Growth of Wallrothiella arceuthobii on artificial media

1970 ◽  
Vol 48 (5) ◽  
pp. 837-838 ◽  
Author(s):  
A. K. Parker
Keyword(s):  
Yeast Extract ◽  
Ascospore Germination ◽  
Germination And Growth

Ascospore germination and growth of Wallrothiella arceuthobii (Peck) Sacc. on artificial media is reported. Germination was enhanced by yeast extract or by increasing the agar content of media. Yeast extract was required to sustain growth.

scholarly journals Survival, Germination, and Growth of Epichloë typhina and Significance of Leaf Wounds and Insects in Infection of Orchardgrass

Plant Disease ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 323-328 ◽  
Author(s):  
Stephen C. Alderman
Keyword(s):  
Water Potential ◽  
Infection Process ◽  
Effect Of Temperature ◽  
Ascospore Germination ◽  
Eriophyid Mites ◽  
Epichloë Typhina ◽  
Dry Conditions ◽  
Significant Yield ◽  
Germination And Growth ◽  
Germ Tubes

Epichloë typhina is an important stroma-producing endophytic ascomycete that is responsible for significant yield loss in orchardgrass (Dactylis glomerata) seed production fields. Infection is presumed to occur through leaves or stems, although details of the infection process and conditions that favor leaf infection are not well understood. The primary objectives of this study were to investigate the early stages of infection, including the effect of temperature or water potential on ascospore germination and subsequent growth of E. typhina, the tolerance of ascospores to desiccation, the requirement of leaf wounds for infection of orchardgrass by E. typhina, and the potential for insects to facilitate infection. Ascospores tolerated dry conditions, with at least 40% surviving 12 days under desiccation. Germination and growth of E. typhina was greatest at 25°C, with little to no growth at 5 and 35°C. Mycelial growth decreased with decreasing water potential from –0.3 to –10 MPa. Ascospore germination on leaves was predominantly hyphal at wound sites and iterative (conidiogenous) at sites without wounds. E. typhina typically entered leaves through wounds. Direct penetration was rarely observed and appeared to be associated with ascospore clusters. Germ tubes were significantly longer at sites with honeydew deposits from the bird cherry–oat aphid than at sites without honeydew. Growth of E. typhina was also observed at feeding sites of eriophyid mites, suggesting that leaf-wounding or sap-excreting insects support epiphyllous growth of E. typhina on leaves.

The development and growth requirements of Dactylorhiza purpurella in asymbiotic cultures

1972 ◽  
Vol 50 (6) ◽  
pp. 1223-1229 ◽  
Author(s):  
Gaëtan Harvais
Keyword(s):  
Yeast Extract ◽  
Growth Regulators ◽  
Culture Media ◽  
Initial Period ◽  
Casein Hydrolysate ◽  
Growth And Survival ◽  
Beneficial Effects ◽  
Casamino Acids ◽  
The Right ◽  
Germination And Growth

Dactylorhiza purpurella was grown from seed in sterile cultures on agar slopes. The culture media consisted of combinations of minerals, dextrose or sucrose, the amino acids and vitamins etc. found in casein hydrolysate, and yeast extract. After an initial period of germination and growth, the cultures were treated with kinetin, kinetin riboside, 6(γ, γ-dimethylallylamino)purine, and indoleacetic acid (IAA), alone and in various combinations, primarily to simulate patterns of development previously obtained in symbiotic cultures.The results with dextrose and sucrose were essentially similar. Germination and growth in either case were markedly superior where casamino acids were present, and growth and survival were further improved with supplements of yeast extract to those media. On such media protocorm development was normal and in every respect as good as in symbiotic cultures. Aspartic, glutamic, and nicotinic acids appear to play vital roles in the nutrition of D. purpurella.The three aminopurines tested enhanced the shoot characters and suppressed the root characters of the protocorms, and enhanced chlorophyll formation. The results with IAA were inconclusive. The growth regulators may interact with aspartic and (or) glutamic acids with respect to morphogenesis.Iron (as ammonium ferric citrate) was deficient and limiting at 0.2 mg/liter Fe. Greener shoots, better rooting, and no harmful effects were obtained with 25 mg/liter. High levels of manganese (50 mg/liter) caused severe leaf chlorosis and hindered the beneficial effects of iron on the shoots. An Fe/Mn ratio greater than unity was necessary. Within certain limits, the right ratio may be more important than the actual levels of these cations.The effects of the growth regulators should be reassessed in relation to at least aspartic and glutamic acids, iron and manganese.

Effects of Potassium Sorbate on Growth and Ochratoxin Production by Aspergillus ochraceus and Penicillium Species1,2

1985 ◽  
Vol 48 (2) ◽  
pp. 162-165 ◽  
Author(s):  
LLOYD B. BULLERMAN
Keyword(s):  
Yeast Extract ◽  
Spore Germination ◽  
Mycelial Growth ◽  
The Other ◽  
Aspergillus Ochraceus ◽  
Potassium Sorbate ◽  
Penicillium Sp ◽  
Mycelial Mass ◽  
Germination And Growth ◽  
Yeast Extract Sucrose

Effects of potassium sorbate on growth and ochratoxin production by Aspergillus ochraceus NRRL 3174 and Penicillium sp. isolated from cheese were studied. Potassium sorbate at 0.05, 0.10 and 0.15% delayed or prevented spore germination and initiation of growth, and decreased the rate of growth of both organisms in yeast-extract sucrose (YES) broth at 12°C. However, at 25°C germination and growth of A. ochraceus was more rapid. Increasing concentrations of sorbate caused more variation in the amount of total mycelial growth of Penicillium sp. and generally resulted in a decrease in total mycelial mass. Potassium sorbate also greatly reduced or prevented production of ochratoxin by Penicillium sp. for up to 70 d at 12°C. At 0.05 and 0.10% sorbate, ochratoxin production was greatly reduced over the control, and was eliminated at 0.15%. Overall, ochratoxin production by Penicillium sp. in the presence of sorbate was very low or eliminated. On the other hand, A. ochraceus responded somewhat differently to sorbate. At 12°C, A. ochraceus was similarly inhibited by all three levels of sorbate, and did not produce ochratoxin. When incubated at 25°C, A. ochraceus grew quite readily and appeared to produce greater amounts of ochratoxin in the presence of sorbate, especially at the 0.05% level. Considerably higher levels of ochratoxin were produced at 0.05% sorbate than the control, and somewhat higher levels were obtained at 0.10 and 0.15% sorbate.

Growth requirements and development of Cypripedium reginae in axenic culture

1973 ◽  
Vol 51 (2) ◽  
pp. 327-332 ◽  
Author(s):  
Gaëtan Harvais
Keyword(s):  
Yeast Extract ◽  
Pantothenic Acid ◽  
Axenic Culture ◽  
Casein Hydrolysate ◽  
Stage Of Development ◽  
Thunder Bay ◽  
Terrestrial Orchids ◽  
Potato Extract ◽  
The Right ◽  
Germination And Growth

In preliminary studies of terrestrial orchids of the Thunder Bay region Cypripedium reginae showed greatest promise as a species for the investigation of the effects of temperature, light, and nutrients. The orchid was grown from seed in sterile cultures on agar slopes of media consisting of various combinations of minerals, sugars, casein hydrolysate, yeast extract, potato extract, the vitamins thiamine, pantothenic acid, and pyridoxine, and the aminopurines kinetin, kinetin riboside, 6(γ,γ-dimethylallylamino)purine, and zeatin.Better germination and growth occurred at 25 °C vs. 15 °C. Germination was better in the dark than in the light. The young protocorms are adversely affected by light until a crucial stage of development is reached. Premature exposure to light, even at the low intensity of 70 lm/ft2, caused mortality.There was no germination on sterile-distilled-water agar or on mineral media alone. Mineral–sugar media produced fairly healthy plantlets; better results were obtained with sucrose, dextrose, and fructose, respectively. Cypripedium reginae was highly intolerant of the casein hydrolysate and yeast extract supplements. Potato extract at 10% of the original concentration was very beneficial.In some cultures the presence of ammonium ions could be responsible for a marked enhancement of growth (and a slight stimulation of germination irrespective of the presence of sugar). The right nitrate/ammonium ratio may be critical. Low levels of nitrate or high levels of chloride or both hindered responses to iron supplements. Also, C. reginae may have a low calcium requirement.The effects of the three vitamins were restricted to the leaves, causing them to broaden to natural proportions while those in the controls remained spindly. Thus, C. reginae may be heterotrophic for those vitamins.There was no morphogenetic response to the four aminopurines. They impeded growth equally in the light as in the dark.

Low-temperature requirements for ascospore germination and growth of Hypoxylon diathrauston

1970 ◽  
Vol 48 (12) ◽  
pp. 2223-2225 ◽  
Author(s):  
G. B. Ouellette ◽  
E. W. B. Ward
Keyword(s):  
Low Temperature ◽  
Ascospore Germination ◽  
Temperature Requirements ◽  
Freezing Temperatures ◽  
Germination And Growth ◽  
Germ Tubes

Ascospores of Hypoxylon diathrauston Rehm germinated only at freezing temperatures or required pretreatments at −3 °C to enable them to germinate at 12 °C. They required from 10 to 30 days to germinate in our experiments. They germinated by two, but occasionally one, three, and even four, germ tubes growing through pores in the relatively thick inner wall at each end of the slit after its enlargement. Cultures grew at 0 °C with an optimum at 12–15 °C, and a maximum between 18 and 21 °C.

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