Genetic Variability of Canadian Populations of the Sapstain Fungus Ophiostoma piceae

ABSTRACT Genetic diversity was studied in seven Canadian populations of Ophiostoma piceae, the most prevalent sapstain fungus in Canadian softwoods. A total of 239 single-spore isolates were recovered following a systematic survey of sapstain fungi in logs and lumber at seven selected sawmills in six Canadian provinces (British Columbia, Alberta, Saskatchewan, Ontario, Quebec, and New Brunswick). Sampling was carried out on five commercially important softwood species: balsam fir (Abies balsamea), white spruce (Picea glauca), black spruce (Picea mariana), jack pine (Pinus banksiana), and lodgepole pine (Pinus con-torta var. latifolia). The A and B mating types occurred at equal frequency (MAT A/ MAT B = 1.00:1.13) over all populations. Pseudo-allelic frequencies were estimated at each of 24 putative genetic loci by scoring for presence or absence of random amplified polymorphic DNA fragments generated by five primers. A total of 237 haplotypes were found among the 239 isolates, revealing a high level of g...