Cocksfoot streak virus
P. L. Catherall
Welsh Plant Breeding Station, Aberystwyth, Wales
- Described by Storey (1952) and Smith (1952).
- Cocksfoot mosaic virus (Rev. appl. Mycol. 37: 363)
- A virus with flexuous filamentous particles c. 752 x 13 nm infecting only
a few species of Gramineae. It is transmitted by several species of aphid in the
non-persistent manner and by inoculation of sap. Common in Britain and Europe.
Causes mild or severe streaking and decreases tillering of cocksfoot grass. The
virus is usually eliminated by inter-plant competition in grazed cocksfoot swards,
but is frequent in cocksfoot seed crops.
Widespread in Britain and Europe (Peto, 1955
; Slykhuis, 1958
; Klinkowski &
; Mühle & Schumann, 1959
Host Range and Symptomatology
Host range is restricted to a few species of Gramineae. Transmissible by
inoculation of sap, for example to the following:
- Diagnostic species
- Dactylis glomerata (cocksfoot) and other Dactylis spp. Conspicuous
longitudinal leaf streaks of dark and light green or yellow (Fig.1). Infected
plants are rarely stunted, but produce fewer vegetative tillers. They flower
earlier than healthy plants, but produce fewer fertile seeds (Catherall &
- Lolium multiflorum (Italian ryegrass) and L. perenne (perennial
ryegrass). Indistinct pale green or yellow streaks (Fig.2).
- Paspalum membranaceum and Setaria macrostachia. Very conspicuous
yellow streaks (Ohmann-Kreutzberg, 1963).
- Phalaris paradoxa and Lamarkia aurea. Yellow spots.
- Anthoxanthum aristatum, Avena strigosa, Bromus mollis, Festuca capillata,
Hordeum murinum, Lagurus ovatus and Setaria viridis. Symptomless infection.
- Propagation species
- Cocksfoot is suitable for maintaining cultures and for propagating virus for
- Assay species
- No known local lesion hosts. Cocksfoot and Paspalum membranaceum have
been used as test plants in host range studies and for testing aphids in vector
studies. Ohmann-Kreutzberg (1963) found that Paspalum membranaceum was
the more reliable because the incubation period of the virus in this species was
shorter (14 days) and less variable than in cocksfoot (30-50 days).
No variants have been distinguished.
Transmission by Vectors
Transmissible by several species of aphids including Myzus persicae,
Macrosiphum euphorbiae, Macrosiphum avenae, Metopolophium dirhodum
; Watson & Mulligan, 1960
). Virus can
be acquired in 10 sec and inoculated in less than 1 min. No latent period. Feeding
vectors cease to transmit within 1 hr after acquisition.
Transmission through Seed
Transmission by Dodder
In double diffusion tests in l% agar partially purified virus preparations form
a single band of precipitate with antisera prepared by intravenous injection.
Serological tests have failed to show any relationship between cocksfoot streak
and two viruses with particles of similar shape and size, namely
) and anthoxanthum
mosaic virus (Catherall, unpublished).
Stability in Sap
Infectivity of cocksfoot extracts in water or neutral 0.1 M phosphate buffer
is low. Transmission is greatly increased if a slightly acid (pH 5.9) phosphate
buffer is used. In extracts of cocksfoot in pH 5.9 phosphate buffer, the thermal
inactivation point (10 min) is about 55°C, dilution end-point about 3 x
, and infectivity is retained at 20°C for up to 16 days
No detailed information. Differential centrifugation (5000 g
15 min, 50,000 g
for 2 hr) has been used to prepare partially pure
preparations of the virus for use as immunogen.
Properties of Particles
Particles are flexuous filaments c.
752 x 13 nm (Brandes, 1959
Relations with Cells and Tissues
A virus with flexuous filamentous particles causing streaking of cocksfoot and
ryegrass in Germany was called cocksfoot streak virus (Schumann, 1969
) although no
serological tests or insect transmissions were made to substantiate this conclusion.
The virus was easily transmissible to many species of Gramineae, including Avena
sativa, Festuca pratensis
and Triticum aestivum,
which are immune to
cocksfoot streak virus in Britain.
McKinney (1956) described a virus, orchard grass mosaic, causing streaking of
cocksfoot in USA. Its vector and serological relationship with cocksfoot streak
virus are not known, but unlike cocksfoot streak it infects Avena sativa,
causing blue-green dwarfing.
Several viruses that differ serologically from cocksfoot streak virus can cause
streaking of cocksfoot. Ryegrass mosaic virus (Mulligan, 1960) is the most
difficult to distinguish from cocksfoot streak. It is easily transmissible by
inoculation of sap to many varieties of cocksfoot, but whether it occurs naturally
in cocksfoot has not been established with certainty. It has flexuous filamentous
particles c. 703 x 19 nm (Brandes, 1964), but is transmitted by eriophyid
mites and not by aphids, and is transmissible to Avena sativa and
Festuca pratensis. Cocksfoot mottle (Serjeant, 1964) and cocksfoot mild
mosaic viruses (Huth, 1968) sometimes occur in combination with cocksfoot streak
virus, but both have isometric particles c. 25-30 nm in diameter. Cocksfoot
mottle virus is transmissible by beetles to Triticum aestivum and
cocksfoot mild mosaic virus by aphids to Setaria italica (immune to
cocksfoot streak virus). Two other isometric viruses, brome mosaic (McKinney,
l944), which occurs in North America, and the related ryegrass streak (Proll
& Richter, 1965), which occurs in Europe, infect cocksfoot rarely. Both
cause local lesions in Datura stramonium and there is an unconfirmed
report that ryegrass streak virus is transmitted by nematodes.
- Brandes, Phytopath. Z. 35: 205, 1959.
- Brandes, Mitt. biol. BundAnst. Ld- u. Forstw. 110, 130 pp., 1964.
- Catherall & Griffiths, Ann. appl. Biol. 57: 141, 1966.
- Huth, Phytopath. Z. 62: 300, 1968.
- Klinkowski & Kreutzberg, Phytopath. Z. 32: 1, 1958.
- McKinney, Phytopathology 34: 993, 1944.
- McKinney, Pl. Dis. Reptr 40: 524, 1956.
- Mühle & Schumann, Phytopath. Z. 36: 314, 1959.
- Mulligan, Ann. appl. Biol. 48: 575, 1960.
- Ohmann-Kreutzberg, Phytopath. Z. 47: 113, 1963.
- Peto, J. Br. Grassld. Soc. 10:193, 1955.
- Proll & Richter, Naturwissenschaften 52: 145, 1965.
- Schumann, Arch. PflSchutz 5: 318, 1969.
- Serjeant, Pl. Path. 13: 23, 1964.
- Slykhuis, Pl. Prot. Bull. FAO. 6: 129, 1958.
- Smith, Pl. Path. 1: 118, 1952.
- Storey, Pl. Path. 1: 101, 1952.
- Watson & Mulligan, Rep. Rothamsted exp. Stn, 1959: 101, 1960.
Leaves of Dactylis glomerata, (below) healthy, others
Leaves of Lolium multiflorum, (below) healthy, (above)
Virus particles in phosphotungstate. Bar represents 100 nm (courtesy of
Rothamsted Experimental Station).