Effect of Temperature on Growth and Respiration of Ectotrophic Mycorrhizal Fungi

Abstract

with those of other colors, the per cent of ectotrophic mycorrhizae formed by Cenococcum graniforme (Sow.) Ferd. & Winge on Pinus virginiana Mill. has been shown to increase as moisture decreases in soils (Palmer 1954, Worley and Hacskaylo 1959). Whether or not temperature may effect or determine the fungus component in the ectotrophic mycorrhiza and the survival, spread, and activity of such soil fungi is unknown. The variable optima and ranges of such fungi, mostly European, that have been studied in pure culture (Melin 1925, Mikola 1948, Moser, 1956, 1961, Norkrans 1950), indicate that responses to temperature may limit their distribution and activity and therefore their performance in form? ing ectotrophic mycorrhizae with particular species of trees. Many mycorrhizal fungi cannot be isolated in pure culture from mycorrhizae, by germination of basidiospores, or from sporophore tissue transplants. The viability of a large number of those which can be cultured declines during subsequent subculturing. Since many of the Hymenomycetous fungi do not lyophilize or freeze-dry with predictable success, storage of isolates requires constant subculturing and often results in decline or loss of isolates about which a knowledge of genetic composition and physiological performance exists. To better predict competitive performance in the field or in pot culture after inoculation, to successfully isolate in vitro, to reduce decline