The utilization of allelopathic plants has been receiving worldwide attention because it could reduce application of herbicides. Buckwheat is one of those plants with a high allelopathic potential. The genetic variability of allelopathic potential has been described in, e.g. rice, lucerne and wheat. The aim of the present work was to evaluate the influence of varieties on the allelopathic potential of common buckwheat. Three varieties of common buckwheat of different origins were tested. Varietal differences were evaluated through biotests with aqueous extracts of both fresh and dried plant parts of buckwheat (leaves, stems, roots). Varietal differences in allelopathic potential of common buckwheat were found in extracts from all plant parts. The strength of the allelopathic potential was dependent upon treatment (fresh or dried material) and conditions within the given year. Rutin, the main flavonoid of buckwheat, probably plays an important function in the allelopathic potential of buckwheat biomass and it is the possible reason of varietal differences.
The aim of this work was to investigate the influence of rutin, the main buckwheat flavonoid, on the growth and germination of selected phytopathogenic fungi —
Alternaria alternata, Botrytis cinerea
. Fungitoxicity of rutin was determined by the germination test using conidial suspensions of a fungi and the radial growth test using agar discs with the maternal fungus mycelium. Effects of rutin on tested fungus species were not toxic. Rutin stimulated formation of germ tubes and conidia of
. Inhibitory effects were found only on prolongation of germ tubes, secondary hyphal branching and the radial growth of
. The effect of rutin was dependent on the concentration especially by
The use of buckwheat as a source of rutin for medicine or food supplement requires a high content of this component in pimary row materials. The study was aimed at the investigation of the influence of stand density and sowing dates on the rutin content in the aboveground parts at the stage of flowering and achenes of two buckwheat species (Fagopyrum esculentum and Fagopyrum tataricum). The rutin content in the aboveground parts of buckwheat was significantly higher in plants sown in mid-May. The sowing date did not influence the rutin content in the achenes. The whole buckwheat plant contained the highest content of rutin in 25 cm rows with a sowing ratio of 200 achenes per square metre. However, the final rutin amount obtained from a buckwheat stand depended on the production of biomass. Common buckwheat provided a higher rutin yield because it produced a higher amount of biomass of inflorescences, the part rich in this flavonoid. Therefore 12.5 cm rows with 400 seeds per square metre are suitable for rutin production because of the higher number of plants. We can recommend tartary buckwheat for achene production as a source of rutin for human nutrition or food supplement because it provides twenty-fivefold more rutin than common buckwheat.
Five varieties of common buckwheat (
Moench) were tested in field experiments for three years. The aim of the study was to investigate the influence of the variety and environmental conditions on rutin distribution in the plant. The rutin content was determined by micellar electrokinetic capillary chromatography in stems, leaves and flowers at flowering stage and in achenes at maturity. The selected varieties differed statistical significantly in the rutin content in leaves, stems and achenes. Krupinka was the variety with the highest rutin content in the aboveground part of a plant. The tetraploid variety did not contained higher rutin level than diploid varieties. Krupinka had the highest rutin content in leaves contrary to the other varieties, which had the highest rutin content in flowers. Weather conditions influenced the rutin content in flowers, stems and achenes. The plant part with the highest rutin content can be different in diverse years.
Seven varieties of common buckwheat were tested in field experiments under two levels of nitrogen fertilisation (0 and 50 kg N ha-1) during the period 1998-2000. The objective of the experiments was to evaluate the influence of varieties, fertilisation andyear on the formation of yield components in common buckwheat and to evaluate the relationships between the individual components. As was observed, a compensatory ability exists among the particular yield components. An increase in stand density reduces branching and the number of inflorescences per plant. The number of flowers in the raceme is influenced by the mean day temperature during the period from flower bud formation to the beginning of flowering (r = -0.98, P < 0.01). Rainfall during flowering negatively influenced the number of achenes per plant. The high number of flowers reduced seed setting and negatively influenced the yield due to competition for assimilates. The high number of achenes per plant was linked to lower weight (r = -0.33, P < 0.05). The occurrence of empty achenes was a result of the susceptibility of the plants to the temperature conditions during the achene maturation period (r = 0.86, P < 0.05). The main yield component determining the yield was the number of fully developed achenes per plant.