existence of a type isolate (NRRL-792) with nomenclatural
priority (although the type assigned was a neotype designated
by later authors who considered it a synonym of P. chrysogenum).
However, Species A and B were not accounted for by
known type isolates, demonstrating the novelty of these
species. Here, based on our molecular diagnostic assay, they
have been assigned type isolates (NRRL-A1399 and NRRL-
35635) and are formally named P. floreyi and P. chainii respectively.
We conclude that the divergence of the Chrysogenum
complex occurred z0.75 MYA with more recent divergences
arising z0.5 MYA; however the precise relative positioning of
species could not be inferred with strong statistical support.
Identifying the relative branching order amongst these four
cryptic species may require the analysis of much larger
datasets, whole genome sequences, or may not be possible.
We designed species-specific diagnostics for P. chrysogenum, P.
rubens, P. chainii and P. floreyi allowing rapid detection via PCR
direct from conidia. We then applied our diagnostic tools by
air sampling in London and the Underground to demonstrate
fast environmental detection of Chrysogenum complex fungi.
This tool confirmed that both P. chrysogenum and P. rubens are
common fungi with their distributions varying between
sample locations. Additionally, MAT1-1 and MAT1-2 were
detected in both species at a ratio of near 1:1 adding further
evidence for on-going recombination in the Chrysogenum
complex. Finally, we detected a greater proportion of fungal
conidia on the Underground compared to outdoor sample
sites, and found that the proportions of Penicillium species
present varied between Underground lines.