Chemical Induction of Pyronema Domesticum Apothecia in the Dark

ABSTRACT

Chemical treatment with potassium permanganate, sodium bicarbonate, or potassium bicarbonate induced apothecial formation by Pyronema domesticum in the dark although light is normally required. Three-da old vegetative cultures on Claussen's agar were partially flooded with 0.5 ml of the chemical solution and then incubated in the dark for an additional 4 da. Apothecia were formed only in that part of the culture in contact with the chemical solution. Lysis occurred in some hyphae as a result of this treatment. Apothecia were white or faintly pink, unlike the salmon colored ones that develop in the light. Potassium permanganate and potassium bicarbonate induced well-developed apothecia with mature ascospores. Apothecia formed after sodium bicarbonate treatment were typically incompletely expanded, had poorly developed ascogenous hyphae, and rarely formed asci. Cultures treated at the time of inoculation, or at 1 or 7 da of age with potassium permanganate or sodium bicarbonate formed apothecia in fewer cultures than when treated at 3 da. Treatment with potassium permanganate or sodium bicarbonate did not induce apothecial formation on Claussen's agar containing 3 g amino acids/1 or on potato dextrose agar although apothecia will form on these media under certain light conditions. Negative results were obtained with several other chemicals tested.

Key Words:

• Pyronema
• apothecial development
• light