Ograniczanie wyników

Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 26

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  rye-grass
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
In pot experiments carried out in 2005 and 2006, tolerance to sodium chloride salinity of 4 cultivars of perennial ryegrass (Lolium perenne) (‘Nira’, ‘Stadion’, ‘Ronija’, ‘Darius’) was studied. Three concentrations of NaCl in medium (earth + sand): 0.0 mM (control); 50 mM; 100 mM, were used in the investigations. In three successive crops of grass, fresh weight yield of leaves, stomatal conductance, photosynthesis intensity, content of chlorophyll and PS II maximum quantum yield (Fv/Fm) were determined. The obtained results showed that perennial ryegrass is a species tolerant to NaCl salinity. Among the studied cultivars, cv. ‘Ronija’ showed the highest tolerance, whereas cv. ‘Nira’ showed the lowest. The growth of perennial ryegrass plants under salinity conditions was limited by low stomatal conductance of leaves and photosynthesis, but not by the photosynthetic activity of chlorophyll and its contents.
The aim of the present research was to evaluate the yielding of perennial ryegrass (Lolium perenne L.), 'Stadion' lawn cultivar grown for seed, depending on the sowing method, date and row spacing. The research was carried out at the Experiment Station for Cultivar Testing at Chrzšstowo, in the vicinity of Bydgoszcz. The experiment was carried out over 1998-2002 in three series; each of them included the sowing year and two years of full use for farming purposes. The experimental factors included: I - sowing method/date: autumn pure stand, spring pure stand, undersown perennial ryegrass in spring barley cultivated for green matter and undersown perennial ryegrass in spring barley grown for grain, II - row spacing: 12 cm - narrow, 24 cm - average wide, 36 cm - wide and 48 cm - very wide. In the first year of full use for farming purposes, the seed yields were lowest when ryegrass was sown in autumn. Furthermore the yield of perennial ryegrass sown in spring in pure stand was significantly lower than that of undersown perennial ryegrass in barley in both its growing variants. The seed yield in the second year was significantly higher for sowing together with a cover crop, as compared with the yields obtained for autumn sowing. The application of varied row spacing showed a significant effect on the seed yield neither in the first nor in the second year of full use for farming purposes.
The waste activated sludges had a significant influence on the content of macroelements in Lolium multiflorum whereas waste activated sludges from the Drosed Co. were a better source of nutrients for plants than the waste activated sludge from Siedlce. All other parameters investigated, such as type of soil and liming also had a significant influence on the features investigated.
A pot experiment was carried out under controlled conditions to evaluate the combined effect of chemical oxygen demand and heavy metals in synthetic irrigation water on the accumulation of heavy metals in perennial rye grass (Lolium perenne) grown during 30 days on two soils: an acidic sandy soil (pH = 4.0), and the same soil amended with 5% clay (pH = 6.7). The dry matter yield of rye grass decreased and heavy metal concentrations in plant tissue increased with heavy metal concentration in the irrigation water. A higher COD concentration in the irrigation water also resulted in an overall decrease of dry matter yield and higher metal contents. The addition of 5% clay to the acidic soil reduced these effects. However, the clay content of the soil was by far the most important factor in controlling plant growth and metal uptake.
The increasing demands being placed on natural grasslands in the era following the appearance of Bovine Spongiform Encephalitis require that forage crops provide a reliable extended season of growth, combined with good winter survival to ensure sward longevity. The ability to tolerate sub-zero temperatures is integral to the survival of perennial forages. Since the development of freezing tolerance is crucial to the survival and productivity of over-wintering crops, forage breeding programmes require an improved understanding of the individual characteristics that contribute to tolerance to sub-zero temperatures. Photosynthesis, carbohydrate content and changes in protein composition were investigated in two varieties of Lolium perenne which differ in their response to growth at low temperature.
Winter hardiness of plants is limited mainly due to sensibility to Iow temperature and winter fungus damages. Snow mould is a disease that affects many species of winter cereals, turf and forage grasses. In Poland it is caused mainly by the common and economically important fungal pathogen Microdochium nivale causing pink snow mould, destructive disease of seedlings, stem bases and ears. The aim of the study was to investigate the dynamie of Microdochium nivale infection and cytological changes in cold-hardened Lolium perenne Danish cv. Darius. Plants were inoculated with mycelium. The studied plants demonstrated fast defence response to fungus attack, accumulating phenolics already one day after inoculation, however no infecting hyphae within leaf tissue at this time were detected. The first infection hyphae in plants were observed two days after inoculation. Microscopy observations revealed sheaths of the youngest leaves located in the crowns as the main infection way. These observations showed that Microdochium nivale hyphae uptake nutrients from the host by haustoria damaging the protoplasts of mesophyll cells causing their strong plasmolysis. This type of feeding is characteristic for biotrophic and hemibiotrophic parasites. Our observation proved that Microdochium nivale is a hemibiotrophic pathogen and inoculation with its mycelium is very effective and fast and causes serious damages of Lolium perenne cells.
Alfalfa, tall fescue, ryegrass, and celery, some of which were inoculated with the AM fungus Glomus intraradices, were compared for their contributions to phenanthrene (PHE), pyrene (PYR), and dibenzo( a,h)anthracene (DBA) dissipation in spiked soil. A pot experiment was conducted in which PAHs extracted from soil and plant, quantity of PAH degraders, and plant biomass were evaluated. The results showed that biodegradation was the dominant removal mechanism for PAHs from soil while PAH accumulation in the plant tissue was negligible. PAH dissipation varied with the plant species and decreased with the increase of PAH molecular weight. The four plant species displayed a positive effect on PHE dissipation, and alfalfa improved PYR and DBA dissipation. AM fungi significantly increased plant biomass, phosphorus uptake, and PHE removal rate in planted treatments. Plant biomass and PAH degraders showed a weak linear relationship with PAH dissipation, indicating that there might be other important factors influencing PAH dissipation.
The yield of Lolium multiflorum harvested after fertilization with waste activated sludges from both sewage purification plants were higher than from the control and FYM objects. Total sulphur content in plants was very differentiated (i.e. it ranged from 1.0 to 8.4 g kg-1 of DM) and depended on all experimental parameters investigated.
The effect of soil drought on leaf water content, proline content, and the activity of guaiacol (GuPX) and ascorbate (APX) peroxidases as well as the level of lipid peroxidation were investigated in leaves of drought resistant red fescue (Festuca rubra) and drought sensitive perennial ryegrass (Lolium perenne). Plants were grown under glasshouse conditions in soil pot culture. 26 day-old grasses were exposed to drought by withholding irrigation for 18 days. Water content in leaves of perennial ryegrass decreased more than in red fescue throughout the experimental period. On the other hand, proline content (PC) was higher in red fescue. The activity of APX and GuPX increased in leaves of red fescue, while it did not change in perennial ryegrass. Our data demonstrate that both red fescue and perennial ryegrass were able to survive applied drought, as shown by a lack of stress-induced lipid peroxidation and hence no evidence of oxidative damage. We speculate, that the observed drought stress tolerance at cellular level was associated with the ability to accumulate proline, and to maintain high activity of APX and GuPX, resulting in protection against oxidative damage and lipid peroxidation. It seems that this mechanism works better in red fescue.
Phosphorus is essential for the growth and development of plants. It also determines the quantity and quality of plant yields. Phosphorus actively participates in many vital processes and forms part of numerous substances indispensable for a normal course of certain biochemical changes. Unfortunately, phosphorus deficiency is quite common in grasslands. As a result, the content of phosphorus in soil is insufficient to meet nutritional requirements of forage crops and, consequently, the concentration of this element in green forage is insufficient to meet nutritional requirements of ruminants. The aim of the present study was to determine the effect of phosphorus deficiency in soil on the rate of photosynthesis and transpiration, water use efficiency, leaf greenness and the yield of some cultivars of perennial ryegrass (Lolium perenne L.) and orchard grass (Dactylis glomerata L.). A greenhouse experiment was conducted to assess the rate of photosynthesis and transpiration, water use efficiency (WUE), leaf greenness (SPAD - Soil-Plant Analysis Development) and the yield of perennial ryegrass (Lolium perenne L.) and orchard grass (Dactylis glomerata L.) grown under conditions of phosphorus deficiency in soil. The rate of photosynthesis and transpiration was measured using a LiCor 6400 gas analyzer (Portable Photosynthesis System), and leaf greenness was estimated with a Minolta SPAD-502 chlorophyll meter. Dry matter yield was determined by drying green matter to constant weight at 105 st.C. The results of the study indicate that phosphorus deficiency significantly decreased the rate of photosynthesis, water use efficiency and the yield of perennial ryegrass and orchard grass. At the same time, it increased the rate of transpiration and leaf greenness values. Among the tested cultivars, orchard grass cv. Areda was found to be the most resistant to phosphorus deficiency in soil, which was confirmed by the slightest reduction in the examined parameters.
In greenhouse experiments the susceptibility of meadow fescue, perennial ryegrass and ltalian ryegrass to Fusarium avenaceum, F. culmorum and F. graminum infection was studied. Various responses to Fusarium spp. infection were observed among the tested grass species and their cultivars. Meadow fescue was the most susceptible to all the Fusarium isolates used. F. avenaceum isolates also strongly reduced perennial ryegrass emergence. In the experiments with Italian ryegrass the number of seedlings having survived the artificial infection of seeds with Fusarium spp. was significantly larger for Atos, Gran, Milos and Polus cultivars than for Kroto, Lotos and Tur. All of the studied grasses were more susceptible to the strongly pathogenic F. avenaceum isolates than to F. culmorum and F. graminum isolates, having moderate pathogenicity.
A total of 231 different soil Streptomyces isolates were recovered from 16 different locations in North Jordan. They were assessed for their phytotoxic activity on seeds of cucumber (Cucumis sativus L.) and ryegrass (Lolium perenne L.) placed adjacent to a 2 cm wide Streptomyces culture strips grown at 28C° for 3 weeks on starch casein nitrate (SCN) agar. Phytotoxicity was ascertained on the basis of suppressed seed germination, discoloration of the root tip, reduced root and the shoot growth and eventual death of the root. Twenty one of the isolates exhibited adverse effect against growth of germinated cucumber seeds, germination and growth of ryegrass seeds. Using filter paper bioassay method, culture filtrate from the SCN broth of the isolate R9; identified as Streptomyces aburaviensis, significantly inhibited seed germination, radicle and shoot growth of ryegrass, reduced radicle and shoot growth of cucumber and suppressed the shoot growth of milk thistle (Silybum marianum L.). Also, culture filtrate from the glucose-peptone-molasses (GPM) broth diluted (1:1) with sterilized distilled water caused complete inhibition of seed germination of redroot pigweed (Amaranthus retroflexus L.). Dichloromethane extracted fraction of S. aburaviensis (strain R9) culture filtrate from GPM broth completely inhibited seed germination of ryegrass when applied at doses of 3 and 5 mg of dry weight, and the seedling growth of cucumber and milk thistle was severely reduced by the same doses.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.