 FOSC that were isolated from symptomatic tissue (with either Foa race 2 or race 4), but appear to be avirulent, i.e., do not cause the iconic vascular discoloration (270.A from Berlin, WI in 2012; 223.1A from Oxnard, CA in 2010; 226.1A, 226.1B, and 241.1A from Oxnard, CA in 2011; and 221-B and 261.1A from Santa Maria, CA in 2010 and 2011, respectively).