Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Rapid differentiation of degenerate commercial cultivars of Flammulina velutipes.

Abstract

Three Flammulina velutipes cultivars, designated KW, YH and YQ, originally derived from the same source strain and adopted individually by three different companies for commercial cultivation, exhibited different degrees of degeneration manifested by the delayed formation of primordia (from five to 30 days) or the inability to form fruit bodies. Following subculture from either stock culture slants or cultivation bags on to potato dextrose agar, each source gave rise to several different morphological clones. In some cases, antagonistic reactions were observed among isolates obtained by subculture from a single cultivation bag. Isolates exhibited differing capacities to decolorize LBL liquid medium (pH 7.0) consisting of (/L) 200 g potato extract, 20 g lactose, 2 g NH4NO3, 1.5 g KH2PO4, 0.5 g MgSO4.7H2O and 0.06 g bromothymol blue, and this decolorization ability was inversely related to the degree of strain degeneration. We propose that decolorization of LBL medium combined with colony morphology can be employed by commercial mushroom enterprises to identify degenerate F. velutipes cultivars.