稲小粒菌核病菌の生理 : 窒素代謝に就いて

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In the present paper, the results of a study on the nitrogen metabolism of the causal fungi of stem rot of rice plant, Leptosphaeria salvini Catt. and Helminthosporium sigmoideum Cav. irregulare Cralley et Tullis. Both fungi were cultured in liquid media at 25℃ for 3 weeks. The nutrient solutions conntained one of the following substances respectively, as a nitrogen source: KNO_3, (NH_4)_2SO_4, (NH_4)_2HPO_3, NH_4NO_3, NaNO_2, urea and peptone. Decoction of straws and leaves of rice plant was added to the nutrient solution at a rate of 10%, as growth promoting substance. Both fungi could not utilize NO_2-N, but absorb NH_3-N, NO_3-N, urea and peptone. Growth of the fungi was checked by NO_2-N. Difference in growth between the two fungi was observed according to the kinds of nitrogen source. Leptosphaeria-fungus could grow better than Helminthosporium-fungus in the presence of(NH_4)_2SO_4, NH_4NO_3 and peptone, while Helminthosporium preferred (NH_4)_2HPO_4. The two fungi grew vigorously in the presence of nitrogeous substances which have not decreased the pH of the nutrient solution. Above all, peptone gave the best growth of them. When NH_3-N and NO_3-N co-exit, both fungi absorb NH_3-N selectively and quickly, and absorb NO_3-N later. Helminthosporium-fungus begins to absorb and utilize NO_3-N earlier than Leptosphaeria-fungus.
日本植物病理学会の論文
1955-03-30