MEA Medium Research Articles

IN-VITRO ANTAGONISM EXPERIMENT OF Trichoderma spp. TO Ganoderma sp. WHICH ATTACKS SENGON TREES

Ganoderma sp. is a pathogenic fungus that can cause root rot in sengon ( Falcataria mollucana ) plantation. Ganoderma sp. is difficult to detect because the symptoms are simillar to symptoms of other root diseases. The experiment was conducted at the Laboratory of the Faculty of Forestry IPB with aims to determine in vitro growth rate of colony diameter of Ganoderma sp. and Trichoderma spp. and also to obtain the ability of Trichoderma spp. in inhibiting the growth of colonies of isolates of Ganoderma sp. on PDA and MEA medium. The result shows that diameter of colony isolat Ganoderma sp. growth on PDA media (7,09 mm/day) was faster than the growth on MEA media (5,41 mm/day). The growth rate of the colony diameter of Trichoderma spp. isolates on PDA were 69,67 mm/day, 56.49 mm/day, and 42,04 mm/dayfor T.viride , T.harzianum and T.pseudokoningii , respectively. While, using the MEA media obtained an average value of growth of diameter colony isolates were 77,29 mm/day, 66,50 mm/day, and 59,67 mm/day ) for T.pseudokoningii , T.harzianum and T.viride , respectively. The highest percentage of inhibiting barriers of Trichoderma spp. was T.harzianum than T.pseudokoningii (59,76%) and T.viride (46,47%).

Pinus sylvestris Can Form Ectomycorrhiza with Phialocephala fortinii

The ectomycorrhizal fungal community associated with Pinus sylvestris (Scots pine) in a Mongolian forest was investigated in this study. The fungal strain was isolated from roots of Scots pine and identified as Phialocephala fortinii. Inoculation experiments showed that Phi. fortinii could form ectomycorrhizae with Scots pine seedlings. Hartig nets, external hyphae, and mantle structures of ectomycorrhizae were observed in pine seedlings roots. The morphology and ultra-structure of the fungal-host plant association and characteristics of Phi. fortinii colonies developed on MEA, MMN, and PDA media are described. Phialocephala fortinii inoculation significantly increased the growth, biomass accumulation, and P, K, Ca, Mg, Na, and N concentrations in roots, stems, and needles of pine seedlings. These results demonstrated that Phi. fortinii could effectively form ectomycorrhizae with Scots pine and improve its growth, presumably through enhanced nutrition acquisition.

Cultural characteristics and pathogenicity of Pestalotiopsis funerea on Cupressus arizonica

SummaryThe fungal pathogen Pestalotiopsis funerea principally attacks conifer species, causing necrosis on infected tissues, and sometimes death of plants. The main objectives of this study were to determine optimal in vitro growth conditions for Spanish isolates of P. funerea and to evaluate the virulence of these isolates on Cupressus arizonica under field and laboratory conditions, with the goal of verifying possible correlations between these variables. Eight isolates of P. funerea derived from C. sempervirens, C. arizonica and Quercus pyrenaica were used in the assays. In the growth rate experiment, five culture media (PDA, MEA, WA, PCA and TAKAY medium) and six temperatures (5, 10, 15, 20, 25 and 30°C) were evaluated. In the pathogenicity tests, two different experiments were carried out: (i) laboratory inoculations used 30‐mm‐long twigs of C. arizonica; (ii) in field inoculations, twigs of C. arizonica were inoculated with mycelia through wounds. Four months after inoculation, length of the twigs affected by necrosis were measured. The results suggested that Spanish P. funerea isolates had optimum growth at 25°C on TAKAY medium. The fungus caused substantial necroses on C. arizonica twigs after inoculation in both excised twigs and on adult C. arizonica trees. A positive relationship between inoculations carried out under laboratory and field conditions was found. No clear relationships were found between cultural characteristics and pathogenicity for P. funerea.

Isolation of Paecilomyces lilacinus (Thom) Samson (Ascomycota: Hypocreales) from the Chagas disease vector, Triatoma infestans Klug (Hemiptera: Reduviidae) in an endemic area in Argentina

A survey for entomopathogenic fungi of the Chagas disease vector Triatoma infestans was conducted in two provinces of Argentina from March-December 2003. Field-collected insects that died in the laboratory were individually maintained in moist chamber and incubated at 22 degrees C. Triatominae adults infected with the fungus Paecilomyces lilacinus were found at El Quebracho (27 degrees 34'S-64 degrees 31'W), Santiago del Estero province, Argentina, in December 2003. Paecilomyces lilacinus was cultured and isolated from infected insects in SDAY, PYG and MEA media. Pathogenicity tests were conducted and positive results were recorded. The median survival time (MST) of T. infestans exposed to a P. lilacinus conidial suspension was 12.8 days, and 100% mortality occurred at 30 days post-treatment. This is the first record of natural infection caused by P. lilacinus in T. infestans in the world.

Basidiomatal formation of Antrodia cinnamomea on artificial agar media

Basidiomes of Antrodia cinnamomea are used as a traditional medicine in Taiwan. Because fungal basidiomes are so rare and attempts to cultivate them have failed, the price they command in the marketplace is exorbitant. Here, one dikaryotic isolate from a pairing between two compatible monokaryons obtained from two different basidiomes was able to produce basidiomes on PDA and MEA media at temperatures of 20-28°C within 45 days of incubation. The basidia and basidiospores produced on the hymenial layer were microscopically observed.

Técnica de restrição hídrica: efeito sobre Acremonium strictum, protrusão de sementes e obtenção de sementes de milho infetadas

Este experimento objetivou a obtenção de sementes de milho (Zea mays) portadoras de Acremonium strictum, utilizando-se técnica de restrição hídrica e visando sua utilização posterior em estudos sobre a interação patógeno - hospedeiro. O trabalho constou de avaliações de efeitos da adição de manitol, NaCl e KCl nos potenciais de -0,48; -0,6; -0,8; -1,0; -1,2 e -1,4 MPa ao meio extrato de malte-ágar (MEA) sobre o crescimento micelial, textura de micélio, forma marginal da colônia, pigmentação e esporulação in vitro de colônias de A. strictum, bem como sobre o percentual de protrusão de radículas de sementes de milho. Foi avaliada também a correlação entre diferentes períodos de exposição das sementes à colônia do fungo e sua incidência em sementes desinfestadas ou não com NaClO 1% por 2 min. A taxa de crescimento micelial de A. strictum foi estimulada em meio MEA + manitol (-0,6 a -1,4 MPa) e a morfologia típica de colônias do patógeno em meio MEA acrescido com manitol, NaCl e KCl diferiu dos padrões apresentados no controle (-0,48 MPa). A esporulação do fungo foi estimulada pelo manitol nos potenciais -0,8 a -1,4 MPa, aplicados ao meio de cultivo padrão. As menores percentagens de protrusão radicular em sementes de milho incubadas por até cinco dias foram observadas em MEA + manitol (-1,4 MPa) e MEA + NaCl (-1,2 e -1,4 MPa). No entanto, verificou-se efeito fitotóxico do NaCl sobre a germinação das sementes. Por meio da técnica de restrição hídrica foi possível obter até 36% de sementes de milho infetadas por A. strictum.

Test of Populus x euramericana cv. Pannònia resistance to the attack of Discoporium populeum (Sacc) Sutton by artificial infections

Populus x euramericana cv. Pann?nia is an artificial hybrid, created in the Sarvar research station (Hungary), by crosses made by Kopecky Ferenc. It was registered in Hungary and its identification is H 490-31. Its parents are: Populus deltoides S-1-54 & Belgium (P. deltoides A 42 Iowa ? P. deltoides A148 Missouri) x P. nigra L?b?ny 211%. Inoculations were implanted by spore suspension and mycelium of the fungus, grown on the MEA medium, by standard method. The experiments were performed on the plants 1/2, especially singled out for the experiment and on the plants in the second year after transplanting (2/2 and 2/3), at the locality Siget. The inoculations were replicated three times: 15.05.2000, 14.10.2000 and 31.03. 2001 The study shows that the newly introduced cultivar Populus ? euramericana cv. Pann?nia is not immune to the attack of the fungus Discosporium populeum. The highest percentage of realised infections in the experiment with mycelium was realised in October (89.7%), and the lowest percentage in May (22.6%). Inoculations with spore suspension had the same trend, only the percentage of realised infections was considerably lower, with the maximal value for October, 23.5%. Infection with spore suspension implanted in leaf scar produced the positive results, with 10.4% percentage of infection. A very significant fact is that the percentage of random infections of the plants monitored during the experiment was only 4.4%. Only one plant was girdled and killed during the research. It must be emphasised that all the necrotised spots were callused and remedied in a short period after infection, which indicates the presence of the defence mechanisms in this cultivar The study results are a good base of further research. To be able to bring correct conclusions and recommendations to the practice regarding this cultivar in the study area, it is necessary to assess the degree of Discosporium populeum presence on one-year and two-year old trees .

Effect of Three Different Culture Media on Mycelial Growth of Oyster and Chinese Mushrooms

The sporocarps obtained from NARC, Islamabad and local market were utilized as a source of tissue culturing. Initial culturing was done on malt extract agar plates. The discs (0.5 cm in diameter) from actively growing culture plates of three different mushrooms were planted on the fresh media plates of Malt extract agar medium (MEA), Murashige and Skoog's (MS) medium and potato dextrose agar (PDA) medium. Three replicates were taken in each case. An increase in diameter of the culture discs was recorded daily. The results indicted that the mycelial growth of Pleorotus ostreatus, varieties sajar, caju, citydeosus and Volvariella volvacea were maximum in medium plates containing MEA medium. The results were significant at P = 0.05 level of significance. While potato dextrose agar medium (PDA), ended up with slowest growth.

Paecilomyces cateniannulatus Liang, a commonly found, but an unrecorded entomogenous fungus in Japan.

Cultural and morphological characters of isolates belonging to an entomogenous Paecilomyces species commonly found in Japan were investigated and compared with the literature. This species has not been recorded in major monographs of this genus, but identified as Paecilomyces cateniannulatus Liang described in 1981 from China. Mycelia on insects and media were pure white, and sometimes produce loose synnemata up to 10 mm. Growth rate of the fungus is moderate. The reverse side of colonies on SDY or MEA media are colorless to light yellow. Phialides are flask shaped with a narrow neck, 3.0–16.1×1.3–3.2 μm, often forming a whorl. Conidia are oval to short cylindrical, 2.1– 4.6×1.3–2.4 μm, arranged in basipital chains. Conidial chains are often irregularly curved and sometimes form a loop. Early stage of the conidiogenous structure of this fungus resembles that of Beauveria, but is distinguished by formation of conidial chains.

Effects of temperature and light on growth and sporulation of aquatic hyphomycetes

Nine isolates of the aquatic hyphomycetes Dactylella aquatica, Flagellospora penicillioides, Flagellospora saccata, Helicomyces sp., Lunulospora curvula, Phalangispora constricta, Tetracladium setigerum, Vermispora cauveriana and Wiesneriomyces laurinus were incubated at different temperatures (5–35 °C) to study their growth on MEA medium. Maximum growth was observed between 20 and 30 °C. Growth rate was highest in Vermispora cauveriana and lowest in Tetracladium setigerum. Colonies on submerged leaves showed maximum spore production at 25 °C. Light was confirmed as a stimulus to sporulation.

Serotypes and mating types of clinical strains ofCryptococcus neoformans isolated in Taiwan

Twenty-one strains of Cryptococcus neoformans isolated from patients in Taiwan were characterized for serotypes and mating types. Slide agglutination test was performed with 8 factor-specific sera (Iatron Company, Japan) to determine the serotypes. Wheat bran agar (WBA) and malt extract agar (MEA, Wickerham) media were used for the mating tests. Twenty of the isolates were of serotype A, and one was serotype B. Except for 2 strains of serotype A, all of the serotype A strains mated with Filobasidiella neoformans var. neoformans, mating type a. The only serotype B strain mated with F. neoformans var. bacillispora mating type a in MEA medium. These data revealed the low prevalence (1/21; 4.8%) of C. neoformans var. gattii in Taiwan, a subtropically located isoland.