Citrus tristeza virus
W. C. Price
Guinobatan Experiment Station, Guinobatan, Albay, Phillippines
Meneghini (1946) and
Fawcett & Wallace (1946),
by Kitajima et al. (1964).
Citrus quick decline virus
(Fawcett & Wallace, 1946)
A virus with highly flexuous filamentous particles, c. 2000 x 12 nm,
restricted to the family Rutaceae. Causes a severe disease in only a few species.
Common wherever citrus is grown. Transmitted by aphids, not by sap inoculation. Aphids
retain virus up to 48 h when starved.
Tristeza, or quick decline, of commercial varieties of citrus on sour orange
root-stock; stem pitting, or stunt bush, of grapefruit; die-back of lime; seedling
yellows of sour orange; and decline of Ellendale mandarin and Pera orange.
World-wide in tropical and semi-tropical regions where citrus is grown.
Host Range and Symptomatology
Most varieties of Citrus
and a few species in certain other genera of the
family Rutaceae, such as Aeglopsis, Afraegle,
susceptible to infection. A majority are, however, tolerant of commonly occurring
strains of the virus. Tristeza is principally a disease of sweet orange or other
varieties when grown on sour orange rootstock, and of grapefruit, lime, and calamondin.
Citrus aurantifolia (West Indian lime, Key lime, Mexican lime, Galego lime,
Kagzi lime). Young leaves on infected seedlings are small, develop yellow flecks along
their veins, and become cupped or canoe-shaped; stems are pitted under the bark
(Wallace & Drake, 1951).
C. sinensis (sweet orange) plants on C. aurantium (sour orange) rootstock
suddenly wilt, decline, and die (quick decline;
Fig.1), or develop a characteristic
overgrowth at the bud-union and honeycombing in the sour orange stock just below
C. aurantifolia is perhaps the best species for maintaining cultures because it
displays diagnostic symptoms.
Many strains, differing in virulence, are found in nature. A few have been isolated
(Grant & Higgins, 1957
The following are probably the most common
naturally occurring strains of tristeza virus:
Citrus seedling yellows virus
Causes severe yellowing and
stunting of seedlings of Eureka lemon, Seville orange, grapefruit, and citron. (Some
authors regard seedling yellows virus as being distinct from tristeza virus, but
occurring with it.)
Grapefruit stem pitting virus
(Oberholzer, Mathews & Stiemie, 1949);
grapefruit stunt bush virus
In Australia, S. Africa and S.
America, infected trees are stunted and bushy; leaves are sparse, small, rounded,
and develop interveinal chlorosis; fruit is small, misshapen, and has thick rind;
wood of trunk and large limbs is pitted with longitudinal depressions; main scaffold
branches are twisted and distorted. This strain, or a similar one, is responsible
for the decline of calamondin trees in the Philippines
Lime die-back virus
(Hughes & Lister, 1949).
Causes vein flecking on
young leaves, severe pitting of wood of twigs and branches, stunting of trees, and
die-back with eventual death.
Ellendale mandarin decline virus
This strain may be the same
as, or similar to, the citrus seedling yellows strain.
Transmission by Vectors
Transmissible most efficiently by the tropical citrus aphid, Toxoptera
Costa & Grant, 1951
less efficiently by Aphis
and T. aurantii
(Dickson, Flock & Johnson, 1951
Norman & Grant, 1956
be acquired in a few seconds and transmitted in a few seconds feeding. Latent period
can retain the virus for as long as 24 h when not allowed to
feed. It has been suggested
that tristeza virus is a circulative, non-propagative virus. Recent
work (Retuerma &
Price, unpublished) suggests that it may be both stylet-borne and circulative.
Transmission through Seed
Transmission by Dodder
Reported to be transmitted by Cuscuta americana
(Knorr & Price, 1954
No antisera have been prepared.
Several authors have found that infection of test plants with mild strains of tristeza
virus protects them, at least in some cases, from more severe strains. Cross-protection
tests have given evidence for relationship of seedling yellows, stem pitting, and
Ellendale mandarin decline viruses to the tristeza virus complex
Stability in Sap
A few flexuous filaments thought to be tristeza virus particles were found in
preparations obtained by high-speed centrifugation of sap from leaves
(Kitajima et al., 1964
Bar-Joseph, Loebenstein & Cohen (1970)
found large numbers of such particles in preparations made from peeled bark of diseased
West Indian lime seedlings. The method was as follows. Grind frozen tissue with mortar
and pestle in liquid air. Thaw and extract twice with 0.05 M Tris/HCl buffer pH 7.4
(1 g/12.5 ml). Centrifuge 10 min at 4000 g
. then 5 min at 8000
. To every 100 ml of the supernatant add 4 g polyethylene glycol
(M. Wt 6000) and 4 ml 20% NaCl. Centrifuge 15 min at 16,000 g
Suspend pellets in 0.04 M phosphate buffer pH 8.2. Clarify by centrifuging 10 min at
. Sediment at 29,000 rpm in Spinco No. 30 rotor for 90 min. Suspend
in water and centrifuge 10 min at 5000 g
Properties of Particles
Sedimentation coefficient (s20,w
) determined in sucrose density
gradients: 140 ± 10 S at zero depth
(Bar-Joseph et al., 1970
Particles are very flexuous filaments c.
2µm long and 10-11 nm in
Visible in leaf dip preparations, or in large numbers in bark dip
preparations, mounted in phosphotungstate.
Relations with Cells and Tissues
Flexuous filamentous particles occur in large numbers in phloem cells
but not in other cells. Destruction of phloem tissues in sour orange rootstock is
responsible for quick decline of orchard trees.
- Anon., Agr. Gaz. N.S.W. 61: 365, 1950.
- Bar-Joseph, Loebenstein & Cohen, Phytopathology 60: 75, 1970.
- Costa & Grant, Phytopathology 41: 105, 1951.
- Dickson, Flock & Johnson, Calif. Citrogr. 36: 135, 1951.
- Fawcett & Wallace, Calif. Citrogr. 32: 50, 1946.
- Fraser, Agr. Gaz. N.S.W. 63: 125, 1952.
- Grant & Higgins, Phytopathology 47: 272, 1957.
- Hughes & Lister, Nature, Lond. 164: 880, 1949.
- Kitajima, Silva, Oliveira, Muller & Costa, Nature, Lond. 201: 1011, 1964.
- Knorr & Price, Rep. Fla agric. Exp. Stn 195, 1954.
- Meneghini, Biologico 12: 285, 1946.
- Norman & Grant, Proc. Fla St. hort. Soc. 69: 38, 1956.
- Oberholzer, Mathews & Stiemie, Sci. Bull. Dep. Agric. S. Afr. 287, 17 pp., 1949.
- Price, Virology 29: 285, 1966.
- Price, Indian Phytopath. 21: 159, 1968.
- Stubbs, J. Dep. Agric. Vict. 50: 124, 1952.
- Stubbs, Aust. J. agric. Res. 15: 752, 1964.
- Wallace & Drake, Calif Citrogr. 36: 136, 1951.
Sweet orange on sour orange rootstock in quick decline phase ot tristeza.
(Photo courtesy J. M. Wallace.)
Electron micrograph of filamentous particles in a portion of a phloem cell
of a West Indian lime seedling infected with tristeza virus.
Two filamentous particles, c. 2000 x 12 nm in an electron micrograph
of a dip preparation from a West Indian lime leaf infected with tristeza virus.
Honeycombing in the sour orange portion of a strip of bark removed from the
graft union of a tristeza-diseased pummelo tree on sour orange rootstock.
Stem pitting in the trunk of a calamondin tree infected with tristeza virus.
(Photo courtesy D. M. Nora.)