Determination of Toxicity of some Fungal Metabolites on Seed Germination and Pigment Leaching

In present investigation, eighteen fungi were isolated on Potato Dextrose Agar and Rose Bengal Agar medium from abnormal soybean seeds. Out of these eighteen fungi, ten dominant fungi were selected to study the toxic potentialities of culture filtrate of these ten fungi on oilseeds germination, pigment leaching i.e. chlorophyll of spinach and betalain of beet root.  Maximum loss of chlorophylls was caused due to toxins of Aspergillus niger, Aspergillus flavus and Penicillium notatum. Fusarium oxysporum caused minimum loss of chlorophylls. Aspergillus niger and Alternaria dianthicola was responsible for maximum leaching of betalain pigment while Curvularia lunata causes minimum leaching of pigment.---Seed Pathology and Fungal Biotechnology Laboratory, Department of Botany, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad- 431004(M.S.) India  ---Please Cite This Article As: Rajendra B. Kakde and Ashok M. Chavan. 2010. Determination of Toxicity of some Fungal Metabolites on Seed Germination and Pigment Leaching. J. Ecobiotechnol. 2(6):46-55.Â

Effect of Carbon, Nitrogen, Sulphur, Phosphorus, Antibiotic and Vitamin Sources on Hydrolytic Enzyme Production by Storage Fungi

In present investigation emphasis is given on to screen the lipolytic activity of storage fungi. Abnormal safflower seeds of PBNS-12 and Bhima varieties were collected from Marathwada region of Maharashtra state. Dominant fungi were isolated from abnormal oilseeds on Potato Dextrose Agar (PDA). Total twenty fungi were isolated. Out of that lipase enzyme activity of ten dominant fungi other than Aspergillus sp. was studied by using different nutritional sources like carbon, nitrogen, phosphorus, sulphur, antibiotic and vitamin sources. It was found that carbon sources like fructose and sucrose induces lipase activity while starch, lactose and carboxyl methyl cellulose (CMC) inhibits lipase activity. Nitrogen sources like casein and peptone which are organic forms stimulated maximum lipase enzyme production of storage fungi. Sulphur sources like calcium sulphate and ferrus sulphate reduced the lipase enzyme production by storage fungi while, phosphorus source like di-sodium hydrogen ortho-phosphate, ammonium phosphate and potassium di-hydrogen ortho-phosphate stimulated lipase enzyme production. Antibiotic like ampicillin, norfloxacin and tetracycline reduced the lipase production of storage fungi. Lipase activity of storage fungi was reduced in presence of vitamin source like riboflavin while, folic acid and vitamin C stimulated the lipase enzyme production

Deteriorative changes in oilseeds due to storage fungi and efficacy of botanicals

Improper storage makes the oilseeds vulnerable to storage fungi which deteriorate the stored oilseeds both qualitatively and quantitatively. They bring about the variety of biochemical changes in the suitable conditions. Considering this fact, experiments were undertaken to understand nutritional changes like change in reducing sugar, change in crude fat content and change in crude fiber content of oilseeds due to artificial infestation of storage fungi. It was found that, Alternaria dianthicola, Curvularia lunata, Fusarium oxysporum, Fusarium equiseti, Macrophomina phaseolina and Rhizopus stolonifer causes decrease in reducing sugar of oilseeds. Alternaria dianthicola, Curvularia pellescens, Macrophomina phaseolina, Penicillium digitatum and Penicillium chrysogenum hampered the fat content of oilseeds. Curvularia lunata, Curvularia pellescens, Fusarium oxysporum, Macrophomina phaseolina, Rhizopus stolonifer and Penicillium digitatum increased the fiber content in oilseeds. An attempt was also made to control the seed-borne fungi by using aqueous extract of ten medicinal plants. Aqueous extract of Eucalyptus angophoroides was found to be most fungitoxic