Effect of nitrogen nutrition on growth and sporulation of some pathogenic fungi

Effect of twenty-eight different nitrogen compounds on dry weight and sporulation of Glœosporium musarum isolated from bananas, Glœosporium papayœ and Colletotrichum papayœ isolated from papayas, was studied in liquid cultures. There was no growth of the three fungi on nitrites of sodium and potassium as well as in complete absence of nitrogen from the medium. All nitrates (except NH4NO3) and majority of organic compounds supported good growth while ammonium salts of inorganic acids and thiourea supported significantly poor growth of all the three fungi. Results also indicate that the source of nitrogen in the medium exerts dominating influence on the sporulation. d-alanine, urea, acetamide and all nitrates (except NH4NO3) induced good sporulation. Most of the ammonium salts, glycine, glutamic acid, valine, methionine, l-phenyl-alanine, l-leucine, l-aspartic acid and thiourea supported poor to fair sporulation or completely checked it. The number as well as the presence or absence of setæ of C. papayœ was controlled by the nature of the nitrogen added to the basal medium