Breeding cold tolerance strain by chemical mutagenesis in Volvariella volvacea

Volvariella volvacea is a mushroom well-adapted to high temperature. It optimally grows at 30–35 °C. To breed cold-tolerant strains to expand cultivation region and season, the basidiospores and gills of V. volvacea were treated with chemical mutagens, ethyl methane sulfonate (EMS) and diethyl sulfate (DES), respectively. Two cold-tolerant strains, strains Em-16 and Em-18, were successfully obtained from EMS mutagenesis of gills through 0 °C screening, colony morphology screening and fruiting screening. The biological efficiencies of Em-16 and Em-18 strains were 24.55% and 23.61% in the first flush at 27 °C and their biological efficiencies were 46.1% and 40.5% higher than the control strain V41, respectively. Their fruiting bodies had a longer storage life at 16 °C, compared with the control strain V41. Amplified fragment length polymorphism analysis shows that the strains Em-16 and Em-18 are new strains.

► EMS and DES mutagenesis of basidiospores and gills for breeding of Volvariella volvacea.
► Established 0 °C screening system to select candidate mutants.
► Applied stepwise 0 °C, morphology and fruiting screening to isolate desired mutants.
► Obtained two cold-tolerant V. volvacea strains by MES mutagenesis of gills.
► Applied AFLP to identify the desired new strains.