Influence of rutin on fruiting of Hericium coralloides, Polyporus umbellatus , and Flammulina velutipes .

We studied the effect of rutin on mycelial growth and fruiting of Hericium coralloides, Polyporus umbellatus , and Flammulina velutipes on sunflower husks and on agar nutrient media. On sunflower husks, rutin (300 mg/30 g husk) inhibits the mycelial growth of H. coralloides , but the formation of fruiting bodies of the fungus occurs 3 weeks earlier than on the substrate, where rutin was not used. In half of the cases with rutin, we observed two waves of fungus fruiting. The weight of fruiting bodies formed on sunflower husks with rutin was 2.5 times greater than the weight of fruiting bodies formed on sunflower husks without rutin. For P. umbellatus and F. velutipes , adding rutin (300 mg/30 g husk) confers no net benefit. On wort agar (WA), the addition of rutin at concentrations of 50, 100, 200, and 300 mg per Petri dish inhibits the mycelial growth of H. coralloides but stimulates the rapid emergence of the fungus fruiting bodies rudiments. For F. velutipes on WA, rutin accelerates the complete overgrowth of the fungus on the Petri dish twice as fast, but it is not effective for accelerating fruiting. Rutin does not stimulate the formation sclerotia of P. umbellatus . Due to the fact that rutin is a stimulant of fruiting bodies only for H. coralloides , we believe that the initiating mechanism causing fungal fruiting is not isolated only to rutin. However, it may be more widely effective in influencing growth in mycelium than is shown in this study due to a limited number of strains. Production of metabolites as a result of secondary synthesis need to be tested as do more strains/species from a diverse group of Agaricomycetes.