Evidence for a Hemibiotrophic Association of the Pitch Canker Pathogen Fusarium circinatum with Pinus radiata.

Fusarium circinatum can be a cause of mortality in pine seedlings but it is also possible for infected seedlings to remain symptomless. The results of this study documented a biotrophic phase in symptomless Pinus radiata seedlings that can persist for at least 52 weeks. A strain of F.

Evidence for recombination and segregation of virulence to pine in a hybrid cross between Gibberella circinata and G. subglutinans.

Two species associated with the Gibberella fujikuroi species complex, G. circinata (the cause of pitch canker in pines) and G. subglutinans (avirulent on pine), were found to have limited interfertility in hybrid crosses.

Potential diversity in vegetative compatibility groupings in the California population of Gibberella circinata.

Pitch canker, caused by Gibberella circinata, is a disease affecting pines throughout the world. Although the pathogen is capable of sexual reproduction, natural populations are often comprised of very few vegetative compatibility groups (VCGs), which implies a predominance of asexual reproduction. However, even where outcrossing occurs, a population could have limited VCG diversity due to a low level of polymorphism at the loci governing vegetative compatibility (=vic loci).