INOCULATION OF CONTAINERIZED PSEUDOTSUGA-MENZIESII AND PINUS-PINASTERSEEDLINGS WITH SPORES OF 5 SPECIES OF ECTOMYCORRHIZAL FUNGI

Container-grown Pseudotsuga menziesii and Pinus pinaster seedlings wer e inoculated with water suspensions of spores of five ectomycorrhizal fungi commonly found in northeastern Spain. Pseudotsuga menziesii seed lings were inoculated with basidiospores of Melanogaster ambiguus, or Rhizopogon subareolatus, or with ascospores of Tuber maculatum. Pinus pinaster seedlings were inoculated with basidiospores of Melanogaster ambiguus, Rhizopogon roseolus or Scleroderma citrinum. The spore conce ntrations were 10(2)-10(7) spores per seedling for Melanogaster ambigu us (in Pseudotsuga menziesii) and Rhizopogon subareolatus, 10(3)-10(7) for Melanogaster ambiguus (in Pinus pinaster), Rhizopogon roseolus, a nd Scleroderma citrinum, and 10(2)-10(4) for Tuber maculatum. Melanoga ster ambiguus colonized more short roots in a larger proportion of pla nts at 10(7) spores per seedling than at any other rate. The highest c olonization by Rhizopogon subareolatus was obtained at 10(4) spores pe r seedling and higher, and all inoculated plants became infected at 10 (6) spores per seedling and higher. Tuber maculatum colonized a high p ercentage of short roots at all rates tested; the proportion of infect ed plants was over 80% at 10(3)-10(4) spores per plant, decreasing to 50% at 10(2) spores per plant. Rhizopogon roseolus colonized the highe st number of short roots on nearly all the inoculated plants when appl ied at 10(5) spores per seedling and higher. Scleroderma citrinum colo nized a high percentage of short roots on all inoculated plants when a pplied at 10(5) spores per seedling and higher. The abundance of sporo carps of Melanogaster ambiguus, Rhizopogon subareolatus, Rhizopogon ro seolus and Scleroderma citrinum and their colonization ability at rela tively low rates allows these spores to be used as ectomycorrhizal ino cula on a large scale.