Beet yellows virus
G. E. Russell
Plant Breeding Institute, Trumpington, Cambridge, England
Watson (1942) and
Virus de la jaunisse de la betterave (Rev. appl. Mycol. 15: 548)
Beta virus 4 (Rev. appl. Mycol. 36: 308)
Corium betae (Rev. appl. Mycol. 19: 229)
A virus with flexuous filamentous particles c. 1250 nm long. Transmitted by
many species of aphid in the semi-persistent manner but by sap inoculation only with
difficulty. Host range moderate, mainly in the Chenopodiaceae. Widely distributed
throughout the beet-growing areas of the world.
Causes a yellows disease in Beta vulgaris
(sugar beet, red beet, spinach
beet, etc.) and in Spinacia oleracea
World-wide in major sugar beet growing areas.
Host Range and Symptomatology
Host range is moderate, mainly in the Chenopodiaceae; species in at least ten
dicotyledonous families have been infected experimentally
readily by aphid inoculation, with difficulty by manual inoculation of sap, for example
to the following species:
Beta vulgaris (sugar beet). Young leaves of glasshouse plants often show
vein-clearing and vein-etch
Older leaves of field and glasshouse beet
become yellow, thickened and brittle and usually have numerous small red or brown
Chenopodium foliosum or C. capitatum. Acute stunting, distortion and
vein-clearing in young leaves
and usually premature death.
Claytonia perfoliata. Plants inoculated by aphids show systemic red spots
and chlorosis in older leaves
Manually inoculated plants develop red
necrotic lesions in inoculated leaves but do not become infected systemically
Sugar beet, Claytonia perfoliata or Tetragonia expansa are suitable for
Claytonia perfoliata is a good host for sap inoculation tests and also for testing
Sugar beet and Chenopodium foliosum are satisfactory alternatives although in
these the virus may become systemic even after sap inoculation.
Many minor variants have been isolated from local lesions, producing symptoms in
sugar beet ranging from very mild yellowing to very severe vein-etch and leaf necrosis.
All are apparently serologically related and there is usually complete cross-protection
however, described some strains which do
not cross protect.
Transmission by Vectors
Transmissible by more than 22 species of aphids
(Kennedy, Day & Eastop, 1962
but Myzus persicae
and Aphis fabae
are the principal vectors in the field.
All instars transmit but adults are the most efficient. Transmission is of the
the virus being retained by the
vector for up to 3 days, with a half-life of about 8 hr. For optimum transmission,
acquisition feeds of more than 12 hr and test feeds of at least 6 hr are necessary.
Probably no latent period. Not transmitted to progeny of vectors. Vectors do not retain
virus after moulting
Transmission through Seed
Early reports of seed transmission have not been confirmed.
Transmission by Dodder
Several species can transmit
(Fuchs & Beiss, 1954
Aphids can acquire virus
from some non-transmitting species of dodder growing on infected plants
The virus is weakly immunogenic. Antisera may be prepared by intravenous,
intramuscular or intraperitoneal injections of clarified sap from infected plants; sap
from Claytonia perfoliata
is particularly suitable. Tube-precipitin or
slide-agglutination tests, using clarified sap, are satisfactory for routine diagnosis
and crude quantitative assays.
No evidence of serological relationship to any other virus
(Brandes & Bercks, 1965
apple chlorotic leaf spot
apple stem-pitting and
citrus tatter-leaf viruses
in several features, particularly particle
morphology, symptomatology and difficulty of sap inoculation
Stability in Sap
Thermal inactivation point (10 min) in sap is about 55°C; dilution end point
is up to 10-4
depending on host plant used. Infectivity is retained in
frozen sap for more than a year but rarely for more than 1 day at 20°C.
The virus is very unstable. Partial purification from clarified sap has been
achieved by differential centrifugation. The virus forms a single light-scattering
zone when centrifuged in sucrose density gradients
Properties of Particles
Flexuous filamentous particles about 1250 nm long and 10 nm in diameter with
sub-units arranged around a hollow core
(Horne, Russell & Trim, 1959
in a helix
of pitch between 3.0 and 3.4 nm
(Varma, Gibbs, Woods & Finch, 1968)
achieved by mixing 2% phosphotungstate with virus in clarified sap
Relations with Cells and Tissues
Particularly associated with degeneration of phloem tissues. Arrays of virus
particles have been found in chloroplasts
(Cronshaw, Hoefert & Esau, 1966
Beet yellows virus often occurs in beet together with
beet mild yellowing
beet western yellows viruses
which, however, are transmitted by aphids in the persistent
manner. They also differ from beet yellows virus in symptomatology, host range, particle
morphology and in serological tests
Gold & Duffus, 1967
- Bennett, Tech. Bull. U.S. Dep. Agric. 1218, 63 pp., 1960.
- Brandes & Bercks, Adv. Virus Res. 11: 1, 1965.
- Cronshaw, Hoefert & Esau, J. Cell Biol. 31: 429, 1966.
- Duffus, Phytopathology 54: 736, 1964.
- Fuchs & Beiss, Naturwissenschaften 41: 506, 1954.
- Gibbs, Adv. Virus Res. 14: 288, 1969.
- Gold & Duffus, Virology 31: 308, 1967.
- Horne, Russell & Trim, J. molec. Biol. 1: 234, 1959.
- Hull, Bull. Minist. Agric. Fish. Fd Lond. 142, 53 pp., 1950.
- Kennedy, Day & Eastop, A conspectus of aphids as vectors of plant viruses,London, Commonwealth Institute of Entomology, 1962.
- Mundry, Z. Naturf. Ser. B. 13: 19, 1958.
- Roland, Sucr. belge 55: 213, 1936.
- Russell, Nature, Lond. 197: 623, 1963.
- Russell, Ann. appl. Biol. 53: 377, 1964.
- Russell, Br. Sug. Beet Rev. 37: 77, 1968.
- Sylvester, J. Am. Soc. Sug. Beet Technol. 9: 56, 1956.
- Varma, Gibbs, Woods & Finch, J. gen. Virol. 2: 107, 1968.
- Watson, Ann. appl. Biol. 29: 358, 1942.
- Watson, Proc. R. Soc. B, 133: 200, 1946.
- Watson, Rep. 7th Commonwealth Entom. Conf. London: 157, 1960.
Photographs: courtesy of Plant Breeding Institute, Cambridge;
Rothamsted Experimental Station.
Leaves from glasshouse-grown sugar beet seedlings: (left) virus-free,
Mature leaf of field-infected sugar beet, showing chlorosis and necrotic
spots which are usually more numerous near the leaf tip. Such leaves are invariably
thickened and brittle.
Chenopodium foliosum seedlings: (left) virus-free,
(right) infected, showing vein-clearing and distortion in young leaves.
Leaves of Claytonia perfoliata: (left) virus-free, (right)
Electron micrograph of part of a filament showing periodicity along axis.
Bar represents 100 nm.