The effect of carbon and nitrogen sources on the formation of sclerotia in Morchella spp.

Abstract

Cultural assays were used to compare the effect of various carbon (C) and nitrogen (N) sources on in vitro sclerotial formation and development, specifically in mycelial cultures of black and yellow morels (Morchella elata and Morchella crassipes, respectively). While different C and N sources supported abundant mycelia growth, these nutritional parameters also influenced sclerotial formation. Carbon sources such as ribose, cellobiose, galactose, xylose, sucrose and mannitol produced many (18–125) large-sized (diameter 0.16–0.43 cm) and cream-colored sclerotia in M. crassipes; in M. elata, small-sized (diameter 0.16–0.28 cm) and brown-pigmented sclerotia were formed in media containing ribose, galactose, sorbose and mannitol. Among the nitrogen sources, sodium nitrate and yeast extract caused both morel species to produce significantly fewer sclerotia (6–24) of significantly smaller size (diameter 0.11–0.27 cm). Carbon sources such as mannitol and ribose and N sources, sodium nitrate and yeast extract produced numerous large-sized sclerotia in morels.