Abstract
The sclerotial formation of Sclerotium rolfsii was stimulated or inhibited by various amino acids. Sulfur-containing amino acids were always inhibitive toward the formation. Despite the structural resemblance between serine and cysteine, the effect on formation is quite different. This fact may possibly indicate the inhibitory effect of S or SH toward sclerotium development. The process of sclerotium formation was divided into main five stages: hyphal branching, aggregation and network formation, initials formation, whitish sclerotium formation and maturation. Inhibition by sulfur-containing amino acids appeared more distinctly when treatment was conducted at the early stage of sclerotium development. The mechanism of inhibition is briefly discussed.
