title: Nutritional factors determining sclerotial formation of Polyporus umbellatus.
abstract: OBJECTIVE
  To find out which nutritional condition is the determining factor for sclerotial formation of Polyporus umbellatus.
  
  
  RESULTS
  The nutritional requirements of 15 carbohydrates, ten nitrogen compounds, eight vitamins and eight mineral elements were studied for their effects on mycelial growth and sclerotial formation of Polyporus umbellatus using the one-factor-at-a-time method. Only fructose could induce sclerotial formation of P. umbellatus. An additional test indicated that nitrogen source categories influenced sclerotial formation significantly and that peptone was found to be the best for sclerotial production. Through an orthogonal matrix test, the effects of carbon/nitrogen factors on sclerotial formation were found be in the order: fructose > interaction between fructose and peptone > peptone. The optimal concentration for sclerotial formation was determined to be 50.0 g l(-1) fructose and 4.0 g l(-1) peptone.
  
  
  CONCLUSIONS
  Carbon source is the factor determining sclerotial formation of Polyporus umbellatus. Nitrogen source can influence such a morphological transformation significantly. The categories of vitamin and mineral element do not have relationship with the sclerotial formation.
  
  
  CONCLUSIONS
  This study provides the preparatory knowledge for the completely artificial culture of Polyporus umbellatus for its sclerotium.
authors.affiliation: Laboratory of Medicinal Fungi, Institute of Medicinal Plants, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
authors.forename: Y-Y
authors.initials: YY
authors.lastname: Liu
authors.forename: S-x
authors.initials: SX
authors.lastname: Guo
mesh_terms: D050260:Carbohydrate Metabolism; D008903:Minerals / Q000378:metabolism; D025282:Mycelium / Q000254:growth & development* / Q000378:metabolism*; D017672:Nitrogen Compounds / Q000378:metabolism; D010461:Peptones / Q000378:metabolism; D055492:Polyporus / Q000254:growth & development* / Q000378:metabolism*; D014815:Vitamins / Q000378:metabolism
chemical_list: D008903:Minerals; D017672:Nitrogen Compounds; D010461:Peptones; D014815:Vitamins