Tomato yellow leaf curl virus

Tomato yellow leaf curl virus (TYLCV) can infect over 30 different kinds of plants, but it's mainly known to cause devastating losses of up to 100 per cent in the yield of tomatoes. Both field and glasshouse grown tomatoes are susceptible. TYLCV is vectored by silverleaf white fly (Bemisia tabaci). Following recent detections, silverleaf whitefly is now considered established in Victoria.

TYLCV is a begomovirus, implying it has a wide host range on dicotyledons. There are two strains of TYLCV, a mild strain and a severe strain. The mild strain was considered responsible for the recent detection of TYLCV in tomato and weed plants in northern Victoria (David Lovelace pers.com). The severe strain infects bean and tomato.

Symptoms of TYLCV

The most obvious symptoms in tomato plants are small leaves that become yellow between the veins. The leaves also curl upwards and towards the middle of the leaf (Figure 1).

Tomato plant with small, deformed and yellowing leaves

In seedlings, the shoots become shortened and give the young plants a bushy appearance. While in mature plants only new growth produced after infection is reduced in size. Although tomato production is reduced by the infection, the fruit appears unaffected.

Spread of TYLCV

TYLCV is transmitted from diseased to healthy plants by silverleaf whitefly (Bemisia tabaci), which feeds on a wide range of hosts (Figure 2). Levels of TYLCV can be correlated to the population size of its vector silverleaf whitefly. It is not known if native whiteflies can spread the virus.

The virus is not known to be seedborne or to be transmitted mechanically.

Yellow flying insect with white wings

Hosts of TYLCV

TYLCV mainly infects tomatoes but has also been reported on glasshouse grown Capsicums. Bean (Phaseolus vulgaris) (Figure 3) petunia (Petunia x hybrida) and lisanthus (Eustoma grandiflorum) show severe symptoms.

Weeds such as Datura stramonium (thorn apples) can show symptoms, others such as Malva parviflora (Marsh mellow) are symptomless carriers, while cotton and aubergine, are immune to the virus.

List of common hosts of TYLCV (Walker 2006)

  • Boerhavia erecta (erect tar vine or erect spider vine)
  • Capsicum annuum (capsicum or chilli pepper)
  • Capsicum chinense Cleome viscose (tick weed)
  • Croton lobatus (lobed croton)
  • Cyanchum acutum (common name unknown)
  • Datura stramonium (common thorn apple)
  • Euphorbia spp.
  • Eustoma grandiflora (lisianthus)
  • Lycopersicon esculentum (tomato)
  • Macroptilium spp.
  • Malva parviflora (small flowered mallow) and other Malva spp.
  • Mercurialis ambigua (common name unknown)
  • Phaseolus vulgaris (beans)
  • Physalis spp.
  • Polygonum spp. (knot weed or wire weed)
  • Sida spp.
  • Solanum nigrum (blackberry nightshade)
  • Solanum luteum (=Solanum villosum, hairy nightshade)
  • Wissadula spp.

TYLCV symptoms on bean

TYLCV (sever strain) infection on bean leaves has symptoms of yellow mosaic, crumpled, thickened and curl upwards or downwards leaflets (Figure 3). Apical and side shoots show abnormal growth (Figure 3). Fruit production is severely limited under glasshouse conditions.

Younger plants seem to be more susceptible to TYLCV or perhaps more attractive to the vector and hence the disease is more severe on plant infected at this stage. When grown together, tomato plants seem to be more susceptible than bean plants to TYLCV (Papayiannis et al 2007).

Foliage effects on bean plants caused by TYLCV

Epidemiology of TYLCV

TYLCV infected plants tend to be found randomly or in patches in a crop.

Overseas, all greenhouses infested with high populations of Bemisia tabaci have tomatoes infected with TYLCV. Autumn grown crops were the worst infected with TYLCV and crop losses were described as ‘drastically reduced’.

Distribution of TYLCV

TYLCV originated in the eastern Mediterranean in the 1960’s and spread worldwide, becoming a serious problem for tomato production.

The world-wide spread of TYLCV is suspected to be associated with the movement of commercial tomato and ornamental plants contaminated with virus infected whitefly.

It was eradicated from the Netherlands in 2008.

TYLCV was first detected in Australia in early 2006 in Brisbane on cherry tomatoes and in Bundaberg in both commercial and home garden tomatoes. TYLCV is also present in the Northern Territory.

Distinguishing TYLCV from other conditions

TYLCV can be confused with other diseases and disorders.

List of disease and disorder symptoms similar to TYLCV (Walker 2006)

Disease or disorder

Symptom description

Tomato big bud

Produces big buds and green flowers

Tomato yellow top virus

Leaflets are reduced in size and rounded with yellowish down-curled or up-curled margins

Physiological leaf roll (water stress)

Young expanding leaves are soft, not rigid and stunting is absent

Phosphate deficiency

Purplish tinge to whole plant, stiff and stunted plants

Magnesium deficiency

Interveinal yellowing of middle and lower leaves

References

Czosnek H, 2020. Tomato yellow leaf curl virus (leaf curl). Crop Protection Compendium. Wallingford, UK: CABI. DOI:10.1079/CPC.55402.20210104831

Navas-Castillo J, Sanchez-Campos S, Diaz JA, 1999. Tomato yellow leaf curl virus causes a novel disease of common bean and severe epidemics in tomato in Spain. Plant Disease, 83:29-32.

Papayiannis, LC, Paraskevopoulos, A, Katis, NI, 2007. First report of Tomato yellow leaf curl virus infecting common bean (Phaseolus vulgaris) in Greece. Plant Disease, 91(4), 465. doi: 10.1094/PDIS-91-4-0465C

Walker K, 2006 Tomato yellow leaf curl virus (TYLCV) (Tomato yellow leaf curl virus (TYLCV) Begomovirus)

Photo credits

Figure 1 John Thomas, Queensland Department of Industries and Fisheries

Figure 2 W. Billen, Pflanzenbeschaustelle, Weil am Rhein, Bugwood.org

Figure 3 Navas Castillo et al.

Page last updated: 01 Oct 2021