Presence and distribution of double-stranded RNA elements in the white root rot fungus Rosellinia necatrix

Double-stranded (ds)RNA of various types was detected in 65 (21.8%) of 298 isolates from vegetative hyphae of Rosellinia necatrix by electrophoresis, but dsRNA was not detected from 39 ascosporic isolates. There were 45 distinct dsRNA profiles in the 65 isolates: they varied in the number of electrophoretic bands from 1 to 12 and in size from less than 1000 bp to more than 10 kbp. Each dsRNA profile was unique to each locality. dsRNAs having the same profiles were restricted to isolates of the same mycelial compatibility groups (MCG) from the same trees, with an exception where different profiles were detected in different isolates of the same MCGs. Received: May 7, 2001 / Accepted: September 5, 2001