THE GENETICS OF PHYTOTOXIN PRODUCTION BY PLANT PATHOGENIC FUNGI

Little is known about the genetic control of phytotoxin production by plant pathogenic fungi. The production of host-selective toxins known to play a role in disease development has been genetically analyzed in three species of Cochliobolus. In C. heterostrophus, a single genetic locus with two alleles has been identified controlling the production of HMT-toxin. This locus appears to be at or near the breakpoint of a chromosome rearrangement. Single genetic loci have also been identified controlling the production of HC-toxin by C. carbonum and HV-toxin by C. victoriae. The locus in C. carbonum may be a cluster of tightly linked genes.