Studies on the Nutrition of Coprinus lagopus Fr., especially as affecting Fruiting

Growth and fruiting of Coprinus lagopus in pure culture havebeen studied on a medium containing glucose, dl--alanine, mineralsalts and thiamin, and the effects of changes in concentrationof certain components of this medium and of various substitutionsinvestigated. It is demonstrated that fruiting led to withdrawalof materials from the whole of the colony. No evidence was obtainedof the existence of a minimal quantity of substrate for fruitingto take place. The distribution of mature sporophores on a colonywas affected by an internal mechanism. A theory as to its possiblenature is suggested.     

The numbers of viable myxomycete cells in the alimentary tracts of earthworms and in earthworm casts

The numbers of 'plasmodium-forming units' (PFUs) of myxomycetes (mycetozoa or myxogastrids) in worm casts and soil were estimated by a most-probable-number method. Casts contained about five times more PFUs g dry wt˜' than did adjacent non-cast soil. Gut contents contained similar numbers to non-cast soil, but the proportion which was freezing resistant (and presumably in a resting stage) was greater. Numbers of PFUs in incubated worm casts increased rapidly, then fell. This transient increase probably accounts for the generally higher number observed in natural casts. Earthworms may serve as vectors of myxomycetes in soil.     

The Influence of Light and Temperature on Fruiting of Coprinus lagopus Fr. in Pure Culture

Some effects of light and temperature on fruiting of Coprinuslagopus in pure culture are described. Fruiting, which in darknessdid not commence until about the 15th day, was accelerated bycontinuous light or by brief exposures to light between the7th and 13th days of incubation. Very small exposures sufficed,provided they were of a wavelength no longer than that of greenlight, the response being restricted to the area of myceliumactually exposed. In both light and dark a temperature near25° C. was optimal for growth and fruiting.     

The Fine Structure of Conidia of Botryodiplodia ricinicola with Observations on Effects of Chilling

Conidia of Botryodiplodia ricinicola (Saccardo) Petrak havebeen studied, principally by freeze-etch electron microscopy.Freshly harvested conidia have a thin scaly surface layer, freeof rodlets, which covers an otherwise homogeneous-looking wallwhich is continuous with the single centrally-perforate septum.The contours of the plasmalemma are usually smooth. Nuclei andsmall vacuoles are numerous. Hydrophobic fracture faces of theplasmalemma, tonoplasts and nuclear membranes variously revealintra-membrane particles or corresponding depressions or both.Lipid inclusions are small and numerous. Compact orderly stacksof membranes are present, sometimes one in each locule of theconidium. Conidia of a strain insensitive to chilling were seento differ only in respect of the distribution of intra-membraneparticles on fracture faces of tonoplasts. Chilled and chilled-and-soakedconidia of the wild type showed fine-structural differencesfrom untreated conidia, most obviously in respect of the greatersize of some of the lipid inclusions, but also in respect offeatures of the plasmalemma which after chilling contained plasmalemmasomesand, after subsequent immersion for 15 min, showed annular depressions.Also, intra-membrane particles in some membrane systems showedaltered distribution between the two hydrophobic fracture faces.It is concluded that cell lipids and cytoplasmic membrane systemsmay be involved in the previously demonstrated chilling sensitivityof conidia of this species. Botryodiplodia ricinicola, conidia, ultrastructure, chilling effects