LIGHT-STIMULATIVE EFFECTS ON THE CULTIVATION OF EDIBLE MUSHROOMS BY USING BLUE LED

Abstract

Fruiting body formation of mushrooms is closely involved with “light”, which seriously affects their productivities in both quality and quantity. Primordium formation in several cultivable mushrooms requires light and seldom occurs under continuous darkness. Light also induces the development of fruiting bodies including stipe elongation and cap formation. LED (light emitting diode) has many advantages over current lightings and has been gradually replaced everywhere in recent years. These prompted us to develop more effective lightings in the cultivation of mushrooms, by using blue LED. The cultivations of popular mushrooms eaten in Japan (Lentinula edodes, Flammulina velutipes, Hypsizygus marmoreus, Grifola frondosa, Pholiota nameko and Pleurotus eryngii) were carried out with mushroom blocks (sawdust substrate media) under several lighting conditions. The exposure to continuous light by blue LED during vegetatively growing mycelial stage in L. edodes brought higher productivity and quantity of fruiting bodies than using usual white fluorescent lamps. The characteristic fruiting bodies of P. nameko and P. eryngii were efficiently obtained by the irradiation with blue LED during fruiting body formation, and high intensity at the primordial stage in G. frondosa caused high productivity of fruiting bodies, which were derived from highly induced primordia. Moreover, the surface exfoliation of cultivated mushroom-blocks, a serious issue especially found in F. velutipes, was successfully avoided by the exposure to blue LED at primordium formation. We present that several conditions of light environment artificially controlled by LED, a new valuable device, provide us more efficient production of cultivable mushrooms.