Tobacco ringspot virus
|Tobacco ringspot virus|
|TRSV symptoms on potato leaves|
|Species:||Potato yellow vein virus|
|Confirmed cases of TRSV (blue) and unconfirmed (light blue)|
|Nicotiana virus 12
Plants are most severely affected when they are infected young (less than 5 weeks old or from seed), the virus spreading systemically in the plant. The terminal bud is curved to form a crook (bud blight), and other buds become brown, necrotic and brittle. Brown streaks can be seen in the pith of stems and branches, and occasionally on petioles and leaf veins. Leaflets are dwarfed and rolled. Pods develop poorly and late.
TRSV causes ring and line patterns on the foliage and stunting.
Leaves are mottled and stunted, and fruits are deformed.
Plants show symptoms of decline, exactly as with Tomato ringspot virus, i.e. new growth is weak and sparse, internodes are shortened, leaves are small and distorted, and plants are stunted. Berries are sparse and develop unevenly.
Plant shows stem dieback and stunting. On a susceptible cultivar such as Pemberton, leaves are deformed and somewhat thickened, become chlorotic and show necrotic spots, and may drop giving a shothole or tattered effect.
In cherry, in which the disease has only ever been seen in a few individual trees, young leaves show irregular chlorotic blotching over the whole leaf blade, and the leaf margins are deformed and lobed. These symptoms are seen in scattered leaves throughout the crown. Fruits mature late on infected trees.
For soyabeans, disease-free seeds should be used. For fruit crops, it is relatively easy to test for TRSV in potential mother plants and establish virus-free nuclear stock, to be propagataed and distributed through a certification scheme. In the areas where the American dagger nematode (Xiphinema americanum) vector does not occur, the problem of re-infection does not then arise. In North America, it may be necessary to test soil for vector nematodes, and if necessary treat with nematicides, before replanting with healthy stock, e.g. for blueberry. For most of the fruit crops, however, TRSV infection is so rare that no special measures are needed to prevent reinfection of healthy planting material.
- Data Sheets on Quarantine Pests Tobacco ringspot nepovirus. Retrieved: 04-01-11.
- Demski, J.W.; Kuhn, C.W. (1989) Tobacco ringspot virus. In: Compendium of soybean diseases (3rd edition), pp. 57-59. American Phytopathological Society, St. Paul, USA.
- Gooding, G.V. (1991) Diseases caused by viruses. In: Compendium of tobacco diseases, pp. 41-46. American Phytopathological Society, St. Paul, USA.
- Sinclair, J.B.; Walker, J.C. (1956) A survey of ringspot on cucumber in Wisconsin. Plant Disease Reporter 40, 19-20.
- Gonsalves, D. (1988) Tomato ringspot virus decline; tobacco ringspot virus decline. In: Compendium of grape diseases, pp. 49-51. American Phytopathological Society, St. Paul, USA.
- Ramsdell, D.C. (1987) Necrotic ringspot of blueberry. In: Virus diseases of small fruits, Agriculture Handbook No. 631, pp. 114-116. USDA/ARS, Washington, USA.
- Stace-Smith, R.; Hansen, A.J. (1974) Occurrence of tobacco ringspot virus in sweet cherry. Canadian Journal of Botany 52, 1647-1651.