Multigene phylogenetic study of Cyclaneusma species

Cyclaneusma Needle Cast is associated with the fungal pathogen Cyclaneusma minus. The disease has led to significant losses of Pinus radiata production in New Zealand, but the disease appears less serious in Australia. Two cultural morphotypes of C. minus have been discriminated in New Zealand, and isolates from Australia also correspond to these two morphotypes. To examine if the two morphotypes of Cyclaneusma are different species, phylogenetic analysis using sequences from five gene regions (rDNA ITS, mt-LSU, n-LSU, tef-1 and bT-1) was conducted. This study revealed that C. minus consists of two distinct clades which correspond to the two morphotypes. One morphotype ('verum') was more closely related to Cyclaneusma niveum than to the other morphotype ('simile'). A morphological description is required to formalise the new species represented by the 'simile' clade; an investigation of the individual pathogenic behaviours of both morphotypes is also required.