scholarly journals Susceptibility of ten red clover (Trifolium pratense) cultivars to six viruses after artificial inoculation

2014 ◽  
Vol 50 (No. 3) ◽  
pp. 113-118 ◽  
Author(s):  
J. Fránová ◽  
H. Jakešová

Seedlings of Trifolium pratense L. cultivars were mechanically inoculated with Czech isolates of Alfalfa mosaic virus (AMV), Clover yellow mosaic virus (ClYMV), Clover yellow vein virus (ClYVV), Red clover mottle virus (RCMV), White clover mosaic virus (WClMV), and a newly discovered member of the Cytorhabdovirus genus. WClMV infected 75.4% of clover seedlings; cv. Rezista was the most susceptible (93.3%), while cv. Fresko was the least susceptible (58.3%). RCMV infected 59.6% of plants; the most susceptible was cv. Tempus (77.6%), the least susceptible cv. Sprint (38.3%). While WClMV infected a higher number of seedlings, RCMV revealed more severe symptoms on affected plants. On the basis of ELISA and RT-PCR results, no cultivar was susceptible to mechanical inoculation with ClYMV and cytorhabdovirus. Moreover, cvs Fresko and Sprint were not susceptible to ClYVV and AMV, respectively.

Plant Disease ◽  
1997 ◽  
Vol 81 (7) ◽  
pp. 817-820 ◽  
Author(s):  
Robert T. Sherwood

Incidence of six viruses was tested in white clover from 28 rotationally grazed pastures of Pennsylvania (PA), New York (NY), and Vermont (VT). Each of 17 PA pastures was sampled fall 1994, spring 1995, fall 1995, and spring 1996, and 10 pastures were sampled fall 1996. Each of five NY and six VT pastures was sampled spring and fall 1995 and 1996. Enzyme-linked immunosorbent assays (ELISA) were conducted for red clover vein mosaic virus (RCVMV), white clover mosaic virus (WCMV), alfalfa mosaic virus (AlMV), peanut stunt virus (PSV), clover yellow mosaic virus (CYMV), and the potyvirus group (POTY). RCVMV, WCMV, AlMV, and POTY were detected in 28, 28, 27, and 25 of the 28 pastures and in 67, 32, 30, and 7% of the 3,065 samples tested, respectively. PSV occurred at low to moderate levels in 11 PA pastures. PSV was rare in NY and was not detected in VT. CYMV was never found. Incidence of each virus varied significantly among pastures. For any given virus, there was not a significant variation in incidence among sampling dates within the NY-VT samples. RCVMV, WCMV, and POTY varied among dates within PA.


1997 ◽  
Vol 77 (4) ◽  
pp. 601-605 ◽  
Author(s):  
P. H. Martin ◽  
B. E. Coulman ◽  
J. F. Peterson

Virus diseases are known to reduce the yield and persistence of stands of red clover (Trifolium pratense L.). Alfalfa mosaic virus (AMV) is one of the causes of mosaic in red clover and may also cause mottling and leaf distortion. The goals of this study were to identify genotypes resistant to AMV within commercial red clover cultivars and to determine the inheritance of this resistance. Cultivars and progenies were screened for resistance by means of mechanical inoculations. Plants showing no symptoms after three successive inoculations were assayed for the presence of the virus using ELISA (enzyme-linked immunosorbent assay). Resistant plants were detected at a frequency of just over 1% in the five cultivars screened. Crosses among and between resistant (R) and susceptible (S) plants were carried out over two successive cycles of selection. In cycle 1, R × R crosses produced a higher frequency of resistant plants (19.8%) in the progenies than R × S crosses (10.9%). S × S crosses produced no resistant progeny. For crosses of resistant plants from cycle 1 progeny, (R × R) × (R × R) produced 47.8%, (R × R) × (R × S) produced 31.4% and (R × S) × (R × S) produced 29.3% resistant cycle 2 progeny. Crosses of resistant and susceptible cycle 1 plants resulted in resistance frequencies in cycle 2 which were not significantly (P < 0.05) greater than cycle 1. When only resistant plants were selected for further crossing, the percentage of resistant plants increased from 1.3 to 47.8 over the two cycles of selection. It was concluded that resistance to AMV in red clover is under polygenic control and that it should be relatively simple to select a highly resistant population through recurrent selection. Key words: Red clover, Trifolium pratense L., virus disease, alfalfa mosaic virus, recurrent selection


1982 ◽  
Vol 98 (2) ◽  
pp. 455-460 ◽  
Author(s):  
S. W. Scott

SUMMARYThe effects of white clover mosaic virus infection on the yield of two red clover varieties grown alone and in mixtures with either perennial or hybrid ryegrasses were examined. The spread of this virus within the pure clover plots was rapid. Clover drymatter yields were reduced and these losses were greater in the grass–clover mixtures than in the pure clover plots. Reductions in yield of about 70% were recorded at the first cut in mixtures of Sabtoron and Sabrina. The response of the clover to different levels of virus infection was best described by a negative linear relationship.Yields of Sabrina hybrid ryegrass increased as the levels of virus infection in the clover increased. This compensated for the losses in yield of the legume, leaving total sward yields unaffected by the virus.


Plant Disease ◽  
2012 ◽  
Vol 96 (9) ◽  
pp. 1384-1384 ◽  
Author(s):  
R. A. C. Jones ◽  
D. Real ◽  
S. J. Vincent ◽  
B. E. Gajda ◽  
B. A. Coutts

Tedera (Bituminaria bituminosa (L.) C.H. Stirton vars albomarginata and crassiuscula) is being established as a perennial pasture legume in southwest Australia because of its drought tolerance and ability to persist well during the dry summer and autumn period. Calico (bright yellow mosaic) leaf symptoms occurred on occasional tedera plants growing in genetic evaluation plots containing spaced plants at Newdegate in 2007 and Buntine in 2010. Alfalfa mosaic virus (AlMV) infection was suspected as it often causes calico in infected plants (1,2) and infects perennial pasture legumes in local pastures (1,3). Because AlMV frequently infects Medicago sativa (alfalfa) in Australia and its seed stocks are commonly infected (1,3), M. sativa buffer rows were likely sources for spread by aphids to healthy tedera plants. When leaf samples from plants with typical calico symptoms from Newdegate (2007) and Buntine (2010) were tested by ELISA using poyclonal antisera to AlMV, Bean yellow mosaic virus (BYMV) and Cucumber mosaic virus (CMV), only AlMV was detected. When leaf samples from 864 asymptomatic spaced plants belonging to 34 tedera accessions growing at Newdegate and Mount Barker in 2010 were tested by ELISA, no AlMV, BYMV, or CMV were detected, despite presence of M. sativa buffer rows. A culture of AlMV isolate EW was maintained by serial planting of infected seed of M. polymorpha L. (burr medic) and selecting seed-infected seedlings (1,3). Ten plants each of 61 accessions from the local tedera breeding program were grown at 20°C in an insect-proof air conditioned glasshouse. They were inoculated by rubbing leaves with infective sap containing AlMV-EW or healthy sap (five plants each) using Celite abrasive. Inoculations were always done two to three times to the same plants. When both inoculated and tip leaf samples from each plant were tested by ELISA, AlMV was detected in 52 of 305 AlMV-inoculated plants belonging to 36 of 61 accessions. Inoculated leaves developed local necrotic or chlorotic spots or blotches, or symptomless infection. Systemic invasion was detected in 20 plants from 12 accessions. Koch's postulates were fulfilled in 12 plants from nine accessions (1 to 2 of 5 plants each), obvious calico symptoms developing in uninoculated leaves, and AlMV being detected in symptomatic samples by ELISA, inoculation of sap to diagnostic indicator hosts (2) and RT-PCR with AlMV CP gene primers. Direct RT-PCR products were sequenced and lodged in GenBank. When complete nucleotide CP sequences (666 nt) of two isolates from symptomatic tedera samples and two from alfalfa (Aq-JX112758, Hu-JX112759) were compared with that of AlMV-EW, those from tedera and EW were identical (JX112757) but had 99.1 to 99.2% identities to the alfalfa isolates. JX112757 had 99.4% identity with Italian tomato isolate Y09110. Systemically infected tedera foliage sometimes also developed vein clearing, mosaic, necrotic spotting, leaf deformation, leaf downcurling, or chlorosis. Later-formed leaves sometimes recovered, but plant growth was often stunted. No infection was detected in the 305 plants inoculated with healthy sap. To our knowledge, this is the first report of AlMV infecting tedera in Australia or elsewhere. References: (1) B. A. Coutts and R. A. C. Jones. Ann. Appl. Biol. 140:37, 2002. (2) E. M. J. Jaspars and L. Bos. Association of Applied Biologists, Descriptions of Plant Viruses No. 229, 1980. (3) R. A. C. Jones. Aust. J. Agric. Res. 55:757, 2004.


2010 ◽  
Vol 62 (3) ◽  
pp. 595-601 ◽  
Author(s):  
Dragana Petrovic ◽  
Maja Ignjatov ◽  
Zorica Nikolic ◽  
Milka Vujakovic ◽  
Mirjana Vasic ◽  
...  

This work describes the incidence and distribution of the most important bean viruses in Serbia: Bean common mosaic virus (BCMV), Bean common mosaic necrosis virus (BCMNV), Bean yellow mosaic virus (BYMV), Cucumber mosaic virus (CMV) and Alfalfa mosaic virus (AMV). The viral isolates were characterized serologically and biologically. BCMV was found in the largest number of plants (30.53%), followed by BCMNV (2.67%), CMV (5.34%), and AMV (3.41%), since BYMV was not determined. Mixed viral infections were found in several samples. The RT-PCR method was used to prove that the tested isolates belong to the BCMV, family Potyviridae and strains Russian and NL-3 D. Results obtained in this work will enable further studies of the genetic variability of bean virus isolates from Serbia. .


2016 ◽  
Vol 69 ◽  
pp. 320-320
Author(s):  
J.D. Fletcher ◽  
H. Ziebell

In a survey of 14 processing crops and 7 pea seed crops throughout Canterbury Cucumber mosaic virus (CMV) was the most widespread with crop incidences of up to 20 Alfalfa mosaic virus (AMV) up to 11 Pea seedborne mosaic virus (PSbMV) up to 9 Soybean dwarf virus (SDV) up to 2 Turnip yellows virus (TuYV) up to 2 and Bean yellow mosaic virus (BYMV) up to 35 Red clover vein mosaic virus (RCVMV) was detected in peas for the first time in New Zealand with incidences of up to 35 Pea necrotic yellow dwarf virus (PNYDV) Faba bean necrotic yellows virus (FBNYV) and Broad bean stain virus (BBSV) were not detected In a survey of 8 beetroot crops TuYV was detected in Auckland at 1 incidence but not in Hawkes Bay Beet mosaic virus was detected at 1 incidence in both regions Fungal leaf spotting pathogens appear a greater concern in beetroot In 12 dwarf bean processing crops throughout Canterbury virus was only detected in early sown crops AMV and RCVMV were most widespread with incidences of up to 9; CMV with up to 7 incidence; then BYMV TuYV and SDV each with 1 incidence No Bean common mosaic virus was detected


Plant Disease ◽  
2016 ◽  
Vol 100 (5) ◽  
pp. 890-895 ◽  
Author(s):  
John Fletcher ◽  
Joe Tang ◽  
Arnaud Blouin ◽  
Lisa Ward ◽  
Robin MacDiarmid ◽  
...  

Red clover vein mosaic virus (RCVMV) is an important virus of leguminous crops that can cause devastating losses. During a routine survey of legumes conducted on the South Island of New Zealand, RCVMV was found in mixed infections in clover plants with Alfalfa mosaic virus and White clover mosaic virus. The full-length sequence of the New Zealand isolate RCVMV-NZ from clover shared 96% nucleotide sequence identity with a chickpea isolate previously described from Washington (United States). Targeted surveys of pea, faba bean, and pasture crops showed that RCVMV-NZ is widespread on the South Island in New Zealand. This isolate is causing mild if any symptoms on experimental hosts and naturally infected plants.


Plant Disease ◽  
2004 ◽  
Vol 88 (2) ◽  
pp. 223-223 ◽  
Author(s):  
C. A. Baker ◽  
K. Beckham ◽  
E. Hiebert

In September 2002, several unthrifty Verbena canadensis ‘Homestead purple’ plants were received at the Division of Plant Industry in Gainesville, FL. Symptoms included very subtle yellowing and distortion or stunting of the younger leaves, symptoms that could be overlooked as a nutritional problem. Symptomatic leaves were ground in phosphate buffer and mechanically inoculated to a variety of plants that included Antirrhinum majus, Chenopodium amaranticolor, Datura stramonium, Gomphrena globosa, Pisum sativum, Trifolium pratense, T. repens, Vicia faba, and Vigna unguiculata. These hosts showed symptoms similar to those described for infection by Clover yellow mosaic virus (ClYMV) (3). In addition, the virus systemically infected Arachis hypogaea, Catharanthus roseus, C. quinoa, Nicotiana benthamiana, and healthy seed-grown Verbena × hybrida. No symptoms were seen in inoculated Zinnia elegans, N. glutinosa, N. clevelandii, Lycopersicon esculentum, Cucumis sativus, or Capsicum annuum. However, back inoculations of Cucumis sativus to C. amaranticolor gave typical local and systemic symptoms. Microscopic examination of leaf strips of infected V. faba revealed banded inclusions typical of the genus Potexvirus (1). Reverse-transcription polymerase chain reaction (RT-PCR) using degenerate primers for the genus Potexvirus (2) produced a 750-bp product that is the expected product for the genus Potexvirus. The RT-PCR product was cloned in pGem-T easy (Promega, Madison, WI) and sequenced. BLAST ( http://www.ncbi.nlm.nih.gov/ BLAST/ ) analysis of the sequence showed an 82% identity at the nucleotide level with the RNA polymerase gene of ClYMV. Leaf extracts of the original verbena, several inoculated hosts, and a known sample of ClYMV in N. benthamiana were tested in sodium dodecyl sulfate immunodiffusion (4) against antiserum to the degraded capsid protein of ClYMV. A reaction of identity was seen with infected samples but not with samples for comparable virus-free plants. To our knowledge, this is the first time this virus has been found in the eastern United States. It is not known how or if the presence of this noninsect transmitted virus in an ornamental will affect the agricultural, forage, or ornamental industries in the east or how widely distributed Verbena sp. infected with this virus may be at this time. References: (1.) R. G. Christie and J. R. Edwardson. Fla. Agric. Exp. Stn. Monogr. 9, 1994. (2.) A. Gibbs et al. J. Virol. Methods 74:67,1998 (3.) M. J. Pratt. Can. J. Bot. 39:655. 1961. (4) D. E. Purcifull and D. L. Batchelor. Fla. Agric. Ext. Stn. Bull. 788, 1977.


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