CYTOLOGY OF THE LIFE-CYCLE OF MORCHELLA

Various stages of the morel life-cycle are studied cytologically. Photomicrographic evidence demonstrates that the average number of nuclei per cellular compartment in vegetative hyphae of Morchella is 10–15 and that hyphal fusions are quite frequent. The resting structures, the sclerotia, are actually pseudosclerotia which form from the repeated branching and enlargement of terminal hyphae from either primary (homokaryotic) or secondary (heterokaryotic) hyphae. Photomicrographs also depict the development of fruiting body primordia. Photomicrographs of ascus development demonstrate autogamy rather than de novo heterokaryon formation by hyphal fusion in the subhymenial layer of the fruiting body. For the first time a comprehensive life-cycle diagram of the morel is introduced. © 1990, British Mycological Society. All rights reserved.