Taxonomic Studies on Australian Isolates of Stemphylium spp. And Associated Teleomorphs

1986 ◽  
Vol 34 (3) ◽  
pp. 281 ◽  
Author(s):  
JAG Irwin ◽  
R Dill-Macky ◽  
M Stirling
Keyword(s):  
Medicago Sativa ◽  
Pure Culture ◽  
Herbarium Specimens ◽  
Simmondsia Chinensis ◽  
Pure Cultures ◽  
Taxonomic Studies ◽  
Ascospore Morphology

Taxonomic studies on monosporic pure cultures of Australian isolates of Stemphylium revealed the presence of three species, namely S. botryosum, S. globuliferum and S. vesicarium. A group intermedi- ate between S. botryosum and S. vesicarium but more closely resembling S. vesicarium was recognised. The circumscription of S. vesicarium was broadened to accommodate this taxon which was found on Medicago sativa, M. rugosa and Simmondsia chinensis. Studies on herbarium specimens deposited as S. botryosum on M. sativa from a number of overseas locations indicated that in all cases the pathogen fitted our concept of S. vesicarium. Teleomorphs were induced in pure culture for each of the above-mentioned anamorphs, and in all instances the teleomorph was identified as Pleospora herbarum. The ascospore morphology was similar for all isolates, and the shape of the ends of the spore and the number of longitudinal septa were variable characters even within an isolate. However, the teleomorphs could be separated into two distinct groups on the basis of ascal length.

Taxonomic studies on the genus Delphinium (Ranunculaceae) from China (XXI): The identities of D. breviscaposum and D. filibracteolum from northwestern Yunnan

Phytotaxa ◽  
2019 ◽  
Vol 420 (2) ◽  
pp. 185-197 ◽  
Author(s):  
QIONG YUAN ◽  
QIN-ER YANG
Keyword(s):  
Type Material ◽  
Second Step ◽  
Herbarium Specimens ◽  
Taxonomic Studies ◽  
Northwestern Yunnan

Based on examination of herbarium specimens (including type material), we demonstrate that Delphinium breviscaposum and D. filibracteolum (Ranunculaceae), both described recently from northwestern Yunnan in China, are conspecific with D. ceratophorum and D. bulleyanum, respectively, two species very common in northwestern Yunnan. We therefore synonymize D. breviscaposum and D. filibracteolum herein. Second step lectotypifications are proposed for both D. bulleyanum and D. ceratophorum.

Effect of Enrichment Media and Sampling Protocol on Recovery of Listeria monocytogenes

1990 ◽  
Vol 53 (6) ◽  
pp. 505-507 ◽  
Author(s):  
J. S. BAILEY ◽  
D. L. FLETCHER ◽  
N. A. COX
Keyword(s):  
Listeria Monocytogenes ◽  
Pure Culture ◽  
Sampling Protocol ◽  
Enrichment Broth ◽  
Secondary Enrichment ◽  
Pure Cultures ◽  
University Of Vermont

These studies examined the differences in recovery of Listeria monocytogenes from pure culture and in the populations of mixed aerobic microflora from chicken and Brie cheese incubated in University of Vermont (UVM) and Listeria enrichment broth (LEB) enrichment broths for different times and conditions. No significant differences were observed in levels of L. monocytogenes from pure cultures in UVM or LEB on any sampling day. No differences were observed in the levels of mixed microflora from Brie cheese in either UVM or LEB, but from chicken rinse the level of mixed flora competitors was significantly higher on all sampling days in LEB as compared to UVM. No differences were observed between a single enrichment in UVM or LEB for 2 d and a transfer to a secondary enrichment tube after 1 d. Overall, the level of mixed microflora capable of growing in enrichment broths was greater from chicken rinse than from Brie cheese. The ratio of L. monocytogenes to mixed microflora which survived the selective enrichments was most favorable for recovery of L. monocytogenes after 2 d of enrichment.

Nitrogen fixation by subterranean clover (Trifolium subterraneum L.) growing in pure culture and in mixtures with varying densities of lucerne (Medicago sativa L.) or phalaris (Phalaris aquatica L.)

1999 ◽  
Vol 50 (6) ◽  
pp. 1047 ◽  
Author(s):  
B. S. Dear ◽  
M. B. Peoples ◽  
P. S. Cocks ◽  
A. D. Swan ◽  
A. B. Smith
Keyword(s):  
Medicago Sativa ◽  
N2 Fixation ◽  
Pure Culture ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Shoot Biomass ◽  
N Fixation ◽  
Mineral N ◽  
Phalaris Aquatica ◽  
Medicago Sativa L

The proportions of biologically fixed (Pfix) plant nitrogen (N) and the total amounts of N2 fixed by subterranean clover (Trifolium subterraneum L.) growing in pure culture and in mixtures with different densities (5, 10, 20, or 40plants/m2) of newly sown phalaris (Phalaris aquatica L.) or lucerne (Medicago sativa L.) were followed over 3 years in a field study using the 15N natural abundance technique. The amount of fixed N in subterranean clover was linearly related to shoot biomass. Over the 3-year period, subterranean clover fixed 23–34 kg N/t shoot biomass compared with 17–29 kg N/t shoot biomass in lucerne. Based on above-ground biomass, pure subterranean clover fixed 314 kg N/ha over the 3 years compared with 420–510 kg N/ha by lucerne–clover mixtures and 143–177 kg N/ha by phalaris–clover mixtures. The superior N2 fixation by the lucerneŒsubterranean clover mixtures was due to the N fixed by the lucerne and the presence of a higher subterranean clover biomass relative to that occurring in the adjacent phalaris plots. In the first year, 92% of subterranean clover shoot N was derived from fixation compared with only 59% of lucerne. The reliance of clover upon fixed N2 remained high (73–95%) throughout the 3 years in all swards, except in pure subterranean clover and lucerne in August 1996 (56 and 64%, respectively). Subterranean clover usually fixed a higher proportion of its N when grown in mixtures with phalaris than with lucerne. The calculated Pfix values for lucerne (47–61% in 1995 and 39–52% in 1996) were consistently lower than in subterranean clover and tended to increase with lucerne density. Although lucerne derived a lower proportion of its N from fixation than subterranean clover, its tissue N concentration was consistently higher, indicating it was effective at scavenging soil mineral N. It was concluded that including lucerne in wheat-belt pastures will increase inputs of fixed N. Although lucerne decreased subterranean clover biomass, it maintained or raised Pfix values compared with pure subterranean clover swards. The presence of phalaris maintained a high dependence on N2 fixation by subterranean clover, but overall these swards fixed less N due to the lower clover herbage yields. Perennial and annual legumes appear compatible if sown in a mix and can contribute more N2 to the system than where the annual is sown alone or with a perennial grass. These findings suggest that increases in the amount of N2 fixed can be achieved through different legume combinations without interfering greatly with the N fixation process. Different combinations may also result in more efficient use of fixed N2 through reduced leaching. Further work looking at combinations of annuals possibly with different maturity times, different annual and perennial legume combinations, and pure combinations of perennial (e.g. lucerne) could be investigated with the aim of maximising N2 fixation and use. Grazing management to encourage clover production in mixtures with phalaris will be necessary before the potential of subterranean clover to contribute fixed N2 in these swards is fully realised.

Taxonomic studies on the genus Delphinium (Ranunculaceae) from China (XX): Reduction of D. ellipticovatum and D. tianshanicum to the synonymy of D. winklerianum

Phytotaxa ◽  
2019 ◽  
Vol 405 (1) ◽  
pp. 37
Author(s):  
HUI-MIN LI ◽  
QIONG YUAN ◽  
QIN-ER YANG
Keyword(s):  
Type Material ◽  
Numerical Analyses ◽  
Herbarium Specimens ◽  
Taxonomic Studies

Delphinium ellipticovatum, D. tianshanicum and D. winklerianum (Ranunculaceae) share some important characters in leaf division, pedicel pubescence and the shape of the spur of upper sepals. They have been considered to be different mainly in the characters of bracteoles (shape, size, indumentum, and position on pedicels). Our critical observations on herbarium specimens (including type material) and living plants, together with numerical analyses of the bracteole characters within and between populations of the species in question, have demonstrated that, in addition to D. kuanii previously already synonymized with D. winklerianum, both D. ellipticovatum and D. tianshanicum are also indistinguishable from D. winklerianum. We therefore further place D. ellipticovatum and D. tianshanicum also in synonymy with D. winklerianum.

The ecology and genetics of fitness in Chlamydomonas . II. The properties of mixtures of strains

1990 ◽  
Vol 240 (1298) ◽  
pp. 323-350 ◽  
Keyword(s):  
Pure Culture ◽  
General Tendency ◽  
Average Effect ◽  
Physical Environments ◽  
Unicellular Green Alga ◽  
Excess Production ◽  
Pure Cultures ◽  
Predictor Of Success ◽  
Genotype Interaction ◽  
Series Of Experiments

Whether or not mixtures of strains possess special properties depends on whether or not their component genotypes interact with one another. This paper describes a series of experiments designed to investigate genotype-by-genotype interaction among species of the unicellular green alga Chlamydomonas when grown axenically as liquid cultures in chemically defined media. It was shown that strains varied substantially in their average effect on the overall production of mixed cultures, and that specific interactions between pairs of genotypes were also significant, though small. This conclusion was confirmed by experiments in which strains were cultured separately in growth medium that had been con­ditioned by the prior culture of another strain. However, there was no consistent general tendency for mixtures to be more productive than the average of their components in pure culture; some mixtures in some physical environments were markedly more productive than their com­ponent means, but other mixtures in other environments were markedly less productive. The average effect of a strain on the production of mixtures was uncorrelated with its performance in pure culture, showing that fitness measured in pure culture may be a poor predictor of success in mixed populations. However, the average effect of a strain in simple mixtures was correlated with its effect in more complex mixtures. Com­plex mixtures themselves displayed properties similar to, but more extreme than, those of simple mixtures; thus, in an environment where pairwise mixtures tended to outyield pure cultures, excess production tended to increase with mixture complexity. The results of these experiments seem to be consistent with those of comparable agronomic trials.

STUDIES IN THE GENUS CALICIOPSIS

1963 ◽  
Vol 41 (4) ◽  
pp. 503-543 ◽  
Author(s):  
A. Funk
Keyword(s):  
Pure Culture ◽  
Nitrogen Sources ◽  
Developmental Studies ◽  
Extensive Field ◽  
Carbon Compounds ◽  
Effects Of Ph ◽  
Pure Cultures ◽  
Dark Staining ◽  
Host Parasite ◽  
A New Species

Three species of the genus Caliciopsis, all of which produce cankers on conifers, were investigated with respect to development, morphology, general biology, and pathogenicity. Caliciopsis orientalis is described as a new species. Developmental studies have shown that the ascocarps originate from the surface of an erumpent stroma. The female sexual structures are formed from dark-staining hyphae which arise in the core of the young ascocarp. Certain of these hyphae send out trichogynes which penetrate to the outside of the ascocarp. The hyphae enlarge greatly and produce clusters of ascogonia by a budding process or through meristogenous division of the hyphal cells. The ascogonia may further divide by septum formation and thus become multicellular. Septate, branching ascogenous hyphae grow out from the ascogonia and give rise to tufts of asci from the terminal cells. The stalks of the asci elongate enormously as they are carried up into the hymenium. Homologous development and structure were shown in several members of the Caliceaceae. Differences in the final appearance of the hymenium were attributed to the absence of extensive ascogenous hyphae in the Caliceaceae, but the fundamental similarities were interpreted as evidence of a phylogenetic relationship with Caliciopsis. Comparison of the asci, hymenium, and general habit of two genera of the Coryneliaceae with Caliciopsis confirmed the opinion of previous workers that the two groups are related. Observations on fruiting cycles revealed developmental correlations which indicated the possibility of functional spermatia, but experimental spermatization failed to prove this. Data on spore dissemination, germination, and penetration were also gathered. Canker anatomy and host–parasite relationships were elucidated. Pure cultures were obtained from both spermatia and ascospores. The latter were used to determine nutritional requirements of the fungus by measuring growth response to 14 carbon compounds, 5 nitrogen sources, and 7 vitamins. The effects of pH, temperature, and aeration on vegetative growth in pure culture were also studied. Extensive field observations revealed that one species (C. pseudotsugae) is widespread in British Columbia on three native conifers, and that in addition to primary pathogenicity it offers opportunities for associative effects to other forest pathogens which may result in serious damage. Behavior in pure culture confirmed the evidence of association between the pathogens involved. Pathogenicity was proved by extensive field inoculations.

The isolation of blue-green bacteria in pure culture

1974 ◽  
Vol 20 (2) ◽  
pp. 272-273 ◽  
Author(s):  
Howard D. McCurdy Jr. ◽  
Walter Hodgson
Keyword(s):  
Pure Culture ◽  
Green Bacteria ◽  
Membrane Filters ◽  
Convenient Means ◽  
Pure Cultures

Omnimixer treatment followed by surface plating of colonies from membrane filters provides a convenient means for the isolation of pure cultures of blue-green bacteria.

Massarina walkeri n.sp., the teleomorph of Acrocalymma medicaginis from Medicago sativa contrasted with Leptosphaeria pratensis, L. weimeri n.sp., and L. viridella

1991 ◽  
Vol 69 (3) ◽  
pp. 569-573 ◽  
Author(s):  
R. A. Shoemaker ◽  
C. E. Babcock ◽  
J. A. G. Irwin
Keyword(s):  
New Species ◽  
Medicago Sativa ◽  
Pure Culture ◽  
Similar Species ◽  
A New Species

The teleomorph of Acrocalymma medicaginis Alcorn & Irwin was formed in pure culture. It is described as a new species, Massarina walkeri. It is contrasted with three somewhat similar species that parasitize legumes: Leptosphaeria pratensis Saccardo & Briard in Briard, Leptosphaeria weimeri n.sp. (anamorph Stagonospora meliloti (Lasch) Petrak), and L. viridella (Peck) Saccardo.

scholarly journals Comparison of Six Commercially Available Transport Media for Maintenance of Serpulina (Treponema) Hyodysenteriae

1992 ◽  
Vol 4 (3) ◽  
pp. 285-292 ◽  
Author(s):  
G. E. Duhamel ◽  
R. J. Bernard ◽  
M. R. Mathiesen ◽  
K. M. Eskridge
Keyword(s):  
Pure Culture ◽  
Selective Medium ◽  
Fecal Flora ◽  
Transport Medium ◽  
Selective Transport ◽  
Incubation Periods ◽  
Pure Cultures ◽  
Treponema Hyodysenteriae ◽  
Better Than ◽  
Anaerobic Media

Two anaerobic (A1 and A2), 1 selective (S1), and 3 conventional (C1, C2, and C3) transport media formulations were compared for their capacity to maintain the viability of Serpulina (Treponema) hyodysenteriae. Initial experiments compared the recovery of S. hyodysenteriae from pure cultures held in each transport medium for 0.5, 1, 2, 3, 5, and 7 days at −40 C, 4 C, 25 C, and 36 C. Subsequent experiments compared each transport medium for maintenance of S. hyodysenteriae in fecal specimens obtained from experimentally infected pigs after holding for up to 7 days at 25 C. In each experiment, the viability of S. hyodysenteriae in each transport medium incubated at each temperature and for each period was determined by inoculating the transport medium onto either trypticase soy agar with 5% sheep blood or selective BJ agar and incubating at 42 C anaerobically. Viability and fecal flora contamination were evaluated blindly after 2-, 4-, and 6-day incubation periods. At −40 C, recovery of viable S. hyodysenteriae from pure culture did not differ among the transport media from 0.5 to 7 days, and all of the transport media consistently maintained the viability of the spirochetes for 7 days. At 4 C, the anaerobic and selective transport media maintained the viability of pure cultures of S. hyodysenteriae significantly better than did the conventional transport media group at day 7 ( P = 0.019). At the same temperature, the anaerobic media maintained viability better than did the conventional media at 5 days ( P < 0.042). At 25 C, the anaerobic transport media were significantly better than the conventional transport media at maintaining the viability of pure cultures of the spirochetes at 2, 3, and 5 days ( P < 0.018) and were significantly better than the selective medium at 3 days (P = 0.012). At 36 C, the recovery of viable spirochetes was significantly better with the anaerobic transport media than with both the conventional media for days 2–7 ( P < 0.006) and the selective medium for days 3–7 ( P < 0.049). Fecal specimens held in transport media Al and C1, as a group, had significantly higher viability than those held in the other transport media formulations taken as a group at all incubation times, except 0.5 day ( P < 0.0046). Contamination of selective BJ medium by fecal flora was markedly higher after holding fecal specimens in conventional transport media than in anaerobic and selective transport media. In a dilution trial of a pure culture of spirochetes, transport media Al and A2 maintained the viability of 108 S. hyodysenteriae for 7 days; however, medium Al was 10–100-fold more effective than medium A2 when lower initial concentrations of spirochetes were sampled. In a dilution trial of a fecal specimen, medium Al maintained the viability of 101 spirochetes for 2.5 days compared with 103 with medium C1. Overall, media A1 and C1 were the most satisfactory transport media for recovery of viable S. hyodysenteriae from fecal specimens held at 25 C for up to 7 days.

scholarly journals Enhanced Removal of a Pesticides Mixture by Single Cultures and Consortia of Free and ImmobilizedStreptomycesStrains

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
María S. Fuentes ◽  
Gabriela E. Briceño ◽  
Juliana M. Saez ◽  
Claudia S. Benimeli ◽  
María C. Diez ◽  
...  
Keyword(s):  
Mixed Culture ◽  
Pure Culture ◽  
Immobilized Cells ◽  
Mixed Cultures ◽  
Ex Situ ◽  
Antagonistic Effects ◽  
Pure Cultures

Pesticides are normally used to control specific pests and to increase the productivity in crops; as a result, soils are contaminated with mixtures of pesticides. In this work, the ability ofStreptomycesstrains (either as pure or mixed cultures) to remove pentachlorophenol and chlorpyrifos was studied. The antagonism among the strains and their tolerance to the toxic mixture was evaluated. Results revealed that the strains did not have any antagonistic effects and showed tolerance against the pesticides mixture. In fact, the growth of mixed cultures was significantly higher than in pure cultures. Moreover, a pure culture (Streptomycessp. A5) and a quadruple culture had the highest pentachlorophenol removal percentages (10.6% and 10.1%, resp.), whileStreptomycessp. M7 presented the best chlorpyrifos removal (99.2%). Mixed culture of allStreptomycesspp. when assayed either as free or immobilized cells showed chlorpyrifos removal percentages of 40.17% and 71.05%, respectively, and for pentachlorophenol 5.24% and 14.72%, respectively, suggesting better removal of both pesticides by using immobilized cells. These results reveal that environments contaminated with mixtures of xenobiotics could be successfully cleaned up by using either free or immobilized cultures ofStreptomyces, throughin situorex situremediation techniques.

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