Investigation of optimum conditions for the growth of Fusarium solani EGY1 causing root rot of guar (Cyamopsis tetragonoloba L.).

Guar gum (Galactomannan) is extracted from Guar (Cluster bean), which is extensively used in petroleum, food and pharmaceutical industry. Root rot of guaris caused by Fusarium solani EGY1 under Punjab, having sub-tropical climatic conditions. This study was undertaken to evaluate different culture media, grain substrates (sorghum, maize, cowpea, guar and pearl millet), temperatures (20, 25, 30, 35oC), pH levels (5.0, 6.0, 7.0, 8.0),light and darkness for the identification of optimum conditions for the growth and sporulation of the fungus. Czapek’s dox mediawas found to be best for growth (84.65 mm) and sporulation (1.8 x 104microconidia and 3.0 x 104 macro conidia) of fungus. For mass multiplication of the fungus, sorghum grains proved to be the best substrate. The fungus showed maximum radial growth at temperature of 25oC (84.36 mm) and pH of 6.0 (84.43 mm) whereas sporulation was highest at 30oC(2.0 x 104 microconidia and 3.2 x 104 macroconidia) and pH of 8.0 (1.8 x 104 microconidia and3.1 x 104macroconidia) respectively. Continuous light favoured radial growth (84.62 mm) whereas sporulation (1.8 x 104microconidia and 3.1 x 104macroconidia) was favoured by darkness. [ABSTRACT FROM AUTHOR]