How do highly branched (colonial) mutants of Fusarium graminearum A3/5 arise during Quorn myco-protein fermentations?

Chlorate-resistant, highly branched (colonial) mutants and auxotrophic mutants were used to study the nuclear distribution, morphology and growth of heterokaryons of the Quorn myco-protein fungus, Fusarium graminearum A3/5. The results showed that for several complementary homokaryons, even a strong selective pressure was insufficient to maintain heterokaryons in a 'balanced' condition (i.e.