Abstract
In the present paper the writers described the results of experiments on the relation between the pathogenicity of thirty eight isolates of Pellicularia filamentosa and free amino acids as well as sugars produced in mycelium or in culture solution.
In culture solution and in mycelium, twelve kinds of free amino acids were detected by the method of paperchromatography. Lysine and methionine were found only in mycelium. Many isolates having an ability to produce alanine, threonine, leucine and undetermined amino acid (Rf=0.42) in mycelium and undetermined amino acid (Rf=0.42) in culture solution showed a high pathogenicity to cucumber seedlings.
Seven kinds of sugars were formed in culture solution and in mycelium. Some of non-pathogenic isolates did not produce undetermined sugar (Rf=0.43) in culture solution and sucrose in mycelium, but produced fructose in mycelium. Amino acids and sugars produced in mycelium were not always identical with those produced in culture solution.
Judging from these results, it may be difficult to divide P. filamentosa clearly into two biological forms, solani and sasakii.
