Spore Germination, Homing Reaction, and Intersterility Groups in Laccaria Laccata (Agaricales)

Spore germination was induced in 29 of 30 collections from different basidiocarps of Lacearia laccata by placing the spores on a charcoal-dusted agar medium containing 0.2% peptone, on the surface of which a mycelium of L. laccata was growing. Preserved at 4 C the spores maintained their viability for 2 to 3 months; at - 18 C they were viable for about 4 months. Growing hyphae of L. laccata showed a typical homing response towards germinating spores, the eventual conjunction between the hyphal tip cell and the spore leading either to a lethal or to a non-lethal reaction. Mating tests with single-spore mycelia from different stocks, i.e., from spores derived from different basidiocarps, showed that the 14 tested stocks represented four intersterile groups.