Development of annual ryegrass toxicity

1983 ◽  
Vol 34 (6) ◽  
pp. 653 ◽  
Author(s):  
BA Stynes ◽  
AF Bird
Keyword(s):  
Electron Microscope ◽  
Plant Growth ◽  
Western Australia ◽  
Growth Stage ◽  
Maximum Level ◽  
Annual Ryegrass ◽  
Physiological Aging ◽  
Bacterial Inhibition ◽  
Annual Ryegrass Toxicity ◽  
Experimental Plots

Ryegrass pasture, containing seed galls induced by Anguina agrostis and colonized by Corynebacterium rathayi, was harvested from experimental plots near Katanning in Western Australia. Plant growth stage, numbers of emerged inflorescences and numbers of galls present were estimated for 10 harvests collected at weekly intervals, commencing 22 September when the first inflorescences had emerged. The concentration of toxin (corynetoxins) at each harvest was estimated using a bacterial inhibition bioassay. Levels of toxin were up to 459 �g per m2 pasture prior to and during anthesis, but the concentration increased rapidly during the final four harvests (corresponding to ripening) and reached a maximum level of 6292 �g m-2. A possible relationship between toxicity and the presence of ultramicroscopic particles observed in the galls was investigated. Galls from each harvest were sectioned and examined under the electron microscope. Particles were not found in galls sampled prior to anthesis, but were found in galls from the last four harvests. From these results, the production of toxin appears to be related to physiological aging of the plant and may also be related to the accumulation of particles.

Dilophospora alopecuri and decline in annual ryegrass toxicity in Western Australia

1994 ◽  
Vol 45 (4) ◽  
pp. 841 ◽  
Author(s):  
IT Riley
Keyword(s):  
Western Australia ◽  
Soil Samples ◽  
Annual Ryegrass ◽  
Biological Factors ◽  
The South ◽  
Population Densities ◽  
Important Contributor ◽  
Annual Ryegrass Toxicity

Biological factors contributing to the decline in the incidence of annual ryegrass toxicity (ARGT) in Western Australia were investigated. Annual ryegrass and soil samples were collected in the area where ARGT outbreaks first occurred in Western Australia, an area where the incidence of ARGT has markedly declined. The nematode vector, Anguina funesta, was found in 68% of samples, whereas the toxigenic bacterium, Clavibacter toxicus, was detected in fewer than 2% of samples. The population densities of the nematode were low, but other attributes assayed were normal. The fungus, Dilophospora alopecuri, also associated with A. funesta, was found at 58% of the sampling sites. The abundance of D. alopecuri suggests that it is an important contributor to decline in ARGT. Therefore, the distribution of D. alopecuri in Western Australia was determined in the following season. D. alopecuri was common in the southerly range of A. funesta, but absent in the northerly range where ARGT outbreaks are still common. In the south, D. alopecuri appears to have displaced C. toxicus and reduced A. funesta populations. The findings suggest that there is potential to use D. alopecuri to control ARGT

Toxic tunicaminyluracil antibiotics identified in water-damaged wheat responsible for the death of pigs

1988 ◽  
Vol 39 (2) ◽  
pp. 245 ◽  
Author(s):  
PA Cockrum ◽  
CCJ Culvenor ◽  
JA Edgar ◽  
MV Jago ◽  
AL Payne ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Catalytic Hydrogenation ◽  
Fast Atom Bombardment ◽  
Specific Inhibition ◽  
Chemical Identification ◽  
Annual Ryegrass ◽  
Fatal Intoxication ◽  
Bacterial Inhibition ◽  
Stored Wheat ◽  
Annual Ryegrass Toxicity

A unique mixture of toxic tunicaininyluracil antibiotics, closely related to the corynetoxins which causc annual ryegrass toxicity and to the tunicamycins, has been identified in rain-damaged, stored wheat implicated in a fatal intoxication of pigs. The toxins, present at a level of approximately 4.5 mg per kg, were isolated by preparative t.1.c. They displayed specific inhibition of uridine diphospho-N-acetylglucosamine : dolichol-phosphate N-acetylglucosamine-1-phosphate transferase and bacterial inhibition consistent with this type of antibiotic, and produced symptoms in rats identical with those associated with the tunicamycin and corynetoxin complexes. Chemical identification, based on t.l.c., h.p.l.c., co-chromatography with authentic toxins and catalytic hydrogenation, was confirmed by fast atom bombardment mass spectrometry. The origin of these toxins is unknown, but the unique mixture of components detected suggests a previously unreported tunicaminyluracil antibiotic-producing microbial source.

Corynetoxins are not detoxicated by in vitro fermentation in ovine rumen fluid

1986 ◽  
Vol 37 (5) ◽  
pp. 523 ◽  
Author(s):  
P Vogel ◽  
MG McGrath
Keyword(s):  
Rumen Fluid ◽  
Annual Ryegrass ◽  
Inhibition Assay ◽  
Lolium Rigidum ◽  
In Vitro Fermentation ◽  
Bacterial Inhibition ◽  
Annual Ryegrass Toxicity

Tunicamycin and seed galls of annual ryegrass (Lolium rigidum) containing corynetoxins, the causal agents of annual ryegrass toxicity, were incubated in ovine rumen fluid-buffer mixtures. A bacterial inhibition assay of extracted incubation mixtures revealed that no detoxication occurred under these in vitro conditions.

Purification of corynetoxins from galls of annual ryegrass infected with Corynebacterium rathayi

1984 ◽  
Vol 24 (127) ◽  
pp. 617 ◽  
Author(s):  
P Vogel ◽  
H Golding ◽  
A McWilliam ◽  
J Carlin
Keyword(s):  
Column Chromatography ◽  
Purification Procedure ◽  
Annual Ryegrass ◽  
Inhibition Assay ◽  
Bacterial Inhibition ◽  
Short Column ◽  
Crude Extracts ◽  
Annual Ryegrass Toxicity

An improved, rapid and efficient purification procedure of corynetoxins, the causal agents of annual ryegrass toxicity, is described. The method relies upon bacterial gall concentration from crude seedhead material and the use of Sep Pak 'Florisil' cartridges and 'short column' chromatography to purify corynetoxinsfrom crude extracts. Extracts were monitored for toxicity using a recently developed bacterial inhibition assay.

Reliability of paddock sampling for the organisms (Anguina funesta and Clavibacter toxicus) responsible for annual ryegrass toxicity

1993 ◽  
Vol 33 (7) ◽  
pp. 861 ◽  
Author(s):  
IT Riley ◽  
JM Stanton ◽  
AGP Brown
Keyword(s):  
Western Australia ◽  
Recent History ◽  
Annual Ryegrass ◽  
Population Densities ◽  
Testing Service ◽  
Reliable Tool ◽  
History Of ◽  
Annual Ryegrass Toxicity

An examination of within-paddock distribution of the nematode (Anguina funesta) and bacterium (Clavibacter toxicus) responsible for annual ryegrass toxicity (ARGT) was undertaken to determine the reliability of farmer-collected samples in determining the risk of ARGT. Areas in Western Australia with a recent history of ARGT outbreaks were selected for study. The results indicate that the distribution of ARGT organisms is patchy in paddocks with low population densities, but as the populations grow they spread throughout the paddock. Populations are not likely to reach toxic levels before they become widespread in the paddock. Farmer-collected samples processed by the ARGT Testing Service procedure were found to be a reliable tool for the management of ARGT in Western Australia.

The distribution and importance of annual ryegrass toxicity in Western Australia and its occurrence in relation to cropping rotations and cultural practices

1980 ◽  
Vol 31 (3) ◽  
pp. 557 ◽  
Author(s):  
BA Stynes ◽  
JL Wise
Keyword(s):  
Western Australia ◽  
Cultural Practices ◽  
Annual Ryegrass ◽  
Four Seasons ◽  
Annual Ryegrass Toxicity

Surveys in Western Australia showed annual ryegrass toxicity to occur on 152 farms in an area around Gnowangerup measuring c. 100 km by 150 km and on 18 farms in four other isolated areas. The disease has spread rapidly during the last 10 years, and has been favoured by practices aimed at pasture improvement in alternating crop-pasture rotations. In the last four seasons, between 76 and 95 % of all stock mortalities due to ryegrass toxicity occurred on fields grazed in the season following a cropping year. Under these conditions, ryegrass is dominant in the pasture, and infection levels are highest. Burning these fields in autumn reduces the level of infection and makes the pasture relatively safe to graze in this season.

Soybean Phosphorus and Potassium Deficiency Detection as Influenced by Plant Growth Stage

1988 ◽  
Vol 80 (4) ◽  
pp. 586-591 ◽  
Author(s):  
W. B. Hallmark ◽  
C. J. DeMooy ◽  
H. F. Mooris ◽  
John Pesek ◽  
K. P. Shao ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Stage ◽  
Potassium Deficiency ◽  
Phosphorus And Potassium

The Preparation of Carbon Microspheres Loading Silver Antimicrobial Agent and the Study of its Properties

2012 ◽  
Vol 550-553 ◽  
pp. 1026-1029
Author(s):  
Jian Xi Ren ◽  
Jing Ya Li ◽  
Zhi Feng Cai ◽  
Jin Ming Dai ◽  
Mei Niu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Electron Microscope ◽  
Antibacterial Agent ◽  
Chemical Adsorption ◽  
Carbon Microspheres ◽  
Bacterial Inhibition ◽  
Good Antibacterial Activity ◽  
Scanning Electron

Carbon microspheres (CMSs) were used as the carrier to prepare the Ag-loading CMSs (Ag/CMSs) antibacterial agent through the method of chemical adsorption. The morphologies and structures of modified CMSs were characterized by using the field emission Scanning Electron Microscope (SEM). The results showed that silver was absorbed on the surface of CMSs. The bacterial inhibition ring experiment showed that Ag/CMSs had good antibacterial activity against Staphylococcus aureus and Escherichia coli, meanwhile the diameters of the bacterial inhibition rings were 19 mm against Staphylococcus aureus and 21 mm against Escherichia coli, respectively.

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