Studying the activity of Chenopodium album seed extracts and Fusarium sambucinum culture liquid against several plant pathogenic fungi

Plant extracts and microbial culture liquids contain a great number of bioactive substances, including potential biofungicides, which are effective against plant deseases. Screening of extracts and cultural filtrates for ability to suppress several pathogenic fungi that damage various agricultural plants can result in discovery of new compounds with a broad range of fungicidal activity. This work is the first report on in vitro testing the activity of plant extracts, which obtained by serial extractions of Chenopodium album seeds with hexane followed by ethyl acetate and then with ethanol, and also Fusarium sambucinum culture liquid filtrate (CLF), against six widespread fungi ( Alternaria alternata, A. dauci, A. radicina, Bipolaris sorokiniana, Septoria tritici, Stagonospora nodorum ) that are strongly pathogenic for several economically important crops. These fungi were found to demonstrate different sensitivity to CLF and seed extracts. Thus, CLFs with the standard level of activity against Stagonospora nodorum and A. radicina (effective dilutions up to 1:200 и 1:5, respectively) fully inhibited spore germination of all pathogens except B. sorokiniana, saving their antifugal activity to dilutions 1:5 (for A. dauci ) or 1:50 (for Septoria tritici ). Seed extracts possessed no toxicity against Stagonospora nodorum, Septoria tritici, A. dauci and A. radicina, but some of them reduced A. alternata and B. sorokiniana spore germination. For instance, after seed extraction with hexane followed by ethyl acetate, the number of germinated B. sorokiniana spores decreased by 66 % as compared to control. Hyphae of spores germinated in diluted CLF were morphologically defective and much shorter than control ones. Besides, a significant growth retardation of Stagonospora nodorum, Septoria tritici and B. sorokiniana mycelia was observed on agar media supplemented with CLF (100 μg/ml). Collectively, these results suggest that further research of CFL and the seed extracts can result in identification of anifungal metabolites, which could be promising as biofungicides against leaf and glume bloches of wheat, spot blotch or common root rot of other cereals, and Alternaria diseases of carrot.