DEVELOPMENT OF MYCORRHIZAE, EXTRAMATRICAL MYCELIUM AND SCLEROTIA ON PINUS STROBUS SEEDLINGS

Abstract

SUMMARYOn Pinus strobus seedlings cultured in growth pouches successful ectomycorrhiza formation took place upon inoculation with Pisolithus tinctorius, Cenococcum geophitum, Suillus granulatus, Suillus tomentosus, Paxillus involutus, Hebeloma cylindrosporum and Thelephora terrestris.Under the conditions used ectomycorrhizae formed within 2 weeks and some of them, P. tinctorius, P. involutus and T. terrestris, developed mantles and Hartig nets in less than 5 days. Mycelial strand formation took place around the root system of P. strobus 2 weeks after inoculation with P. tinctorius. Sampling on the 93rd day revealed no difference in ectomycorrhizal formation or the development of mycelial strands and sclerotia hetween root systems that were or were not illuminated. However, low light intensities on the aerial parts of the seedlings reduced the mycelial strands and sclerotia formation.Variation of nitrogen and phosphorus concentration added to the pouches were also studied.

Effects of liming on ectomycorrhizal fungi infecting Pinus sylvestris L.

“…The plant nitrogen concentration at optimal infection were 19 and 16 % for the black spruce and the jack pine seedlings respectively. Piche & Fortin (1982) also recorded this phenomenon with Pinus strobus seedlings, but the plant N concentration in their study never exceeded 1-14% (compared to the lowest N concentration of 2-2% in our experiment). The increased nitrogen availability discussed above may consequently also explain the decreased mycorrhizal infection that was observed.…”

Release of a reducing substance by the ectomycorrhizal fungi Pisolithus tinctorius and Paxillus involutus

“…Regions within mycorrhizal root systems where acidification was occurring were demonstrated by embedding root systems of intact plants in an agar medium containing Pich6 and Fortin (1982) nutrient solution, 0.05% bromocresol purple and 0.75% agar (initial pH 6.5). Root systems were incubated in fresh Pich6 and Fortin nutrient solution for 30 min prior to embedding in the cooling agar solution (ca 37°C) in 20-cm-diameter Petri dishes.…”

MORPHOLOGICAL FEATURES OF SYNTHESIZED ECTOMYCORRHIZAE OF ALNUS CRISP A AND A. RUGOSA*

“…Depending upon the intensity of nodulation, as it affects directly the growth of the alder, the seedlings were inoculated with potential mycorrhizal fungi between the 45th and 70th day after their transfer to the pouches. The fungi were previously grown on MNM agar medium (Marx and Bryan, 1975) and introduced as plugs into the pouches (Piche and Fortin, 1982). Simultaneously 20 x 5 x 5 mm pieces of foam were introduced into the pouches to maintain an air space between the front of the pouch and the pad.…”

“…The ectomycorrhizae were fixed in glutaraldehyde and embedded in glycol methacrylate (Piche and Fortin, 1982). This method permitted detailed observation of the structure of the tissue, but was not suitable for cytoplasmic or histochemical studies of the alder roots.…”