Potato Glucose Agar Research Articles

Linear Growth of Representatives of Wheat Seeds Mycobiota

Seed-born fungi of wheat interact with the plant at various stages of its development and with each other. With the highest growth rate, they should be isolated because of competition. The purpose of this study was to compare the growth of colonies on a nutrient medium for the gradation of fungal genera and species from wheat seeds according to aggressiveness. These data helped concluding on the effectiveness of mycoexpertise of winter wheat seeds. Potatoglucose agar (PGA) was used for the analysis of the fungal complex. Seven-day fungal cultures were sown in the centre of Petri dishes. Linear growth of fungal colonies on PGA with gentamicin was determined. The specific features of the development of 12 representatives of seeds mycobiota from the Northeast of Ukraine of the 2017-2019 harvest were investigated. The dominance of Alternaria sp. and a slight release of Fusarium sp. were established by analysis of the fungal complex. The first comparison of the linear growth of Fusarium graminearum, F. poae, and Alternaria tenuissima in 2017 showed that Fusarium colonies grow faster on nutrient medium. In 2018, the growth characteristics of A. arborescens, which quickly became dominant in wheat seeds mycoflora, and the littlecommon Trichothecium roseum were studied in detail. By comparing the growth of fast-growing F. graminearum with the common Aureobasidium pullulans and the aggressive Nigrospora oryzae, the fastest development of the third and the slowest of the second species was established. F. poae filled the Petri dish on day 6, Penicillium – on day 22. In 2019, in the first experiment comparing F. poae, F. sporotrichioides, and A. avenicola, the second species had the worst growth rates. It became the second fastest growing colony in the study of the growth of seven species in the second experiment. Isolates of N. oryzae in 2018 were more aggressive than in 2019. Specific features of colony growth on PGA did not affect the effectiveness of the analysis of mycobiota of winter wheat seeds. N. oryzae had the highest radial speed under the general dominance of Alternaria sp. Fusarium sp. (F. poae, F. sporotrichioides, F. verticillioides, and F. graminearum) and B. sorokiniana developed rapidly. A. arborescens and A. avenicola grew at the same level as A. pullulans. Penicillium and T. roseum lagged behind other fungi in speed and filled Petri dishes for the longest time. A. tenuissima had the lowest radial growth rate

Brown Culm Rot of Dendrocalamus latiflorus Munro Caused by Diaporthe guangxiensis in Sichuan Province, China.

Dendrocalamus latiflorus Munro, the most widely cultivated bamboo species in southern China, has high ornamental value used in gardens, while culms are also used for buildings and as fibers and edibles (Gao et al. 2011). In June 2020, brown culm rot of bamboo was observed in Yibin city, Sichuan Province, in an area of approximately 1000 hectares. Disease incidence was approximately 60%, of which 30% of the plants had died. At the end of June, the lesions expanded but did not surround the base of the culm. From the end of June to the beginning of September, the lesions expanded upward and formed a streak, of which the color gradually deepened to purple-brown and black-brown. At the same time, the disease spots at the base of the culm also expanded horizontally. After the spots surrounded the base of the culm, the diseased bamboo died. Ten culms showing typical symptoms were collected and cut into 5×5 mm pieces at the junction of infected and healthy tissues. The tissues were sterilized for 1 to 2 min in 3% sodium hypochlorite, decontaminated in 75% alcohol for 3 to 5 min, placed on modified potato glucose agar (PDA) with streptomycin sulfate (50 μg/ml), and incubated at 26°C. Two isolates were obtained by the single-spore method (Sivan et al. 1992). The isolates both produced white round colonies similar to Diaporthe guangxiensis and two types of conidia: one was α type (5.5 to 8.2×1.0 to 2.8 µm, n=30), colourless, single-celled, undivided, and oval, containing two oil droplets; and β type (21.1 to 30.2×0.8 to 1.4 µm, n=30), colourless, single celled and hook shaped. Genomic DNA was extracted from the two isolates by using a fungal genomic DNA extraction kit (Solarbio, Beijing). The products were amplified by polymerase chain reaction (PCR) with primers for the internal transcribed spacer 1 (ITS) region (White et al. 1990), calmodulin (CAL) gene (Carbone and Kohn 1999), translation elongation factor 1-alpha (TEF) gene (Glass and Donaldson 1995) and beta-tubulin (TUB) gene (Soares et al. 2018). The amplified products were sequenced and blasted in GenBank (accession numbers MW380383, MW431318, MW431317 and MW431316 for ITS, CAL, TEF, and TUB, respectively). The ITS, CAL, TEF, and TUB sequences showed 100%, 99.33%, 100%, and 99.80% identity to D. guangxiensis JZB320094 (accession numbers MK335772.1, MK736727.1, MK523566.1, MK500168.1 in GenBank), respectively. To evaluate the pathogenicity of the isolates, five plants were each inoculated with two isolates. The cortex of potted bamboo were injured locally with sterilized needle, and the bamboo culms were inoculated with 100 μl of conidial suspension (105 cfu/ml). The surface of the inoculation wound was covered with gauze soaked with sterilized water. Five plants inoculated with sterile water were used as controls. The treated plants were maintained in a greenhouse at a temperature of 22 to 29°C and relative humidity of 70 to 80%. One month later, of all inoculated plants showed similar symptoms as those observed in the field. D. guangxiensis was re-isolated from all inoculated plants. The pathogenicity test was repeated three times with similar results. This is the first report of D. guangxiensis causing brown culm rot of D. latiflorus in China. These results will facilitate an enhanced understanding of factors affecting bamboo and the design of effective management strategies of the pathogenic species on bamboo and thus to develop corresponding control measures.

Low molecular weight chitosan hydrolyzate inhibits the growth of some phytopathogenic Ascomycota fungi

The work studied the effect of low molecular weight chitosan hydrolyzate on the growth and development of phytopathogens Botrytis cinerea, Fusarium solani, Alternaria solani. Chitosan hydrolyzate, when added to potato-glucose agar, inhibits the growth of mycelium in vitro of Botrytis cinerea, Fusarium solani, Alternaria solani. Treatment with chitosan hydrolyzate suppresses the development of fusarium on tomato leaves and the development of gray rot on fruits. Further studies of chitosan hydrolyzate effect mechanisms on plants can expand the scope of its application.

Lytic Exoenzymes of Soil Strains of Bacillus Representatives and Manifestations of their Biological Activity

Bacteria of the genus Bacillus make up a significant (8–12%) part of the soil microbiome. Manifestation of their biological activity, in particular, the antagonistic and lytic activity against other microorganisms directly depends on their exometabolites. According to the literature, such properties of soil bacteria of the genus Bacillus thus can be related to their various lytic exoenzymes. Aim. To evaluate the role of lytic exoenzymes of the studied soil bacteria strains of the genus Bacillus in the manifestation of their biological (antagonistic, lysing) activity. Methods. The antagonistic activity of bacteria strains of the genus Bacillus against phytopathogenic micromycetes was determined by the method of double culture in Petri dishes on potato-glucose agar. For qualitative analysis of the presence of extracellular enzymes, strains of bacteria of the genus Bacillus were plated on Petri dishes with solid mineral-salt medium and a suitable substrate inducer. The ratio of the diameter of substrate hydrolysis zone to the diameter of the colony was taken as the relative enzymatic activity of the culture. Bacteriolytic activity of the studied strains was determined by the change in optical density of living cells of phytopathogenic bacteria suspension at 540 nm. Results. Six strains of bacteria of the genus Bacillus were selected by the results of preliminary screening, with at least five types of lytic activity, namely proteolytic, chitinase, amylolytic, cellulase, and xylanase of different levels (low, average, high). Analysis of the antagonistic activity of the selected strains of bacteria of the genus Bacillus to the main groups of phytopathogenic bacteria (six test cultures) singled out the strain Bacillus sp. 41 for a careful study of the nature and spectrum of its antagonism. Analysis of the level of antagonistic activity of the selected Bacillus strains against the phytopathogenic micromycetes showed that the minimum decrease of antagonism (the decrease of growth inhibition zones) during the observation period (at the 3rd and 7th days) was in Bacillus sp. 41 strain. Therefore, only this strain showed a stable and relatively wide range of antagonistic activity against phytopathogens of bacterial and fungal etiology. The nature of this antagonism is probably complex and conditioned by the participation of various biochemical mechanisms, in particular, the synthesis of a complex of lytic exoenzymes. To assess the lysing activity of Bacillus strains, three strains with the highest proteolytic and cellulolytic activity of exoenzymes were taken from the six previously chosen. Only Bacillus sp.1913 strain showed high (70%) lytic activity against gram-negative polyphagous phytopathogen Pseudomonas syringae pv. syringae UCM B-1027T. Such activity of the strain did not manifest against the rest of the phytopathogenic test cultures. The high lytic activity of Bacillus sp. 1913 strain may be associated with high activity of exogenous proteases and cellulases of the lytic complex, which is quite consistent with the literature data on the lytic activity of bacteria of the genus Bacillus. Conclusions. The spectrum and activity of lytic exoenzymes of strains of the studied soil bacteria of the genus Bacillus indicate the indirect participation of these enzymes in the manifestation of biological activity (antagonistic and lytic).

Growth, cultural and morphological characteristics of strains of Laetiporus sulphureus (Polyporales, Basidiomycota) under the influence of laser irradiation

The article provides growth, cultural and morphological characteristics of the vegetative mycelium on agar nutrient medium under the influence of laser irradiation for three strains of Laetiporus sulphureus from the Collection of basidiomycete cultures of the Department of Botany and Ecology of Vasyl' Stus Donetsk National University. The study was performed on potatoglucose agar (PGA) at a temperature of 26 ± 1 °C. It has been found that cultural and morphological characteristics of the colonies and the radial rate of their growth depend on the duration of irradiation (5 and 10 s) and the wavelength of light – green (532 nm), blue (405 nm) and red light (635 nm). For all studied strains of L. sulphureus, the most effective irradiation is that with green light (irradiation energy 51.1 mJ/cm2) lasting 10 s. Under the influence of this regime, the rate of radial mycelium growth increased from 23.4% to 66.7%, respectively, and the inoculum and the central zone of the surrounding colony formed a denser and higher mycelium of a pale sandy color. In general, the cultural and morphological features of the mycelial colonies of L. sulphureus strains under different conditions were somewhat different, but they were typical for this species.

Характеристика складу мікроміцетів осушуваних грунтів басейну р. Трубіж

The study of the quantitative and qualitative composition of the soil microbiota, which adequately reflects the degree of anthropogenic load, can be applied as an indicator of assessment of the ecological status of the soil of anthropogenically transformed biogeocoenosis.The aim of the article is to analyze the species composition of micromycetes of drained soils of the Trubizh river Basin as an indicator of the ecological condition of the soil of different degrees of economic activity. For microbiological analysis samples of organogenic (lowland deep and medium peat soils) and mineral (meadow-chernozemic) soils were used. The samples selected from four experimental plots with different degrees of anthropogenic load. In particular, the first plot is a long-term use fallow (more than 15 years) on deep peatlands, the second one is a field with corn for grain on medium peatlands. The third plot is a field with post-harvest soybean residues on medium peatlands and fourth one is fallow with annual and perennial grasses on meadow-chernozemic soils. Soil samples were taken from the root layer at a depth of 0-5, 5-10 and 10-20 cm according to the current DSTU. Isolation of micromycetes was carried out by dilution method of soil with the object of estimation of the concentration (number of colonies, micromycetes). The count of micromycetes was estimated on surface of potato-glucose agar and Chapek's agar plates and was determined by the number of colony forming units (CFU). It was established that in the plot with increased anthropogenic impact (field with corn for grain on medium peatlands) the total number of isolated micromycetes was twice less than in plots of fallow lands and soybean. There was observed very poor species compositions (13 species). 2 species (15%) of Zygomycota, where predominant concentration was Mucor plumbeus in the soil layer 0-20 cm and 11 species (85%) of Ascomycota were found. In all plots, the basis of micromycete complexes was formed by fungi-destructors of plant remains and root secretions of the genus Penicillium. The micromycetes of drained soils of the Trubizh river Basin was presented the biggest phylum Ascomycota (83-95.5%) and the phylum Zygomycota (4.5-17%) also.

Isolate Neoscytalidium dimidiatum fungal pathogens from pytaya (Hylocereus undatus) and research controlling by microorganisms

In recent years, Neoscytalidium dimidiatum has caused severe white spot disease in Pytaya, while no effective controls have been taken. In this study, two strains of N. dimidiatum NdGV and NdBT were obtained by isolation on water agar medium containing streptomycin, morphological tests, in vitro and in vivo pathogenical tests, and molecular biology tests by sequencing the genes ITS1 and ITS4. By using dual culture technique on potato-glucose agar medium, 100% of Trichoderma spp., 75% of Bacillus spp. and 20% of Streptomyces spp. were able to antagonize N. dimidiatum. The mean antagonistic effect with N. dimidiatum of Trichoderma spp. was higher than Bacillus spp. and the lowest was Streptomyces spp. 56.8%, 55.3% and 54.3% respectively. Especially 5 strains Trichoderma sp. 8.3.5, 8.3.7, 8.3.14, 8.3.19, and 8.3.20 had antagonistic effects of over 60%. The application potential of the 5 selected Trichoderma strains to control N. dimidiatum disease was further strengthened when their antagonistic effect was relatively stable on Pitaya juice agar medium while all Bacillus sp. and Streptomyces sp. were lost the ability to antagonize. It was noteworthy that four of the five strains of Trichoderma sp. were highly compatible, suggesting further studies are needed to apply their combined potency in enhancing the control of N. dimidiatum NdBT and NdGV on Pitaya.

Вплив температури на ріст та розвиток гриба Diaporthe (Phomopsis) helianthi M.

The main condition for successful plants cultivation is their ability to adapt to a complex of environment factors. Climatic parameters (temperature, precipitation, humidity of air) takes a significant role in formation of soil processes, since water-air and thermal regimes of the soil, and, accordingly, the direction of biological processes are closely linked with them. In order to successfully grow sunflower Helianthus annuus L. it is necessary to know features of development most dangerous diseases – Phomopsis helianthi Munt , development of which depends on climatic conditions of the region and technology of growing this crop. In this regard, it is relevant to determine the optimal temperatures that contribute to development of Phomopsis helianthi Munt. on sunflower, annually in the Southern region ofUkraine. Under natural conditions, mushrooms are able to adapt to changes in environmental factors. Special effects on growth and development of the fungus are caused by temperature conditions that have a seasonal and daily fluctuation pattern. Therefore, there is a need to determine the most favorable and critical temperatures for development certain types of given pathogen in laboratory conditions in vitro . The aim of study was to determine the effect of temperature on growth and development of Diaporthe (Phomopsis) helianthi M. The isolation of Phomopsis helianthi M. in a pure culture and its identification was carried out at department of the Kherson regional phytosanitary laboratory. Potato glucose agar (PGA) was used in pure culture to isolate Phomopsis helianthi M. For inoculation of substrates, were used 2 weeks age cultures. The mycelium was sown in Petri dishes to the center surface of a dense nutrient agar with a small piece of the inoculum, about 5 ×5 mm in size, always of one density and age. Petri dishes were incubated in a thermostat with temperature of 0 °C; +5; +10; +15; +20; +25; +30 and +35 °C. It has been established that in culture vegetative growth of fungus Diaporthe (Phomopsis) helianthi M. occurs in a wide range of temperatures. Differences in the rate of mycelia growth are determined. The lower limit, which marked the growth of mycelium, is +5 °C, and the higher – + 30 °C. The temperature of 0 and + 35 °C did not reveal a growth of mycelium. In vitro, the least intense growth of the fungus culture was detected under temperature conditions of +5 °C and +10 °C. The beginning of Phomopsis helianthi M. growth occurred at 5 and 4 days, respectively. More intense of mycelium growth was noted for temperature regimes of +15 °C and + 20 °C. It has been shown that optimal temperature for isolates of Diaporthe (Phomopsis) helianthi growth is + 25 °C. Under these conditions, on the 8th day of incubation, complete colonization of the substrate in the Petri dish was recorded. After increasing temperature to + 30 °С, the intensity of growth of mycelium of the fungus decreased. Thus, the average monthly air temperature in the summer (20–23.8 °С) simultaneously with irrigation can contribute development of Diaporthe (Phomopsis) helianthi M. fungus on sunflower plants.

ИСПОЛЬЗОВАНИЕ ПОЧВООБИТАЮЩИХ БАКТЕРИЙ ДЛЯ ЗАЩИТЫ САХАРНОЙ СВЕКЛЫ ОТ КОРНЕВЫХ ГНИЛЕЙ

In the recent years, the use of soil microorganisms has generated great interests in crop production by reducing the damage of diseases. Actualite.The application of PGPR bacteria makes possible to improve the quantity and quality of plant s harvest and to reduce chemical pressure on the environment. The aim of investigations - study of the ability of the soil saprophytic diazotrophs bacteria (PGPR) reducing the infectious background of root rot diseases. deposited in the National Collection of nonpathogenic microorganisms of Moldova - Peudomonas aureofaciens CNMN-PsB-05, Pseudomonas fluorescens CNMN-PsB-04, Pseudomonas putida-PsB-06, Bacillus subtilis CNMN-bB-08. Materials. The agents pathogens from the beet tuber were isolated on potato-glucose agar and were identification as Fusarium oxysporum and Fusarium gibbosum, They reduce the shoots of beet seeds for 60-75%. The ability for antagonism strains Peudomonas aureofaciens CNMN-PsB-05, Pseudomonas fluorescensCNMN-PsB-04, Pseudomonas putida - PsB- 06, Bacillus subtilis CNmN-BB-08, deposited in the National Collection of nonpathogenic microorganisms of Moldova was defined in laboratory tests. Results. The suspension of bacterial strains with titre 108 CFU/ml show the antagonism in vitro toward the fitopathogens in time cultivation combine in Petri plates: the radius of delay growth Fusarium spp. were establish. Traitment of beet seeds, inoculate with pathogens, in time sowing with bacterials suspensions decreased the level of infection from agents pathogens of root rot, increased the shoots of beet seeds for 20-30%, the weight of tuber in 2.2 4,0 one and improved production of plants.

Ріст та розвиток гриба Phomopsis Helianthi M. на різних живильних середовищах

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

Вплив температури на ріст і життєздатність міцелію штамів мікофільного гриба Cladobotryum dendroides

У статті представлені результати досліджень впливу різних значень температур (від 18±0,3°С до 45±0,3°С) на швидкість росту, морфологію колоній та життєздатність міцелію 5 штамів Cladobotryum dendroides, що виділені з уражених павутинною цвіллю плодових тіл їстівного гриба Agaricus bisporus. Установлено, що оптимальною температурою для всіх штамів на картопляно-глюкозному агаризованому середовищі була 25±0,3°С. Збільшення температури на 6°С (с 25±0,3°С до 31±0,3°С) спричинило значне зменшення швидкості росту – для різних штамів – у 65–120 разів. Зниження температури на 7°С (с 25±0,3°С до 18±0,3°С) не настільки негативно вплинуло на швидкість росту досліджених штамів – цей показник знизився в 3–5 разів, порівняно зі швидкістю росту при оптимальній температурі. Установлено, що температура 35±0,3°С була критичною для росту міцелію трьох із 5 досліджених штамів, а для двох інших штамів значення критичної температури було на 1°С нижче й становило 34±0,3°С. Продемонстровано, що міцелій жодного з досліджених штамів C. dendroides не ріс при температурах -18±0,3°С, 5±0,3°С і 15± 0,3°С. Однак при перенесенні культур в умови оптимальної температури ріст відновився. Швидкість росту при цьому незначно відрізнялася від відповідних ростових показників штамів, культивованих при оптимальній температурі. Отже, показники температур -18±0,3°С, 5±0,3°С та 15±0,3°С спричиняють фунгістатичну дію на ріст міцелію досліджених штамів C. dendroides. У результаті дослідження впливу температури на морфологічні особливості росту міцелію штамів C. dendroides установлено, що при підвищенні температури інкубації (30±0,3°С, 31±0,3°С, 34±0,3°С) колонії всіх штамів набувають характерних морфологічних ознак: край колонії стає нерівним, колір колонії змінюється з блідо-жовтого або жовтого на рожевий, темно-бурий чи темно-вишневий, реверзум змінює колір із жовтого на темно-бурий або темно-вишневий.

DISCOVERY OF ENTOMOPATHOGENIC FUNGI Cordyceps takaomontana AT LANGBIAN MOUNTAIN, LAM DONG, VIET NAM

The stromata of Cordyceps sp. were found on the Langbian Mountain – Da Lat, Vietnam at the height of 1.650 meter above sea level, on the larva of Lepidoptera. Stromata were lemon-yellow, clavate to elongated clavate, arising from a white pseudosclerotium. The fertile head was on the top part of stromata, darker coloured in comparison to the stipe. Perithecium was narrowly ovoid, superficial and forming dark yellow punctate on the surface of stromata. Ascus cylindrical with semi- spherical cap. Ascospores were cylindric, truncated and separately after discharge from the ascus.Pure culture was isolated on Potato Glucose Agar (PGA) medium: white colony in young and yellow in old. The isolated mycelium was not homogenous in thickness and in growth rate at the peripheral area. Conidiophores were phialide, tapering to both apexes. Conidia had elliptical shape and form into chains after maturation.DNA was isolated, then purified from pure mycelium and used to amplifying the nrLSU (nuclear ribosomal large subunit) sequence. The amplified products were used for sequencing, proof-reading by some professional solfwares before combining with other nrLSU sequences. Then this database was used to search for the suitable evolution model as well as to construct the phylogenetic trees.The results of phylogenetic analysis completely supported the morphological classification: DL0038A and DL0038B were Cordyceps takaomontana.

Identification of Optimal Culture Conditions for Mycelial Growth and Cultivation of Monkey Head Mushrooms (Hericium erinaceus (Bull.: fr.) Pers)

Monkey head mushrooms (Hericium erinaceus (Bull.: Fr.) Pers) have been broadly cultivated and widely consumed as traditional medicinal herbs as well as functional food in the Orient for several hundred years of history. The identification of optimal culture conditions for mycelium growth and fruiting body formation is one of the most important steps in cultivation of mushroom. The aim of this study was to investigate the optimal culture conditions including pH level, temperature, media and substrate mixtures for the mycelium growth  and cultivation of Hericium erinaceus strain He-2. Results of the study revealed that the optimal conditions for mycelial growth were observed at 25 ± 1oC and pH 8.0. H. erinaceus was cultured on five different types of culture media: Czapek, Raper, PGA (potato, glucose, agar), PGA supplemented with rice bran, and PGA supplemented with fresh mushrooms. PGA supplemented with fresh mushrooms was found to be the best medium for the growth of mycelia. A media containing 99% grain of rice + 1% CaCO3 was considered as the best mother spawn media for mycelial growth. Among various culture media, the highest mycelium growth rate and biological efficiency of H. erinaceus were obtained when grown on a treatment of 87% sawdust + 4% corn bran + 8% rice bran + 1% CaCO3.

Detection of Oil Palm Root Penetration by Agrobacterium-Mediated Transformed Ganoderma boninense, Expressing Green Fluorescent Protein.

A highly efficient and reproducible Agrobacterium-mediated transformation protocol for Ganoderma boninense was developed to facilitate observation of the early stage infection of basal stem rot (BSR). The method was proven amenable to different explants (basidiospore, protoplast, and mycelium) of G. boninense. The transformation efficiency was highest (62%) under a treatment combination of protoplast explant and Agrobacterium strain LBA4404, with successful expression of an hyg marker gene and gus-gfp fusion gene under the control of heterologous p416 glyceraldehyde 3-phosphate dehydrogenase promoter. Optimal transformation conditions included a 1:100 Agrobacterium/explant ratio, induction of Agrobacterium virulence genes in the presence of 250 μm acetosyringone, co-cultivation at 22°C for 2 days on nitrocellulose membrane overlaid on an induction medium, and regeneration of transformants on potato glucose agar prepared with 0.6 M sucrose and 20 mM phosphate buffer. Evaluated transformants were able to infect root tissues of oil palm plantlets with needle-like microhyphae during the penetration event. The availability of this model pathogen system for BSR may lead to a better understanding of the pathogenicity factors associated with G. boninense penetration into oil palm roots.

THE STUDY OF THE CULTURAL- MORPHOLOGICAL FEATURES OF PHYTOPATHOGENIC FUNGUS ACREMONIUMSP. 502

The paper provides the description of cultural-morphological features of phytopathogenic fungus Acremonium sp. 502 belonging to the group of slow-growing bacteria. The highest radial growth rate was achieved on a potatoglucose agar (0.1375 ± 0.0011 mm/h); the optimum medium pH was 8.5; the optimum temperature — 26 °C.

Bffects of foliar fungicides on the mycoflora of glumes of Triticum aestivum

In the years 1983-1984. the effect of three foliar fungicides, i.e.. Bayleton 25 WP. Dithane M-45 and Funaben K on the mycoflora associated with glumus of spring <i>Tritieum aestivum</i> cv. Kolibri cultivated in the field was investigated. During each vegetative period, glumes were collected in the milky ripe of seeds. Fungi species associated with glumes were determined based of colonies isolated from glumes incubated in Petri dishes with potato glucose agar. The fungicide which reduced the most the overall number of fungal isolates was Bayleton 25 WP. The number of species was most reduced following Dithane M-45 application. The mycoflora of glumes which had been untreated and treated with fungicides was compared with fungicides-treated and fungicide-untreated seeds and leaves. The highest similarity in the mycoflora of fungicide-untreated plant parts was found when glumes and seeds were compared. The mycoflora of fungicide-treated glumes, leaves, and seeds varied. depending on the year and fungicide applied.

Biotic effects of mycoflora of leaves, glumes and seeds on Septoria nodorum foliowing Triticum aestivum treatment with fungicides

Using a biotic series method, interactions between <i>Sepfona nodorum</i> and associated fungal communities isolated from leaves, glumes, and seeds of spring <i>Triticum acstivum</i>. cv. Kolibri treated with Bayleton 25 WP. Dithane M-45. and Funaben K were determined. Control planls were sprayed with water. Most fungi accompanying <i>S. nodorum</i> in the field inhibited the growth of this pathogen on a potato glucose agar medium. Fungi which restricted the growth of <i>S. nodorum</i> the most were <i>Chaetomium globosum, Fusarium</i> spp., <i>Helminthosporium sativum, Mucor hiemalis, Rbizophus nigrieans, Stemphylium botryosum, Trichothecium roseum</i>, and two non-sporulating forms. <i>Septoria nodorum</i> replaced <i>Cladosporium</i> spp. and a yeast-like pink fungus. The biotic resistance to <i>S. nodorum</i> increased with me age of plant. The fungal populations recovered from plants sampled in 1982 and 1983 inhibited the growth of <i>S. nodorum</i> whereas most of those isolated in the relatively wet and cold year 1984 favoured the development of this pathogen, The lowest biotic resistance of the fungal communities investigated to <i>S. nodorum</i> was generally found following spraying of plant s with Bayleton 25 WP, and ihe highest in Funabed K - and water-treated plants.

Diversity and Antimicrobial Activity of Culturable Fungi Isolated from Six Species of the South China Sea Gorgonians

Fungi in gorgonians are now known to cause gorgonian diseases, but little attention has been paid to the nature of fungal communities associated with gorgonians. The diversity of culturable fungi associated with six species of healthy South China Sea gorgonians were investigated using a culture-dependent method followed by analysis of fungal internal transcribed spacer sequences. A total of 121 fungal isolates were recovered and identified using the Basic Local Alignment Search Tool search program. These belonged to 41 fungal species from 20 genera. Of these, 30 species and 12 genera are new reports for gorgonians, and the genera Aspergillus and Penicillium were the most diverse and common in the six gorgonian species. Comparison of the fungal communities in the six gorgonian species, together with results from previous relevant studies, indicated that different gorgonian species and the same gorgonian species living in different geographic locations had different fungal communities. The gorgonian Dichotella gemmacea harbored the most fungal species and isolates, while Echinogorgia aurantiaca had the least fungal diversity. Among the six media used for fungal isolation, potato glucose agar yielded the highest isolates (27 isolates), while glucose peptone starch agar had the best recoverability of fungal species (15 species). The antimicrobial activity of the 121 fungal isolates was tested against three marine bacteria and two marine gorgonian pathogenic fungi. A relatively high proportion (38%) of fungal isolates displayed distinct antibacterial and antifungal activity, suggesting that the gorgonian-associated fungi may aid their hosts in protection against pathogens. This is the first report comparing the diversity of fungal communities among the South China Sea gorgonians. It contributes to our knowledge of gorgonian-associated fungi and further increases the pool of fungi available for natural bioactive product screening.

Comparative study of the biological characteristics between <I>Alternaria alternata</I> and <I>Alternaria tabacina</I>

Comparative study of biological characteristics between Alternaria alternata and Alternaria tabacina were carried out.The results showed that the optimal growth temperature for Alternaria alternata and Alternaria tabacina were 25?30 ℃ and 20?25 ℃ respectively;A.alternata grew better than A.tabacina at pH 6?9;glucose and sugar utilization of A.alternata was higher than that of A.tabacina;the same results were got for the use of acmonium nitrate,acmonium sulfate and casein by Alternaria alternata and Alternaria tabacina.Both organisms showed the highest utilization of casein,followed by acmonium nitrate and acmonium sulfate.There were significant differences in mycelia growth of Alternaria alternata and Alternaria tabacina on potato agar,glucose agar and sugar agar respectively,while no differences existed between that of Alternaria alternata and Alternaria tabacina on cornmeal agar.Iprodione and Mancozeb totally inhibited the growth of A.alternata and A.tabacina.No difference existed in the inhibitive effects of chlorothalonil or stroby on A.alternata and A.tabacina while Topsin-M showed better inhibition on the mycelia of A.tabacina than that of A.alternata.

Methods for Detection ofAlternaria padwickiiin Rice Seeds

AbstractThe fungusAlternaria padwickiihas been frequently detected in seed tests of rice collected from commercial crops in Corrientes Province, Argentina. This pathogen causes germination inhibition, seedling death or spotted grains and is the causal agent ofAlternarialeaf spot. The pathogen survives as mycelia and sclerotia on seeds, plant debris and soil. Four detection methods were compared in laboratory tests, to select the best for a quick identification of the fungus in seeds. The methods were (i) Blotter Test (ii) Potato glucose agar, (iii) Bean agar (BA) and (iv) Malt extract agar. Twenty seed samples of different varieties of rice collected from Empedrado, Goya, Itá Ibaté, La Cruz, Mercedes, Paso de los Libres and Perugorría localities (Corrientes, Argentina), were analyzed in the assays. Theanovatest and the Tukey multiple range test were applied on the data to compare theA. padwickiiincidence among the varieties and detection methods. BA method was found more sensitive than other methods forA. padwickii. The incidence values ranged from 3.6 to 76%. The statistical analysis demonstrated that the BA method was the most efficient for the detection of seed pathogens, and it could be useful in studies of transmission and chemical control.