Effect of various carbon and nitrogen sources on the growth and sporulation ofMicroxyphiella hibiscifolia

The carbon and nitrogen nutrition ofMicroxyphiella hibiscifolia Bat., Nasc., and Cif., isolated from the leaves of cotton (Gossypium hirsutum L.), was studied at 28° C for 14 days at pH 4·0. Out of forty-one carbon compounds tested, the pathogen showed excellent growth on dextrose, sucrose, starch, raffinose and maltose; good on inulin; fair on melibiose and galactose; and poor or no growth on rest of the carbon compounds. The pathogen showed excellent sporulation on all the carbohydrates, in general. Out of thirty-three nitrogen compounds tested, the pathogen showed excellent growth on peptone, asparagine, proline, ammonium oxalate, yeast extract, ammonium phosphate, ammonium sulphate; good on ammonium chloride, serine, ammonium nitrate, urea, sodium nitrate, potassium nitrate, histidine mono HCl and histidine di HCl; fair on glutamic acid, lysine mono HCl, arginine mono HCl, threonine, nor-valine and glycine; and poor or no growth on rest of the nitrogen compounds. The pathogen showed excellent or good sporulation, in general, on all the nitrogen compounds. The utilisation of potassium nitrite was conditioned by the pH of the medium.