Preliminary studies on mating and improved strain selection in the tropical culinary-medicinal mushroom Lentinus squarrosulus Mont. (Agaricomycetideae)

Lentinus squarrosulus Mont. is an important tropical edible and medicinal mushroom distributed across Sub-Saharan Africa and most parts of Asia. Intrastock mating study was performed using single spore isolates (ssi) from a wild strain (MBFBL 201). Mycelia growth and morphology characterization indicated that milled corn straw agar (CSA) medium best supports mycelia growth compared to two other media: potato dextrose agar (PDA) and yeast peptone soluble starch agar (YPSS). The results from ssi pairings and analysis confirmed a tetrapolar mating system for L. squarrosulus. Further characterization of the resulting dikaryons indicated that the growth rate of the parent monokaryons does not affect the growth rate of the resulting dikaryon. Primordial formation in the resulting dikaryons with the fastest growth rate was 12 days after inoculation. Under similar conditions, MBFBL 201 and another wild strain, MBFBL 269, produced primordia after 28 and 32 days, respectively, indicating that intrastock breeding could be an effective method for obtaining improved strains of L. squarrosulus. Further characterization to test growth and performance in order to obtain high-yield strains for use in commercial cultivation is ongoing.