Prunus necrotic ringspot virus
R. W. Fulton
Department of Plant Pathology, University of Wisconsin, Madison, Wisconsin, USA
Described by Cochran & Hutchins (1941) and
Moore & Keitt (1944).
- Peach ringspot virus (Rev. appl. Mycol. 21: 85)
- Cherry (sour) necrotic ringspot virus
(Moore & Keitt, 1944)
- Necrotic ringspot virus
(Berkeley et al., 1951)
- Prunus ringspot virus (Rev. appl. Mycol. 39: 721)
An RNA-containing virus with isometric particles about 23 nm in diameter. Readily transmitted by
inoculation with extracts of young leaves ground in buffer, but very labile. The virus has a fairly
wide host range among dicotyledonous plants, no known insect vectors, but transmission by mites and
nematodes has been reported. It is transmitted by pollen to seed and to pollinated plants.
Causes necrotic ringspot in many species of Prunus
) (= Stecklenberg disease), often
with subsequent recovery from symptoms. It causes sweet cherry rugose mosaic, almond calico
(Nyland & Lowe, 1964
a mosaic disease of rose, and is common in hop
), in which it is symptomless
or associated with ring and band mosaic. Some strains and serotypes cause line pattern diseases of plum
(Seneviratne & Posnette, 1970
Worldwide in temperate regions.
Host Range and Symptomatology
The host range is fairly wide; naturally and experimentally, the virus has infected species in 21
Kirkpatrick, Lindner & Cheney, 1967
- Cucumis sativus (cucumber). Prominent chlorotic primary lesions, systemic tip killing followed
by extremely stunted and compact growth of axillary buds (Fig.3).
- Momordica balsamina. Necrotic primary lesions (Fig.1),
occasionally systemic necrosis.
- Cyamopsis tetragonoloba. Large, dark local lesions (Fig.2),
systemic vein necrosis.
- Prunus serrulata Shirofugen reacts to implanted virus-carrying buds with local necrosis
- Prunus persica, P. mahaleb, or Vinca rosea are suitable for maintaining cultures. As
a source of virus for purification, cucumber cotyledons 3-5 days after inoculation are suitable;
cherry petals also have been used (Tremaine & Willison, 1961).
- Momordica balsamina is a good local lesion host; Cucumis sativus has also been used.
Many isolates differ slightly in herbaceous host range or symptomatology
(Waterworth & Fulton, 1964
One common type infects Phaseolus vulgaris
and Vigna sinensis
isolates do not. The recurrent strain causes ringspot symptoms each year on cherry; others produce
symptoms only once. The Danish plum line pattern strain and the apple mosaic virus serotype cause
line pattern symptoms in plum (Fulton, 1968
Transmission by Vectors
No insect vector is known, in spite of extensive surveys
(Swenson & Milbrath, 1964
). The virus
is pollen-borne in cherry and infects trees when they are pollinated with virus-carrying pollen
(George & Davidson, 1964
reported transmission by the mite Vasates fockeui;
Fritzsche & Kegler (1968)
reported transmission by the nematode Longidorus macrosoma
Transmission through Seed
Transmitted in up to 70% of the seed of Prunus
(Megahed & Moore, 1967
in a smaller proportion of seed of peach and some other species.
Transmission by Dodder
Not transmitted by Cuscuta campestris.
The virus is moderately immunogenic. Antiserum can be produced in rabbits by intramuscular
injections of virus emulsified in Freunds incomplete adjuvant. Injections are more effective at 3-4
day intervals than at longer intervals; intravenous injections are relatively ineffective. The virus
reacts well in agar double diffusion tests and in liquid precipitin tests, in which precipitates are
Prunus necrotic ringspot virus is closely related serologically to Danish plum line pattern virus,
but not to Cations Shiro plum line pattern virus. It is distantly serologically related to rose mosaic
viruses, which also cause line pattern of plum
). It may occur with, and
somewhat resembles, prune dwarf virus
but there is no serological cross reaction between these two viruses.
Stability in Sap
In undiluted sap most infectivity is lost within a few minutes; in diluted sap maximum longevity
is 9-18 hr. Infectivity is stabilized in extracts by 0.01 M Na-diethyldithiocarbamate but not by similar
concentrations of cysteine hydrochloride or 2-mercaptoethanol
). When infectivity
is stabilized, thermal inactivation points (10 min) range from 55 to 62°C for different isolates
(Waterworth & Fulton, 1964
Virus in tissue withstands rapid freezing to -78°C, but not slow
freezing (Fulton, 1957b
The following method is effective
). Homogenize heavily infected cucumber cotyledons
cold in 1.5 ml buffer/g tissue. The buffer is 0.02 M phosphate, pH 8.0, and is 0.02 M with respect to
2-mercaptoethanol and Na-diethyldithiocarbamate. After low speed centrifugation, mix the supernatant
liquid thoroughly with 0.8 volumes of hydrated calcium phosphate and again centrifuge at low speed for
10-20 min. Sediment the virus by centrifuging 3.5 hr at 78,000 g
. Resuspend the pellets
in phosphate buffer, bring to pH 4.8-5.0 with citric acid and remove the precipitate by centrifugation.
Readjust the supernatant fluid, containing the virus, to pH 7 and concentrate the virus by high speed
centrifugation. Density gradient centrifugation
(van Regenmortel & Engelbrecht, 1963
(van Regenmortel, 1964
) or precipitation of host protein by anti-host serum
) have been used for further purification.
Properties of Particles
The virus has two kinds of particles, with sedimentation coefficients (s20, w
variously reported as 79-97 S and 107-119 S. Both particle types are reported to be
Molecular weight: 5.2-7.3 x 106.
A260/A280: c. 1.56.
Particles are isometric, 22-23 nm in diameter
). They disintegrate readily in
phosphotungstate unless fixed first in 1% glutaraldehyde.
About 16% of particle weight. Molar percentages of the nucleotides: G27; A25; C21;
U27 (Barnett & Fulton, 1969
Protein: Subunits have a molecular weight of about 2.5 x 104 and contain about
196 amino acid residues (Barnett & Fulton, 1969).
Relations with Cells and Tissues
NotesPrune dwarf virus
causes shock symptoms in sour cherry resembling those caused by prunus necrotic
ringspot virus but they are usually milder and involve only leaves that are unfolded and partially
expanded, whereas those caused by prunus necrotic ringspot virus appear in small leaves before they
- Barnett & Fulton, Virology 39: 556, 1969.
- Berkeley, Cation, Hildebrand, Keitt & Moore, U.S.D.A. Handbook 10: 164, 1951.
- Bock, Ann. appl. Biol. 57: 131, 1966.
- Bock, Ann. appl. Biol. 59: 437, 1967.
- Cochran & Hutchins, Phytopathology 31: 860, 1941.
- George & Davidson, Can. J. Pl. Sci. 44: 383, 1964.
- Fritzsche & Kegler, Tag. Ber. dt. Akad. Landw. Wiss. Berl. 97: 289, 1968.
- Fulton, Phytopathology 47: 215, 1957a.
- Fulton, Phytopathology 47: 683, 1957b.
- Fulton, Phytopathology 58: 635, 1968.
- Kirkpatrick, Lindner & Cheney, Pl. Dis. Reptr 51: 786, 1967.
- Megahed & Moore, Phytopathology 57: 821, 1967.
- Moore & Keitt, Phytopathology 34: 1009, 1944.
- Nyland & Lowe, Phytopathology 54: 1435, 1964.
- Proeseler, Phytopath. Z. 63: 1, 1968.
- Seneviratne & Posnette, Ann. appl. Biol. 65: 115, 1970.
- Swenson & Milbrath, Phytopathology 54: 399, 1964.
- Tremaine & Willison, Can. J. Bot. 39: 1387, 1961.
- van Regenmortel, Virology 23: 495, 1964.
- van Regenmortel & Engelbrecht, S. Afr. J. agric. Sci. 6: 505, 1963.
- Waterworth & Fulton, Phytopathology 54: 1155, 1964.
Local necrotic lesions in Momordica balsamina.
Local necrotic lesions in Cyamopsis tetragonoloba.
Extreme dwarfing of systemically infected Cucumis sativus. Plant has been infected
about 6 weeks.
Purified preparation of virus, fixed in glutaraldehyde and stained with phosphotungstate.
Bar represents 50 nm. (Micrograph by G. Gaard.)
Systemic necrotic ringspot symptoms in leaf of Prunus cerasus.