Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 9

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  grzyby zasiedlajace nasiona
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The object of the experiment were seeds of two traditional cultivars of yellow lupin (Juno and Amulet) cultivated in 1999 in two crop-rotation with 20% and 33% yellow lupine contribution. The quantitative and qualitative composition of the fungal community colonizing the seeds were determined in the laboratory conditions after 0.5-, 1.5- and 2.5-year of storage time. In total 1077 fungal colonies were isolated from the lupin seeds. Fungi representing the species of Penicillium - 29.3%, Alternaria alternata - 26.7% and Rhizopus nigricans - 12.7% were isolated most widely. Among the fungi pathogenic to lupin, the species of Colletotrichum gloeosporioides (16.3% isolates) was dominant. The crop rotation with 20% lupin reduced the number of fungal colonies colonizing the seeds including the pathogens from the species of C. gloeosporioides. Seed disinfection decreased the total number of fungal colonies isolated from both cultivars. Higher number of C. gloeosporioides isolates was found in the combination with disinfected seeds. More fungal colonies were obtained from seeds of cv. Amulet than from those of cv. Juno. The storage duration had an effect on the population and the composition of species of fungi isolated from seeds of yellow lupine. With longer storage population of Penicillium spp. and Rhizopus spp. increased, whereas the population of C. gloeosporioides decreased.
The aim of studies was to determine typical composition of fungi occurring on seeds of Stewartia pseudocamellia.The studies conducted on 100 disinfected and 100 nondisinfected seeds of these plants. Isolates of Alternaria alternata, Fusarium oxysporum, Cylindrocarpon radicicola and Rhizoctonia solani were characterized by pathogenicity towards the investigated Stewartia pseudocamellia. In the laboratory experiment, 204 isolations of microorganisms were obtained that belonged to 20 species and form of fungi and bacteria. Among fungi there were both of parasite (Alternaria alternata, Botrytis cinerea, Fusarium spp., Rhizoctonia solani) and typical saprophytic (Cladosporium spp., Penicillium spp., Aspergillus spp., Epicoccum spp., Mucor spp.). The dominant fungus on seeds was Alternaria alternata. Among the investigated isolates only one isolate (R₄) Rhizoctonia solani, was strongly pathogenic, isolates (A₁) Alternaria alternata were weakly pathogenic to seedlings of Stewartia pseudocamellia.
The seeds of forest trees usually transfer numerous fungi species, including pathogens, facultative parasites and saprotrophs. The aim of the present work was to determine qualitative and quantitative composition of fungi inhabiting the seeds of 10 trees species i.e.: birch (Betula pendula Roth.), beech (Fagus sylvatica L.), red oak (Quercus rubra L.), common oak (Quercus robur L.), sycamore maple (Acer pseudoplatanus L.), black alder (Alnus glutinosa Gaerth.), fir (Abies alba Mill.), European larch (Larix decidua Mill.), pine (Pinus sylvestris L.) and spruce (Picea abies (L.) H. Karst). The seed samples were obtained courtesy of 5 forest districts located in the south−eastern Poland. Mycological analysis was performed in the years 2012−2013. Each time, the study included 100 surface− −disinfected seeds of particular plant species. As a result of the study about 2000 colonies of fungi representing 26 genera and above 39 species were isolated. The most frequently occurring species were: Fusarium spp., Penicillium spp., Alternaria alternata, Cladosporium cladosporioides, Trichoderma koningii, Epicoccum nigrum, Phoma spp. and Cylindrocarpon destructans. Moreover Discula spp., Phyllosticta spp., Pyrenochaeta spp., Rhizoctonia solani, Alternaria consortiale were obtained only from the seeds of deciduous trees while Truncatella angustata and Sphareopsis sapinea exclusively from the seeds of coniferous trees. The genus Fusarium was represented by 8 species and among them F. avenaceum, F. oxysporum and F. sporotrichioides dominated. Moreover Penicillium spp., Epicoccum nigrum, Trichoderma koningii, Botrytis cinerea, Cladosporium cladosporioides, Chaetomium globosum and Trichothecium roseum were commonly isolated while the other species of fungi were present in smaller numbers. Isolation of numerous fungi species which may cause mold of sowing material, seedling blight as well as leaves and needles spot, indicates their big threat for seeds during storage and for plants in the initial period of growth in a nursery. The obtained results show that the seeds, besides the infected soil, are a very important source of infection for young plants.
Seeds of Abutilon theophrasti grown in Poland were colonized at least by 11 species of fungi. Alternaria alternata was the most common species. Its frequency in the fungal community amounted to 62%. Epicoccum nigrum and Aspergillus spp. were also common fungi on/in seeds, occurring usually with local or temporal peaks. Other fungi, including Fusarium, Botrytis cinerea, Sclerotinia sclerotiorium and Trichothecium roseum occurred sporadically.
The research was conduced in the years 1999-2000. The aim of the research was to determine the health condition of overground parts and seeds of the following spring oilseed crops: crambe (Crambe abbysinica Hoechsl.) cv. B o r o w s k i, false flax (Camelina sativa L.) cv. B o r o w s k a, spring rape (Brassica napus ssp. oleifera L.) cv. M a r g o and oleiferous radish (Raphanus •tivus var. oleiferus L.) cv. P e g 1 e t t a. In all the years of the research alternaria, light was found on the leaves and siliques of spring rape and oleiferous radish and on the leaves and stems of crambe. False flax proved to be weakly infected by •pathogens. On its leaves gray mould (Botrytis cinerea) was found in all the years, of the research. The disease was found on the siliques only in 1999. In 2000, powdery mildew was found on spring rape and false flax (respectively, Erysiphe cifearum and E. cichoracearum). The weather conditions affected the intensity the diseases on the studied spring oilseed crops. Alernaria genus, especially A. alternata was most commonly isolated from the of examined p!ants. It constituted from 37% (in crambe) to 63.3% (in spring) of all the isolates. Of the remaining pathogenic species, numerous fungi of Fusarium genus (F. avenaceum, F. culmorum, F. equiseti and F. oxysporum) isolated. They constituted from 1.0% (false flax) to 17.3% (crambe) of the isolates.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 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.