Simple colorimetric method for detecting degenerate strains of the cultivated basidiomycete Flammulina velutipes (Enokitake).

Degeneration of cultivated strains of Flammulina velutipes is a serious problem. We developed a simple colorimetric method to detect degenerate strains by using a liquid medium supplemented with bromothymol blue and lactose. The ability of a strain to develop normal mushrooms could be determined by the color of the medium.