Responses of agaric fruit-bodies to light and gravity: growth straight downward in response to light from below

Abstract

Fruit-bodies of Agaricales are known to show positive phototropism during the early stage of development, but negative gravitropism at the later stage after the onset of basidiospore formation. However, when exposed to light from below, the fruit-bodies of Tephrocybe tesquorum and Coprinus spp. grew downward through all stages of development, even after the onset of basidiospore formation. Primordium formation, fruit-body development and basidiospore formation were not disturbed under such conditions. In these downward-growing fruit-bodies, gills stood straight upward. In T.tesquorum, caps often became swollen and stipes sometimes became twisted anticlockwise, contrary to those in light from above, while such behaviours were not observed in Coprinus spp.

Responses of lignicolous-agaric fruit-bodies to light and gravity: a study to overview the fruit-body development in hymenomycetes

“…2, I-III). The bags were put into pots which were the same as those used in the previous study (Kaneko and Sagara, 2001). After autoclaving at 120~ for 40 min and cooling to room temperature, the medium was inoculated with 5-15 ml of spawn grown on the MYP agar (IV in Figs.…”

“…Here, we assume that P. ostreatus belongs to the Polyporus Type. Based upon this assumption, we will compare, in Discussion, the Coprinus Type, the Non-Coprinus Type and the Polyporus Type, to overview graviresponses in hymenomycetes, referring to our previous data (Kaneko and Sagara, 2001) and the literature.…”

“…Previously we examined one Non-Coprinus Type species and three Coprinus Type species (Kaneko and Sagara, 2001). Here, we examine two Non-Coprinus Type species and one assumed Polyporus Type species, i.e., Pleurotus ostreatus (Fr.)…”

“…Previously we examined humus-borne epigeous agarics (Kaneko and Sagara, 2001), and here we examine lignicolous, wood-rotting agarics to compare the responses of these two groups to light and gravity. Woodrotting agarics usually fruit on non-horizontal wood-surfaces, whereas epigeous ones usually fruit on horizontal ground-surfaces.…”

“…As a substratum, we previously used raw humus to obtain agaric fruit-bodies in light from below (Kaneko and Sagara, 2001). Here, we use sawdust, since it can as well be set afloat as the raw humus, and thus fruit-bodies emerging from the undersurface of the substratum can be exposed to light from below throughout their development.…”