Isolation and Characterization of Monokaryotic Strains of Lentinula edodes Showing Higher Fruiting Rate and Better Fruiting Body Production

The effects of monokaryotic strains on fruiting body formation of Lentinula edodes were examined through mating and cultivation of the mated dikaryotic mycelia in sawdust medium. To accomplish this, monokaryotic strains of L. edodes were isolated from basidiospores of the commercial dikaryotic strains, Chamaram (Cham) and Sanjo701 (SJ701). A total of 703 matings (538 self-matings and 165 outcrosses) were performed, which generated 133 self-mates and 84 outcross mates. The mating rate was 25% and 50% for self-mating and outcross, respectively. The bipolarity of the outcross indicated the multi-allelic nature of the mating type genes. The mating was only dependent on the A mating type locus, while the B locus showed no effect, implying that the B locus is multi-allelic. Next, 145 selected dikaryotic mates were cultivated in sawdust medium. The self-mated dikaryotic progenies showed 51.3% and 69.5% fruiting rates for Cham and SJ701, respectively, while the fruiting rate of the outcross mates was 63.2%. The dikaryotic mates generated by mating with one of the monokaryotic strains, including A20, B2, E1, and E3, showed good fruiting performance and tended to yield high fruiting body production, while many of the monokaryotic strains failed to form fruiting bodies. Overall, these findings suggest that certain monokaryotic strains have traits enabling better mating and fruiting.