Successful cultivation of black morel, Morchella sp. in Japan.

True morels (Morchella spp.) are economically important edible fungi cultivated mainly in China. Japan is one of the top importers of morels, but there are no reports on the distribution of major cultivated species. To investigate the possibility of black morel cultivation in Japan, phylogenetic analysis, mating-type analysis, and field cultivation tests were conducted using domestically collected strains. A total of 172 strains were isolated from the spores of wild ascomata collected from 15 locations. Mating-type analysis for 118 strains revealed 28 strains had only MAT1-1-1, 40 strains had only MAT1-2-1, and 48 strains had both MAT genes. Seven strains were inoculated in March 2020 at the field cultivation test site. Mycelial growth and conidial layer formation were observed within a month. Ascomata were observed in April 2021 for one of the tested strains. Phylogenetic analysis revealed that both the observed ascomata and fruited strains were Morchella sp. Mel-21, which is one of the cultivated species in China. Moreover, no antagonism was observed in the somatic incompatibility test between strains isolated from observed ascomata and spawn strain. These results suggest that the ascomata originated in the inoculated spawn, a finding that will contribute to commercial morel cultivation in Japan.