DNA sequence variation supports multiple host-specialised taxa in the Peronospora viciae complex (Chromista: Peronosporales)
Cunnington, James H.
The Peronospora viciae complex on Vicia and Pisum has been treated as a single species or a group of up to six different species by various authors over the last 80 years. Ribosomal DNA ITS1 sequences from specimens on a range of Vicia species and Pisum sativum, collected between 1960 and 2002, were found to have small sequence differences correlating with the host species. These support the separation of P. viciae, P. mayorii, P. ervi and P. narbonensis. Specimens on Pisum sativum and V. sepium had identical ITS sequences, but host range differences reported in the literature support two different taxa, i.e. Peronospora pisi and P. sepium. The fungus infecting Vicia tetrasperma was found to be an undescribed species.