Abstract
<i>Lentinula edodes</i> (Berkeley) Pegler (i.e., shiitake mushroom) is one of the most widely produced mushrooms, especially in Asia. However, even though the species’ genome and transcriptome have been analyzed extensively, breeding of the species has continued to rely on traditional mating. Accordingly, the aim of the present study was to apply marker-assisted selection, based on genetic and genomic information, to <i>L. edodes</i> breeding. An L. edodes strain (Mu789) with a glucanase-encoding gene (<i>exg2</i>) mutation was identified using targeting-induced local lesions in genomes (TILLING). The strain produced fruiting bodies with sustained post-harvest gill whiteness and reduced post-harvest glucanase activity, and the <i>exg2</i> mutation-associated phenotype was inherited by the progeny of a cross between Mu789 and the commercial strain, HS715. Backcrossing of the progenies with HS715 yielded strains that exhibited both desirable post-harvest and cultivation traits. When compared to strain HS715, the fruiting bodies of two strains in particular (2520DA and 5624DA) exhibited both maintained post-harvest gill whiteness and reduced post-harvest glucanase activity. Furthermore, the strains had higher agronomic traits, such browning of the mycelial block and cap shape, than strain Mu789. The findings of the present study demonstrate the usefulness of Mu789 as a parent strain in marker-assisted selection-based shiitake breeding programs.
