Nutrition of Melampsora lini and Puccinia helianthi

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When uredospores (urediniospores) were used as inoculum, glucose and sucrose supported good colonial growth of Melampsora lini (Ehrenb.) Lév, strain 1 and race 79, both in liquid culture and on solidified agar media. Induction of a high frequency of mycelial initials occurred on mannitol and fructose, but these initials did not develop further on fructose. Cysteine or cystine, but not methionine, in combination with either glutamic acid, aspartic acid, or alanine could substitute for peptone or casamino acids to allow growth of these two isolates. A combination of glutamic acid and cystine provided the best amino acid source for both isolates. Subcultures of established colonies of M. lini could utilize a wider range of carbon compounds, including sucrose, glucose, fructose, mannose, trehalose, raffinose, ribitol, arabitol, mannitol and glycerol. No growth occurred on galactose, dulcitol, acetate, corn oil, soluble starch or glycogen. Amino acids and amides which allowed growth were : alanine, glycine, serine, aspartic acid, asparagine, glutamic acid, glutamine, or arginine, in combination with either cysteine or cystine. Methionine could serve as the sulphur amino acid source providing that the established colonies were ‘conditioned’ first on a medium containing eleven different amino acids. Thiamine and biotin had no effect on the growth of either initial or established colonies of M. lini . Calcium ions stimulated the growth from uredospores of M. lini , strain 1. Growth of Puccinia helianthi Schw., race 1, from uredospores was obtained on a medium containing sucrose, inorganic salts, bovine serum albumin (BSA) and a complex nitrogen source such as peptone, casamino acids or tryptone. Glucose, mannitol, mannose or fructose were effective substitutes for sucrose. Galactose, ribitol, sorbitol and maltose did not support growth. Aspartic acid, glutamic acid, or alanine in combination with cysteine could take the place of the complex nitrogen source. The requirement for BSA was absolute and no substitute for it was found.