Agnieszka Jamiołkowska

Impact of abiotic factors on development of the community of arbuscular mycorrhizal fungi in the soil: a Review

Abstract Arbuscular mycorrhizal fungi inhabiting soil play an important role for vascular plants. Interaction between arbuscular mycorrhizal fungi, plants and soil microorganisms leads to many mutual advantages. However, the effectiveness of mycorrhizal fungi depends not only on biotic, but also abiotic factors such as physico-chemical properties of the soil, availability of water and biogenic elements, agricultural practices, and climatic conditions. First of all, it is important to adapt the arbuscular mycorrhizal fungi species to changing environmental conditions. The compactness of the soil and its structure have a huge impact on its biological activity. Soil pH reaction has a substantial impact on the mobility of ions in soil dilutions and their uptake by plants and soil microflora. Water excess can be a factor negatively affecting arbuscular mycorrhizal fungi because these microorganisms are sensitive to a lower availability of oxygen. Mechanical cultivation of the soil has a marginal impact on the arbuscular mycorrhizal fungi spores. However, soil translocation can cause changes to the population of the arbuscular mycorrhizal fungi abundance in the soil profile. The geographical location and topographic differentiation of cultivated soils, as well as the variability of climatic factors affect the population of the arbuscular mycorrhizal fungi in the soils and their symbiotic activity.

MORPHOLOGICAL IDENTITY AND POPULATION STRUCTURE OF HEMIBIOTROPHIC FUNGUS Colletotrichum coccodes COLONIZING PEPPER PLANTS

Colletotrichum coccodes (Wallr.) Hughes has been recognized as one of casual agents of anthracnose roots pepper in south-eastern Poland. During 2007–2012 the species was isolated from roots of sweet pepper (Capsicum annuum L.) cultivated in the field. The purpose of the study was morphological characterization and biotic activity of C. coccodes isolates. Five randomly chosen isolates from fungus population and one reference isolate obtained from Bank of Plant Pathogens and Investigation of their Biodiversity of IPP-NRI in Poznan in Poland were studied. The character of culture like growth rate, the colour of averse and reverse and the formation of morphological structures of the fungus such as acervuli, conidia, sclerotia were studied. Ultrastructural observations of morphological structures were made using light and scanning electron microscopy. Biotic activity of C. coccodes was conducted using the method of biotic series on PDA. Seven species of test fungi were used in the study: Alternaria alternata, Aureobasidium pullulans, Gibberella avenacea, G. intricans, Fusarium oxysporum, Penicillium aurantiogriseum, Trichoderma harzianum. The biotic activity test showed that C. coccodes is a weak competitor, and its development in the rhizosphere of sweet pepper may be limited by numerous antagonists.

Biodiversity of fungi colonising aboveground parts of zucchini (Cucurbita pepo L. var. giromontina)

Abstract Zucchini is a very valuable vegetable, easy to grow both in the field and under covering, but it is affected by pathogenic fungi. The experiment was carried out at a farm near Lublin where three zucchini cultivars, ‘Astra Polka’, ‘Atena Polka F1’ and ‘Soraya’, were cultivated in a plastic tunnel and in the field in 2008-2009. The leaves, petioles and stems of zucchini were collected for laboratory tests. Mycological analysis showed that the predominating fungi were Alternaria alternata, Fusarium spp. and Rhizoctonia solani. Fusarium spp. were isolated in the greatest numbers from zucchini plants cultivated in the field. R. solani was isolated in greater numbers from zucchini cultivated in a plastic tunnel as compared to the field.