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Ustilago trichophora affects Echinochloa crus-galli and other species of Echinochloa genus. U. trichophora is a member of the order Ustilaginales, of which the germinating teliospores form a promycelium with sporidia. Investigations by Ingold (1996) proved that spores coming from various parts of the world germinate in a different way. The aim of the investigation was to determine the mode of germination of U. trichophora spores found in Poland.
A field trial with four grass species was established in the year 1996 in Prague, The stands were one or three times per year cut with the mass removing or one or two times mulched The dry mass yields and the share of the sown species (by weight method) were measured from the third to the sixth year of vegetation. The highest share of the sown species with the slowliest decreasing during the years was at Arrhenatherum elatius (41-72% in the sixth year), Bromus catharticus extincted in the fifth year. The species choose had a higher importance for conserving of the original botanical composition than the way of harvest.
Leymus chinensis (Trin.) Tzvel., a perennial grass, is a dominant species from arid to semi-arid steppes in northern China and eastern Mongolia. Phragmites communis Trin. is also a perennial grass, and is distributed widely in the world. In the natural grasslands of northeastern China, both species always co-exist as co-dominating species due to their common characteristics such as propagation both by seeds and vegetative reproduction. Replacement series experiments were used to test the effects of nutrient availability and competitive interaction on the growth performance of two clonal plant species. The experimental treatments included five nutrient levels (3.6, 7.2, 10.8, 14.4 and 18.0 kg organic matter per pot, 20 cm diameter and 15 cm deep) and five species proportions (20:0, 16:4, 10:10, 4:16 and 0:20 for L. chinensis and P. communis, respectively) with twenty tillers in total per pot. Each treatment had 10 replications. Growth characteristics including tiller height, tiller number, plant biomass, rhizome length and bud number of plants in monoculture and mixture culture were recorded and compared to examine the effects of nutrient and competitive interaction on the plant performance. The growth of L. chinensis and P. communis in mixture was influenced by the nutrient availability and competition, which depended on the combination between nutrient level and species proportion. The results implied that the intensity of competition should be lower in nutrient-poor habitats when the co-existing species demanded on the same limiting resource. P. communis benefited from coexisting with L. chinensis, especially under nutrient-rich conditions. The aboveground relative yield (RYabove) expressed in units of tiller height, dry biomass and daughter tiller number was recommended as an effective and simple index to predict the relative competitive ability for clonal plants. It was based on the regression for RY above and RYbelow (the belowground relative yield) against RY (relative yield), measured as yield in mixture divided by that in monoculture.
In multi-species grassland communities, plant growth and development are modified by both a number of habitat-related factors and physico-chemical processes resulting from the neighbourhood of other species. Plant interactions mediated through chemical substances are identified within the allelopathic processes. The allelopathic process involves excretion of bioactive compounds from plant or microorganisms that inhibit or stimulate physiological processes of the neighbour plants. The allelopathic compounds can exert a harmful impact on the emergence of seedlings, initial development and installation. Therefore, it is essential to reduce the allelopathic influence of the old sward on the plants sown as well to limit the interaction between these new plants. It is claimed that, among others, fertilizer components may partially reduce effects of allelopathic influences In this study we show the differences in growth inhibition of Ph. pratense seedlings caused by the water extracts of leaves of selected grass species and the amelioration of growth inhibition by addition of magnesium sulfate. The bioassays were performed on Petri dishes under the laboratory conditions. The activity of allelopathic substances in the leaf extracts was evaluated by the degree of inhibition of seed germination, seedling height and root length compared to the control objects (supplied with distilled water). The amelioration of the negative allelopathic effects by a complete nutrient component with or without the addition of magnesium sulfate was also evaluated against the appropriate controls and compared to the objects where blotting-paper was moistened only with leaf extracts. The present studies confirmed the defensive activity of magnesium sulfate against the allelopathic compounds of the tested grass species affecting the initial growth and development of Phleum pratense. The obtained results indicate potential elimination of the allelopathic negative influence of plants through suitable fertilization.
The aim of the study was to investigate changes in activity of catalase (CAT) and non-specific peroxidase (PX) in leaves of chosen forage grasses during pathogenesis evoked by Microdochium nivale and to state if the activity of these antioxidants could be recognized as the physiological marker of grass resistance to snow mould. Plants of Festuca pratensis cv. Skra, Festuca arundinacea cv. Kord, Festulolium braunii cv. Felopa, Lolium multiflorum cv. Tur, Lolium perenne cvs Darius and Taya were hardened and then inoculated by snow mould caused by Microdochium nivale. The leaf samples were collected prior to infection, and 2, 4 and 8 days after inoculation. Each plant cultivars demonstrated specific activity of catalase and non-specific peroxidase. Skra and Taya recognized as more tolerant to M. nivale showed inhibited CAT activity during pathogenesis, however the infected plants of cv. Skra were characterized by a lower CAT activity than the control during the whole time of experiment, while cv. T aya 4 and 8 days after inoculation. No universal pattern of PX activity for all studied plant species was found. Skra cv. demonstrated the highest PX activity especially 8 days after the infection. Grass resistance to M. nivale may be evaluated on the basis of activity of both catalase and non-specific peroxidase. Plants more resistant to this disease are characte-rized by inhibited activity of catalase and activation of cell wall peroxidases.
Initiation of tissue culture of many plant species is a very difficult stage due to appearance of many contaminations. The other problem might be a choice of media for regeneration. Initiation of grass species tissue cultures are thought to be very difficult. Therefore, a research was undertaken to evaluate the use of nano-silver particles for plant material disinfection and to estimate a medium Pennisetum alopecuroides. The plant material were buds and nodal explants that were disinfected in 2% NaOCl for 30 min or 0.1% HgCl2 for 1 min. Half of the explants disinfected with NaOCl were soaked in 50, 100 or 250 mg·dm–3 Ag NPs for 1 hour. Explants not soaked in nano-silver were placed on media with Ag NPs at concentrations of 4, 8 or 16 mg·dm–3. An influence of growth regulators on Pennisetum alopecuroides was evaluated in vitro. Regenerated shoots were placed on MS media with: 3 mg·dm–3 BA + 0.3 mg·dm–3 IBA, 3 mg·dm–3 KIN + + 0.3 mg·dm–3 IAA, 1 mg·dm–3 BA + 0.1 mg·dm–3 IBA. It was observed that the use of nano-silver particles lowered the level of contamination. The best results were obtained when Ag NPs was used at concentration of 100–250 mg·dm–3 alone or as a supplementation of the media, at concentration of 4 mg·dm–3 for nodes and 16 mg·dm–3 for adventitious buds. The use of nodal explants allowed to obtain less contamination. Regeneration depended on a media content. The most regenerated shoots were obtained on the MS media supplemented with 1 mg·dm–3 BA and 0.1 mg·dm–3 IBA.
The primary goals of this study were to quantify the composition and size of bud banks and to evaluate the roles of bud banks of main dominant species Leymus chinensis (Trin.) Tzvel. and Carex duriuscula C.A. Mey. in population maintenance over a 2-year period. The four experimental plots were in early, early-mid, middle and late seral stages of a flooded restoration succession after they had approximately 12, 10, 8, and 6 months’ flood durations in the Songnen meadow, China. Five quadrats (each 0.25 ´ 0.25 m in area and 30 cm deep) were each sampled in four seral spots. The differences of L. chinensis and similarity of C. duriuscula in bud bank characteristics persisted in the studied seral stages from year to year. In each seral stage, rhizome buds comprised most of the L. chinensis bud banks in 2003; in 2004, juvenile tillers predominated. Rhizome buds consisted of the majority of C. duriuscula bud banks throughout the study period. The bud densities of L. chinensis and C. duriuscula experienced a significant linear increase with the increase of tiller density at different seral stages each year, but the slopes of these relationships in L. chinensis were higher than those in C. duriuscula. The total bud densities of C. duriuscula showed a significant linear decrease corresponding to the increase of those of L. chinensis from the early to the late seral stage in 2003 and 2004. Bud banks are vital for population maintenance and the number of bud banks is a good predictor of population dynamics.
The usefulness of grass mixtures for biological reclamation of municipal dumping ground was investigated. Five mixtures and inter-genus hybrid Festulolium were sown on plots treated with 20, 40 and 60 t of sewage sludge per hectare. The highest biomass production was achieved on plots with Festulolium, and the best sodding was formed by Lolium perenne and Festuca rubra species. Dose of 40 t·ha-1 was the most favorable referring to sodding effect and biomass production under experimental conditions. Investigations point out to the usefulness of further study upon Festulolium.
The field experiments were carried out in 1994–1996 and were aimed at determining the nutritional value of mixtures containing Trifolium pratense L. + Lolium perenne L., Lolium multiflorum Lam., Lolium multiflorum Lam. var. westerwoldicum and Lolium x boucheanum Kunth. and Trifolium pratense L. + Festuca pratensis Huds.. Based on the botanical analysis, chemical composition and nutritional value, an attempt has been made to determine the variability of the parameters depending on the grass species. The percentages of grasses varied significantly and the variability expressed in the coefficient of variance ranged from 44 to 72.
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