MYCORRHIZAL FUNGI OF PINUS-RADIATA IN NEW-ZEALAND

Mycorrhizal fungi of a timber species, Pinus radiata D. Don, exotic to New Zealand were isolated. Two isolation methods were used, and root washing without surface sterilization was found to produce a higher proportion of mycorrhizal fungi. Mycorrhizal roots were plated out on Hagem medium and from 7000 pieces 32% yielded Rhizopogon spp; 3% gave rise to Amanita muscaria (L. ex Fr.) S.F. Gray, Hebeloma crustuliniforme (Bull. ex St. Am.) Quél., Suillus spp, Thelephora terrestris Ehrh. ex Fr., and unidentified basidiomycetes; 14% yielded dark sterile mycelia; 19% were sporing Fungi Imperfecti presumed to be contaminants; and 32% remained free of fungal outgrowth. Some of the fungi commonly occurring in P. radiata stands, such as Laccaria laccata (Scop. ex Fr.) Berk. & Br. and Scleroderma verrucosum Vaill. ex Pers. and generally supposed to be mycorrhizal associates of this tree species, were not isolated even though they grow well on the media used for isolation. Mycorrhizas were synthesized on P. radiata seedlings by 16 basidiomycete fungi but under the test conditions Boletus piperatus (Bull. ex Fr.) O. Kuntze and Inocyhe sp., commonly assumed to be mycorrhiza formers on this tree species, did not form mycorrhizas. The results indicate Rhizopogon spp are a major component of mycorrhiza formers isolated from P. radiata in New Zealand. © 1979.