VIEW ARTICLE

Physiology and Biochemistry

Nutrition and Respiration of Basidiospores and Mycelium of Pisolithus tinctorius. Willard A. Taber, Professor, Department of Biology and Department of Plant Sciences, Texas Agricultural Experiment Station, Texas A&M University, College Station 77843; Ruth A. Taber, research scientist, Department of Biology and Department of Plant Sciences, Texas Agricultural Experiment Station, Texas A&M University, College Station 77843. Phytopathology 72:316-322. Accepted for publication 22 June 1981. Copyright 1982 The American Phytopathological Society. DOI: 10.1094/Phyto-72-316.

Basidiospores of the mycorrhizal puffball, Pisolithus tinctorius, germinate rarely if at all in vitro, and this may be due at least in part to an inability to respire significantly until certain specific conditions are met. A low rate of respiration was detected by gas exchange and production of ¹⁴C-CO₂ when approximately 15 mg of spores wetted with Tween-80 solution and suspended in phosphate buffer were exposed to ¹⁴C-glucose for extended periods of time in the Warburg respirometer. Respiration was not stimulated by the presence of B vitamins, trace elements (including citrated iron), a mixture of vitamins and trace elements, or yeast extract. Respiration of exogenous glucose was low and was not accompanied by a marked increase in rate of respiration over endogenous respiration. Respiration was partially inhibited by a mixture of sodium azide and iodoacetate. To test the possibility that P. tinctorius mycelium might possess either the exotic growth requirements or limited carbohydrate metabolism of some other basidiomycetous mycorrhizal fungi, a study of nutritional requirements and growth patterns of mycelial cultures was undertaken. Mycelium respired glucose, mannose, mannitol, cellobiose, and trehalose, but grew well only on glucose and cellobiose of the several carbon sources examined. Growth occurred in cultures with nonionized succinic acid as the sole carbon source, but not on either ionized or nonionized acetic acid. Spores and mycelium both contained lipids and a similar array of nonreducing polyhydroxy compounds; the latter probably consisted of polyols and a disaccharide. One or more of these constituents may be the substrates for endogenous respiration.