Canadian Forest Service Publications
Assessment of the genetic variability of Chondrostereum purpureum (Abstract) 1996. Ramsfield, T.D.; Becker, E.M.; Rathlef, S.; Tang, Y.; Vrain, T.C.; Shamoun, S.F.; Hintz, W.E. Page 105 (Vol. 18(1)) in Canadian Journal of Plant Pathology, Proceedings: British Columbia Regional Meeting, The Canadian Phytopathological Society. October 23-24, 1995, Cowichan Lake, British Columbia. Canadian Phytopathological Society, Ottawa.
Issued by: Pacific Forestry Centre
Catalog ID: 4599
CFS Availability: Order paper copy (free)
The genetic variation of 111 isolates of the biocontrol agent Chondrostereum purpureum, collected from Europe, New Zealand, and North America, was assessed by analysis of ribosomal DNA (rDNA). The rDNA repeat of one isolate of C. purpureum was cloned into the Lambda vector EMBL-3, and restriction mapped by probing with cloned rDNA. With PCR, it was determined that the 5S gene was transcribed in the same direction as the 26S gene. The large nontranscribed spacer region of the rDNA was amplified by PCR and analyzed by restriction fragment length polymorphisms. Three nuclear type patterns were identified using the restriction endonuclease Hae III. Nuclear type I was found in North American, European and New Zealand isolates. Nuclear type II was detected in isolates collected from North America and nuclear type III was observed in isolates from Europe and New Zealand. Geographic separation is the likely cause of the isolation of nuclear types, allowing identification of isolates from different geographic origins. Gene flow in the North American population was indicated by the observation of two nuclear type patterns, both found in the east and west. Nuclear type I was the predominant nuclear type in eastern North America indicated by a frequency of 0.66 and nuclear type II occurred with a frequency of 0.90 in western North America. The distribution of nuclear type patterns in North America indicates that gene flow is occurring across the continent but that geographic separation has caused nuclear types to be predominant in separated areas.