. Cryptogamic plants of the USSR. (Flora sporovykh rastenii SSSR). Plants. Experiments with germinating spores of rust fungi were carried out in order to determine the type of action of the host plant in the initial phases of the infection. K. Sergeeva (1942) and V. Kuprewicz (1947) established the inhibiting action of aqueous extracts from tissues immune to plant parasites. In a number of cases the spores were destroyed in the presence of aqueous extracts from leaves of unusual hosts. In the experiments of V. Zemit (1947), seeds of different kinds of flax were germinated in water
. Cryptogamic plants of the USSR. (Flora sporovykh rastenii SSSR). Plants. Experiments with germinating spores of rust fungi were carried out in order to determine the type of action of the host plant in the initial phases of the infection. K. Sergeeva (1942) and V. Kuprewicz (1947) established the inhibiting action of aqueous extracts from tissues immune to plant parasites. In a number of cases the spores were destroyed in the presence of aqueous extracts from leaves of unusual hosts. In the experiments of V. Zemit (1947), seeds of different kinds of flax were germinated in water extracts from tissues infected by Melampsora lini-usitatissimi. The seeds of the resistant kinds germinated, but those of the sensitive kind did not germinate. The author recommends using the method of seed germination in aqueous extracts from affected tissues of vegetative organs to determine the resistance of the kinds of common flax to rust fungi. In our investigations (Kuprewicz, 1940, 1945, 1947) the enzymatic action of rust fungi on substrates was established. As shown by many experiments, enzymatic activity in rust fungi and in other obligate parasites is con- siderably less than in saprophytes and in facultative parasites. Many extracellular enzymes common to saprophytic fungi were not found in germinating spores of rust fungi. A large number of works has been devoted to study of the racial com- position of the rust fungi. Thus, investigations of the racial composition of Puccinia graminis Pers. were carried out by D. Teterevnikova-Babayan (1926, 1928), by A. Barmenkov (1939), and by some other authors. More numerous were the works on the racial composition of brown leaf rust of wheat, Puccinia triticina Erikss.; A. Bukhgeim and M. Lisitsina (1934) investigated the racial composition of P. triticina in the central districts of 34. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and a
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Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectplants
