National survey of viruses in pastures of subterranean clover. I. Incidence of four viruses assessed by ELISA

1993 ◽  
Vol 44 (8) ◽  
pp. 1837 ◽  
Author(s):  
K Helms ◽  
WJ Muller ◽  
PM Waterhouse
Keyword(s):  
Time Course ◽  
Alfalfa Mosaic Virus ◽  
South Australia ◽  
Subterranean Clover ◽  
Nationwide Survey ◽  
Multiple Infections ◽  
Virus Infections ◽  
South Wales ◽  
Increasing Trend ◽  
Leaf Virus

A nationwide survey was made of the time-course incidence of alfalfa mosaic virus (AMV), clover yellow vein virus (CYVV), subterranean clover mottle virus (SCMoV) and subterranean clover red leaf virus (SCRLV) in improved pastures in southern regions of Australia over a 3-year period. Up to 2 500 samples (cvv. Mt Barker or Woogenellup) were collected in winter and spring of 1984, 1985 and 1986 in each of New South Wales, Victoria, South Australia. Western Australia and Tasmania, and assayed by ELISA. Usually, each sample consisted of one or two plants or parts thereof. However, a small number of samples in winter contained parts of up to 10 seedlings. For this reason, incidences are expressed as percentage of infected samples rather than percentages of infected plants. All four viruses occurred in all five states. Averaged over all states, the incidence of infected samples increased progressively from 15.3 to 19.9 to 22.5% from 1984 to 1985 to 1986, respectively, in spring, and from 6.8 to 13.8 to 18.8% respectively in winter. The incidence of samples infected with multiple infections (2-4 viruses) increased from 1.9 to 3.2 to 5.0% from 1984 to 1985 to 1986, respectively, in spring, and from 0.5 to 1.6 to 4.0%, respectively, in winter. Since 1-4 viruses were detected in each infected sample, more individual infections than infected samples were recorded. For example, the incidence of virus infections per paddock increased progressively from 17.5 to 24.1 to 28.6% from 1984 to 1985 to 1986, respectively, in spring. On a state basis, the incidence of infected samples was greatest in W.A., reaching 38.9 and 34.9% in spring of 1985 and 1986, respectively, and in S.A. reaching 30.3% in spring of 1986; these high levels were due largely to SCMoV which reached 97% in one paddock in each of the two states. In N.S.W., Vic. and Tas., the highest incidences of infected samples in either winter or spring were 21.4, 16.2 and 23.1%, respectively. Averaged over all states, the highest mean incidence recorded for samples infected with individual viruses in either winter or spring was 9.4% for AMV, 5.7% for CYW, 10.9% for SCMoV and 7.5% for SCRLV. For AMV and SCRLV, there was an increasing trend from spring 1984 to spring 1986. A similar increasing trend for SCMoV was more evident in winter than in spring. For CYVV, no time-course pattern was evident. These results support the proposition that viruses contribute significantly to 'clover-decline', a well-known problem in pastures of subterranean clover.

National survey of viruses in pastures of subterranean clover. III. Equipment for large scale screening of viruses by ELISA

1993 ◽  
Vol 44 (8) ◽  
pp. 1883 ◽  
Author(s):  
LB Hulse ◽  
K Helms ◽  
PM Waterhouse
Keyword(s):  
Immunosorbent Assay ◽  
Large Scale ◽  
New South ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Nationwide Survey ◽  
Enzyme Linked Immunosorbent Assay ◽  
South Wales ◽  
Large Scale Screening

Equipment for large scale enzyme-linked immunosorbent assay (ELISA) was developed for a 3 year nationwide survey of the incidence of four viruses in pastures of Trifolium subterraneum (subterranean clover) in New South Wales, Victoria, South Australia, Western Australia and Tasmania. Instruments were designed to (a) automate quantitatively the addition of buffer to plant samples passing through a sap extractor, (b) standardize the washing of plates in the various stages of the ELISA protocol, and (c) replace hand pipetting with a pneumatic foot-operated pipette.

THESIS SUMMARY STUDIES OF ALFALFA MOSAIC VIRUS AND SUBTERRANEAN CLOVER RED LEAF VIRUS

1979 ◽  
pp. 163-164
Author(s):  
P.B. Teh
Keyword(s):  
Mosaic Virus ◽  
Alfalfa Mosaic Virus ◽  
Subterranean Clover ◽  
Test Plant ◽  
Transmission Frequency ◽  
Virus Source ◽  
Leaf Virus

AMV was shown to be transmitted by sap, aphids and through lucerne seed, but not by Cuscuta. Virus source and test plant influenced transmission frequency. Sap-inoculation tests showed that 20 species of plants were susceptible to this virus. Thirteen species of plants from the fields where AMV had been detected were tested but only three were found to be infected with the virus.

National survey of viruses in pastures of subterranean clover. II. Statistical methodology for large scale quantitative ELISA

1993 ◽  
Vol 44 (8) ◽  
pp. 1863
Author(s):  
WJ Muller ◽  
K Helms ◽  
PM Waterhouse
Keyword(s):  
Large Scale ◽  
Time Course ◽  
Alfalfa Mosaic Virus ◽  
Subterranean Clover ◽  
Plant Sample ◽  
Statistical Methodology ◽  
Plate Design ◽  
Field Samples ◽  
Healthy Control ◽  
Sole Criterion

Statistical methodology was applied to a survey of time-course incidence of four viruses (alfalfa mosaic virus, clover yellow vein virus, subterranean clover mottle virus and subterranean clover red leaf virus) in improved pastures in southern regions of Australia, with samplings in each winter and spring over 3 years. The 100 samples per paddock collected at each time of sampling provided detection probabilities of 0.63 and 0.87 for 1% and 2% infection respectively. A microtitre plate design for ELISA was developed to include 60 field samples, 10 glasshouse-grown healthy control samples and 6 glasshouse-grown samples infected with the virus under examination. This design was used on 816 plates for each of the four viruses tested. The method used for identification of virus in sap of a plant sample from a particular paddock was that the ELISA reading was both significantly greater than healthy control readings, and an outlier in the distribution of readings of all sap samples from that paddock. It is argued that as the identification of uninfected samples as infected was highly unlikely, this double criterion method was superior to the use of each criterion separately. Use of significance above healthy control values as the sole criterion would have increased virus incidences by about 60%; use of outlier identification as the sole criterion would have increased virus incidences by about 30%. A generalized linear model with binomial errors and logit link was used for adjusting the virus incidences reported in the previous paper (Helms et al. 1993) for biases due to paddocks and/or districts not sampled on some occasions. This adjustment slightly increased overall incidences in all but one sampling and confirmed the time-course increase in incidence over the 3 years of the survey. The same model also proved to be the most appropriate for investigating the effects of year, season and district on virus incidence.

Occurrence of Phytophthora clandestina in Trifolium subterraneum paddocks in Australia

2001 ◽  
Vol 41 (2) ◽  
pp. 187 ◽  
Author(s):  
R. Aldaoud ◽  
W. Guppy ◽  
L. Callinan ◽  
S. F. Flett ◽  
K. A. Wratten ◽  
...  
Keyword(s):  
Western Australia ◽  
Root Rot ◽  
New South ◽  
New South Wales ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Soil Samples ◽  
South Wales ◽  
Differential Cultivars

In 1995–96, a survey of soil samples from subterranean clover (Trifolium subterraneum L.) paddocks was conducted across Victoria, South Australia, New South Wales and Western Australia, to determine the distribution and the prevalence of races of Phytophthora clandestina (as determined by the development of root rot on differential cultivars), and the association of its occurrence with paddock variables. In all states, there was a weak but significant association between P. clandestina detected in soil samples and subsequent root rot susceptibility of differential cultivars grown in these soil samples. Phytophthora clandestina was found in 38% of the sampled sites, with a significantly lower prevalence in South Australia (27%). There were significant positive associations between P. clandestina detection and increased soil salinity (Western Australia), early growth stages of subterranean clover (Victoria), mature subterranean clover (South Australia), recently sown subterranean clover (South Australia), paddocks with higher subterranean clover content (Victoria), where herbicides were not applied (South Australia), irrigation (New South Wales and Victoria), cattle grazing (South Australia and Victoria), early sampling dates (Victoria and New South Wales), sampling shortly after the autumn break or first irrigation (Victoria), shorter soil storage time (Victoria) and farmer’s perception of root rot being present (Victoria and New South Wales). Only 29% of P. clandestina isolates could be classified under the 5 known races. Some of the unknown races were virulent on cv. Seaton Park LF (most resistant) and others were avirulent on cv. Woogenellup (most susceptible). Race 1 was significantly less prevalent in South Australia than Victoria and race 0 was significantly less prevalent in New South Wales than in South Australia and Western Australia. This study revealed extremely wide variation in the virulence of P. clandestina. The potential importance of the results on programs to breed for resistance to root rot are discussed. in South Australia.

Izmir subterranean clover (Trifolium subterraneum L. var. subterraneum)

2007 ◽  
Vol 47 (2) ◽  
pp. 226 ◽  
Author(s):  
P. G. H. Nichols ◽  
G. A. Sandral ◽  
B. S. Dear ◽  
C. T. de Koning ◽  
D. L. Lloyd ◽  
...  
Keyword(s):  
Seed Production ◽  
Seed Set ◽  
New South ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Good Seed ◽  
Improvement Program ◽  
South Wales ◽  
Pasture Legume

Izmir is a hardseeded, early flowering, subterranean clover of var. subterraneum (Katz. et Morley) Zohary and Heller collected from Turkey and developed by the collaborating organisations of the National Annual Pasture Legume Improvement Program. It is a more hardseeded replacement for Nungarin and best suited to well-drained, moderately acidic soils in areas with a growing season of less than 4.5 months. Izmir seed production and regeneration densities in 3-year pasture phases were similar to Nungarin in 21 trials across southern Australia, but markedly greater in years following a crop or no seed set. Over all measurements, Izmir produced 10% more winter herbage and 7% more spring herbage than Nungarin. Its greater hardseededness and good seed production, makes it better suited to cropping rotations than Nungarin. Softening of Izmir hard seeds occurs later in the summer–autumn period than Nungarin, giving it slightly greater protection from seed losses following false breaks to the season. Izmir is recommended for sowing in Western Australia, New South Wales, Victoria, South Australia and Queensland. Izmir has been granted Plant Breeders Rights in Australia.

Controlling redlegged earth mite, Halotydeus destructor (Acari: Penthaleidae), with a spring spray in legume pastures

2015 ◽  
Vol 66 (9) ◽  
pp. 938 ◽  
Author(s):  
T. J. Ridsdill-Smith ◽  
C. C. Pavri
Keyword(s):  
Seed Yield ◽  
South Australia ◽  
Subterranean Clover ◽  
Early Summer ◽  
Eastern Region ◽  
The West ◽  
Halotydeus Destructor ◽  
South Wales ◽  
Redlegged Earth Mite ◽  
Clover Seed

The use of a TIMERITE® spring spray to control redlegged earth mite (RLEM), Halotydeus destructor (Tucker) (Acari: Penthaleidae), in annual pastures was evaluated on farms across Australia. RLEM populations in autumn in the treatments sprayed in spring 1998 and 1999 were 97% lower in 1999 and 97% in 2000 in the western region (Western Australia), and 93% lower in 1999 and 93% in 2000 in the eastern region (Victoria, New South Wales and South Australia). At sites in the west, control of RLEM resulted in significant increases in subterranean clover seed yield in 1999 and in clover seedling numbers in autumn 1999 and 2000. Penthaleus major (blue oat mite) populations in autumn were 60% lower in sprayed treatments, but Sminthurus viridis (lucerne flea) populations were not affected. Differences in weather between the west (where there is a hot, dry summer) and the east (where temperature and rainfall regimes are more variable in spring and early summer) seem to cause greater RLEM control and greater benefits in subterranean clover seed yield and seedling numbers with a spring spray in the west.

Alfalfa mosaic virus. [Distribution map].

2002 ◽  
Author(s):  
Keyword(s):  
New York ◽  
South Carolina ◽  
Mosaic Virus ◽  
Prince Edward Island ◽  
Alfalfa Mosaic Virus ◽  
South Australia ◽  
Distribution Map ◽  
Central Russia ◽  
South Wales ◽  
Wide Range

Abstract A new distribution map is provided for Alfalfa mosaic virus Viruses: Bromoviridae: Alfamovirus Attacks a very wide range of hosts. Information is given on the geographical distribution in EUROPE, Austria, Belarus, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Lithuania, Netherlands, Poland, Portugal, Romania, Central Russia Russia, Southern Russia, Slovakia, Slovenia, Spain, Switzerland, UK, Ukraine, Yugoslavia (Fed. Rep.), ASIA, Bangladesh, China, Nei, Menggu, Shaanxi, Zhejiang, India, Maharashtra, Iran, Iraq, Israel, Japan, Hokkaido, Honshu, Jordan, Korea Republic, Kyrgyzstan, Lebanon, Myanmar, Nepal, Pakistan, Saudi Arabia, Syria, Taiwan, Tajikistan, Turkey, Uzbekistan, Yemen, AFRICA, Algeria, Egypt, Ethiopia, Kenya, Libya, Morocco, South Africa, Sudan, Tanzania, Tunisia, Zambia, NORTH AMERICA, Canada, Alberta, British Columbia, Manitoba, New Brunswick, Ontario, Prince Edward Island, Quebec, Mexico, USA, Alabama, Arkansas, California, Connecticut, Delaware, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, Wyoming, SOUTH AMERICA, Argentina, Brazil, Parana, Chile, Colombia, Peru, Venezuela, OCEANIA, Australia, New South Wales, Queensland, South Australia, Tasmania, Victoria, Western Australia, New Zealand.

Bean leafroll virus is widespread in subterranean clover (Trifolium subterraneum L.) seed crops and can be persistently transmitted by bluegreen aphid (Acyrthosiphon kondoi Shinji)

2012 ◽  
Vol 63 (9) ◽  
pp. 902 ◽  
Author(s):  
D. M. Peck ◽  
N. Habili ◽  
R. M. Nair ◽  
J. W. Randles ◽  
C. T. de Koning ◽  
...  
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Seed Production ◽  
Alfalfa Mosaic Virus ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Bean Leafroll Virus ◽  
Leafroll Virus ◽  
Clover Seed

In the mid 2000s subterranean clover (Trifolium subterraneum) seed producers in South Australia reported symptoms of a red-leaf disease in fields with reduced seed yields. The red-leaf symptoms resembled those caused by several clover-infecting viruses. A set of molecular diagnostic tools were developed for the following viruses which are known to infect subterranean clover: Alfalfa mosaic virus; Bean leafroll virus (BLRV); Beet western yellows virus; Bean yellow mosaic virus; Cucumber mosaic virus; Pea seed-borne mosaic virus; Soybean dwarf virus and Subterranean clover stunt virus. Surveys of subterranean clover seed production fields in 2008 in the south-east of South Australia and western Victoria identified Bean leafroll virus, Alfalfa mosaic virus and Cucumber mosaic virus as present, with BLRV the most widespread. Surveys of pasture seed production fields and pasture evaluation trials in 2009 confirmed that BLRV was widespread. This result will allow seed producers to determine whether control measures directed against BLRV will overcome their seed losses. Bluegreen aphid (Acyrthosiphon kondoi) was implicated as a potential vector of BLRV because it was observed to be colonising lucerne plants adjacent to subterranean clover seed production paddocks with BLRV, and in a glasshouse trial it transmitted BLRV from an infected lucerne plant to subterranean clover in a persistent manner.

Napier subterranean clover (Trifolium subterraneum L. var. yanninicum)

2006 ◽  
Vol 46 (8) ◽  
pp. 1109 ◽  
Author(s):  
P. G. H. Nichols ◽  
M. J. Barbetti ◽  
P. M. Evans ◽  
A. D. Craig ◽  
G. A. Sandral ◽  
...  
Keyword(s):  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Improvement Program ◽  
Phytophthora Root Rot ◽  
Growing Season Length ◽  
Permanent Pasture ◽  
South Wales ◽  
Vigorous Growth ◽  
Water Holding

Napier is a late flowering F6-derived crossbred subterranean clover of var. yanninicum [(Katz. et Morley) Zohary and Heller] developed by the collaborating organisations of the National Annual Pasture Legume Improvement Program. It is a replacement for both Larisa and Meteora and has been selected for release on the basis of its greater herbage and seed production and disease resistance to both known races of clover scorch and 2 of the common races of Phytophthora root rot. Napier is recommended for sowing in Victoria, Western Australia, New South Wales, and South Australia. It is best suited to moderately acidic soils prone to water-logging and to loamy and clay soils with good water-holding capacity in areas with a minimum growing season length of 7.5 months, which extends into late November. Napier is well adapted to the permanent pasture systems found in the areas in which it will be grown. Its upright, vigorous growth makes it well suited to grazing by cattle or sheep and to fodder conservation. Napier has been granted Plant Breeders Rights in Australia.

scholarly journals Urana subterranean clover (Trifolium subterraneum L. var. subterraneum)

2006 ◽  
Vol 46 (8) ◽  
pp. 1105 ◽  
Author(s):  
P. G. H. Nichols ◽  
M. J. Barbetti ◽  
G. A. Sandral ◽  
B. S. Dear ◽  
C. T. de Koning ◽  
...  
Keyword(s):  
New South ◽  
South Australia ◽  
Field Performance ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Crop Rotations ◽  
Improvement Program ◽  
South Wales ◽  
Pasture Legume

Urana is a hardseeded, moderately early flowering F5-derived crossbred subterranean clover of var. subterraneum [(Katz. et Morley) Zohary and Heller] developed by the collaborating organisations of the National Annual Pasture Legume Improvement Program. It has been selected for release as a new cultivar on the basis of its high winter and spring herbage production and overall field performance relative to other subterranean clovers of similar maturity. Urana is recommended for sowing in Western Australia, New South Wales, Victoria, South Australia and Queensland. It is best suited to well-drained, moderately acidic soils in areas with a growing season of 5–7 months, which extends into mid-October. Urana is suited to phase farming and crop rotations. It has been granted Plant Breeders Rights in Australia.

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