The growth and development of fungus phomopsis helianthi m. on different nutrient medium

It is known that selection of fungi in pure culture and observation in vitro is first step for further research of their nature of growth and development, morphogenesis, establishment of ecological features, impact of such factors as temperature, humidity, sources of light, acidity, radiation, and component composition of substrate. The presence of pure cultures makes it possible to identify biosynthetic activity of metabolic products, identifying their degree of parasitism and resistance to fungicides, implementation of population and comparative studies of different isolates. In this regard, intensity research of growth and development of mycelium and variability processes and morphological and culture characteristics of Phomopsis helianthi in different culture agar is relevant. The aim of study was to examine influence of culture agar on the growth and development of fungus . Isolation of the fungus Phomopsis helianthi in pure culture and its identification was performed according to standard techniques. In particular, selected stalks of sunflowers with phomopsis symptoms, cut them into 5-10 mm fragments, were sterilized in 96° alcohol and placed in Petri dishes on the surface of potato-glucose environment. In the future prepared material were incubated in the thermostat for two weeks. Nutrient environments was prepared according to standard formulations. In further studies we used the following nutrient environments: potato-glucose agar (CCA), sunflower seed agar (MA), oatmeal agar (VA), Wednesday Capek (H), carrot agar (MA), bean agar (CA), hungry agar (HA). For inoculation of substrates used culture 2 weeks of age. The mycelia were sown in Petri dishes in the center of surface in dense nutrient environment by small piece of inoculum, measuring about 5×5 mm, always same density and age. Investigation of  morphological characters variability of fungus depending on influence of component composition in nutrient environment was studied at the optimum, 23-25 °C temperature. The diameter of colonies was measured daily in two mutually opposite directions. Described cultural morphologic features of colonies on different culture environments. Repeated experiments fourfold. Installed that on all nutrient environments, potato-glucose agar, sunflower seed agar, oatmeal agar, the substrate capek, carrot agar, agar casaleone and starvation agar marked fungus Phomopsis helianthi vegetative growth. The beginning of micromycete growth was observed on the second day of cultivation. The most intensive increase in the area of the colony is marked Phomopsis helianthi on potato-glucose, oat and sunflower agars. In particular, on 11th day of incubation, the diameter of pathogen colonies were respectively 80,5, 79,0, 70,75 mm. More slowly fungus grew on the environment capek and hungry agar, which in specified period of time diameter of colonies was made up to 53.5 mm and 43.5. Bean and carrot agar provided the least intensive growth of Phomopsis helianthi : the diameter of micromycete colonies grew, respectively, to 32.8 and 31.8 mm. During the cultivation of Phomopsis helianthi in different culture agar  recorded changes of  morphological and cultural characteristics fungus mycelium, including its color and density education picnid. Potato-glucose agar provided the formation of a dense, air-olive color of the mycelium, on carrot agar was formed well developed, white, dense mycelium. On all studied substrates, the mycelium formed was white in color, which differed in density. The most intensively pycnidia were established on carrot agar, where their number was 12.3±0,54 PCs /cm 2 Perspectives of mycelium pathogen growth occurred in different environments: potato-glucose agar, sunflower seed agar, oatmeal agar, the agar capek, carrot agar, agar casaleone and starvation agar. Intensive dynamics of colonies size increasing  of fungus Phomopsis helianthі observed on potato-glucose, oat and sunflower agars that on the 11th day of incubation was equal to, respectively, 80,5, 79,0, 70,75 mm. Type of nutrient agar used, greatly influenced on the colony color, culture and structure of fungus. The nutrient substrate influenced the formation of morphological structures and cultural characteristics of fungus Phomopsis helianthi, in particular, the formation of picnides. The most intensively fungus pycnidia were formed on carrot agar in  average of 12.3 units/cm 2 of substrate surface. On hungry agar formation pcnd occurred. Thus, we established that growth and development of  pure culture of fungus Phomopsis helianthi depends on the component composition of the nutrient substrate. Accumulation in vitro in a short period of time, the mycelium of Phomopsis helianthi for biochemical, population and comparative studies possible on a potato-glucose, oat and sunflower agars. To study morphological and cultural characteristics mycelium of the fungus, including processes sporules, you need to use a carrot agar, where is highest intensity education picnid. Key words: Phomopsis blight, the mycelium diameter of the colonies, growth rate, pycnidia