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Mikoryza wezikularno-arbuskularna roslin zielnych

63%
Probably all gymnosperms and about 85% angiosperms are able to form mycorrhizae. All terrestial gymnosperms seem to require mycorrhizae for survival and reproduction in the natural environment. Most of the herbaceous plants are exlusively VAMF partners. The VAM fungi show a wide distribution - they belong to several genera of the Zygomycetes, Glomales and Gigasporinae orders. They are obligatory biotrophic organisms, acquiring nutritional elements from living cells of plant roots. The interaction between root cells and arbuscular mycorrhizal fungi changes: quantity and quality of roots exudates; transportation of carbon between leaves, stalks and roots of plants, uptake of P, N and microelements by plants. The root colonization by symbiotic fungi contributes to biocontrol of plant pathogens, decrease of water deficiency stress and toxicity of heavy metals to plants. Plant roots colonization by VAM fungi is controlled by molecular signals. These signals reach both the fungal spores and intracellular receptors of plants on specific points on the membrane. Molecular signals from VAM fungi induce expression of specific plant symbiosis genes controlling establishment and effectiveness of mycorrhiza.
Przeprowadzono badania nad możliwością ograniczania fytoftorozy cyprysika Lawsona przy zastosowaniu bakteryjnych izolatów uzyskanych z ryzosfery i wykazujących w testach laboratoryjnych antagonizm wobec Phytophthora cinnamomi. Wykazano, że mieszanina drobnoustrojów stosowana przed sadzeniem cyprysika Lawsona do inokulowanego podłoża, istotnie ograniczała rozwój fytoftorozy w ciągu 10-tygodniowej uprawy. Zastosowanie bakterii do opryskania roślin spowodowało słabsze ograniczenie rozwoju fytoftorozy po 10 tygodniach uprawy.
Badano wpływ pięciu szczepionek mikoryzowych na wzrost i zdrowotność różaneczników i wrzosów, rosnących w podłożach zakażonych Phytophthora cinnamomi. Badania wykazały zróżnicowany wzrost i zdrowotność różaneczników i wrzosów w zależności od rodzaju szczepionki. Dwie spośród pięciu szczepionek korzystnie oddziaływały na wzrost i zdrowotność badanych roślin w podłożu zakażonym P. cinnamomi. Wybrane szczepionki, po opracowaniu technologii ich wytwarzania i warunków stosowania, mogą być wykorzystane jako środek wspomagający wzrost i zdrowotność różaneczników i wrzosów.
The effects of three selected non-fluorescent bacterial strains from the genus of Pseudomonas and spores of endomycorrhizal fungus from the genus of Glomus on the yield and mineral composition of alfalfa cv. Socza and winter wheat cv. NAD 899 as the plants tested were conducted on the erodible soils. Inoculation of seeds with Pseudomonas sp. and soil with Glomus sp. did not affect significantly the yields of alfalfa and winter wheat plants. Mineral compo­sition of alfalfa and winter wheat was characteristic of the analysed plant material (species dependent) and the concentrations of nitrogen, calcium, sodium and manganese in alfalfa plants were higher than those of winter wheat, while winter wheat contained much more phosphorus and potassium.
The aim of this research was to study whether mycorrhizal fungi colonizing the roots of ericaceous plants may be regarded as a biocontrol agent against the Phytophthora cinnamomi pathogen. The pathogen,s inoculum was mixed with the substrate 2 weeks after the planting rhododendron and blueberry plants. Five mycorrhizal inocula were prepared using the fungi isolated from roots of ericoid plants grown in natural habitat conditions. The observations on the growth and development of the rhododendron and blueberry plants were conducted 4, 8 and 12 weeks after the application of mycorrhizal inocula to the roots of tested plants. The research showed that both untreated and P. cinnamomi treated substrate, some of the tested inoculants stimulated the growth and number of leaves of tested plants, and reduced the degree of plant infection with the pathogen. The obtained results revealed the utility of used inocula to stimulate the development of ericaceous plants and reduce their infection with P. cinnamomi.
Pseudomonas fluorescens strains III107 and II21 and Bacillus mycoides strains JC192 and K184, stimulating growth of winter wheat, were chosen for the studies. The bacterial strains inhibited on agar nutrient medium the growth of Gaeumannomyces graminis var. tritici (Ggt) - the pathogenic fungus causing take-all on wheat. Both strains of pseudomonads synthesized relatively high amounts of Fe³⁺ chelators. The strains of bacilli were characterized by the very fast spreading on agar media. Furthermore, strain II21 was highly cyanogenic, and strain JC192 highly chitinolytic. Bacterization of winter wheat seeds (especially with strains III107 and JC192) significantly reduced the percentage of the plants infested with the pathogen in the 28 day glasshouse pot experiment. In the plot experiment, the winter wheat seeds were inoculated with a mixture of strains III107, II21 and JC192. Due to the bacterization the yield of wheat grain and straw was higher in comparison to the series with Ggt alone by 122% and 75%, respectively, but it amounted only to 45% and 43% of the control series not contaminated with Ggt. The decrease of percentage of wheat ears with weight less than 500 mg from 61% in Ggt-series to 25% in Ggt-bacterized-series, and especially the decrease of percentage of wheat ears with weight less than 200 mg from 43% to 14% additionally indicate the partial protection of the winter wheat against Ggt by the rhizobacteria. In the experimental series not contaminated with Ggt the percentage of these wheat ears fractions did not exceed 3% and 0.5%, respectively.
Inoculation of wheat seeds with two strains of Pseudomonas fluorescens (III107 and II21) and two strains of Bacillus mycoides (JC192 and K184) isolated from winter wheat roots, as well as with one strain of P. fluorescens (ID13) isolated from oat roots, reduced the negative influence of Fusarium culmorum on winter wheat in a 28 day pot experiment. The bacterial strains (especially III107 and chitinolytic JC192) markedly increased the plant seedlings emergence and the plant biomass (the shoots weight up to 252%, and the roots weight up to 229%) in comparison to the experimental series with F. culmorum alone. Also in a microplot experiment the yield of grain and straw of winter wheat, inoculated with the bacterial strains (especially JC192 and III107) and growing in soil contaminated with F. culmorum, was higher (the grain yield up to 120%, and the straw yield up to 139%) than in a series with F. culmorum alone (100%). In both experiments the highly cyanogenic strain II21 was least effective. A linear correlation (r = 0.926) and a rank Spearman's correlation (rSp= 0.991), both significant at p<0.01, between the weight of plant biomass in the pot experiment and the yield of whole shoots in the microplot experiment were found. It suggests that the same mechanisms worked in both experiments, although with different intensity.
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