Downloaded 357 times
Uploaded byBahuddin Zakariya University, Multan
Viral Disease of Plants
The document discusses various viral diseases affecting plants, particularly focusing on apple and citrus viruses, along with symptoms, transmission, and management strategies for each disease. It includes specific viruses such as apple mosaic virus, citrus tristeza virus, and banana bunchy top virus, detailing their host ranges and effects on productivity. Control measures emphasize the importance of using healthy propagated material and removing infected plants to mitigate the spread of these viral diseases.
More Related Content
Similar to Viral Disease of Plants
More from Bahuddin Zakariya University, Multan
Viral Disease of Plants
- 1. Department of AgricultureEntomology Bahauddin Zakariya University, Multan Viral Diseases of Plants By Muhammad Zeeshan Nazar B.Sc (Hons.) Agriculture Science Department of Entomology [email protected]
- 2. Distribution Apple mosaic virusis one of the oldest known and most widespread apple viruses. Occur in Bangladesh, Japan, Turkey, Africa, North and South America and many European countries. Host Range: 65 woody and herbaceous species in 19 families Apple mosaic Virus (Chestnut mosaic)
- 3. Symptoms • Infected treesdevelop pale to bright cream spots, bandings or patterns on leaves. • These spots may become necrotic after exposure to summer sun and heat. • Premature defoliation may occur when infection is severe. • Except in severe cases, infected trees can still produce a crop, with yield reductions from no reduction to 50%.
- 4. Transmission • Virus istransmitted by grafting, budding and by vegetative propagated rootstocks. • No reported insect vectors for the virus. Management • Use healthy propagated material • For inactivating the virus, cuttings, heat therapy • Heat treatment at 36OC for 3 to 10 weeks • Cross protection
- 5. Apple ringspot Distribution This diseasehas been known in New Zealand in 1935. Disease first described in 1954. Disease occurs only sporadically, so its economic importance is slight Host Range: Malus pumila, Chenopodium quinoa (Seed)
- 6. Symptoms • Small yellowspots, sometimes chlorotic rings on the leaves • Darker green spots or irregular rings on the fruits • The skin around the lesions light green or yellow color • In ripening fruit, the surface of the spots become rough and rusty. • No internal fruit symptoms. • Flavor and storage properties of the fruits are not affected. • The spots decrease their marketability
- 7. Transmission • Virus istransmitted by grafting, budding and by vegetative propagated rootstocks. Management • Use healthy propagated material • Removal of infected trees
- 8. Distribution • Widely distributedand best known of virus disease • Initially reports in Java in 1892 • Now occur in India, North and South America and many Pacific and Atlantic islands. Host range • Its host range is very wide. • Sugarcane, Maize, Sorghum, elephant grass etc. Mosaic of Sugarcane
- 9. • Symptoms • Firstsymptom appear about 6 weeks after planting • Primary and critical symptom is appearance of pale patches or blotches in green tissue of leaves • Patches are oval or elongated lying parallel to midrib • Tillers become erect, stiff and crinkled • Mottling of stem also occur lead to death of cells
- 10. Transmission Transmission by diseasecane sets used as seed. About 7 species of aphid are involved in virus transmission Control measures • Use of selected healthy sets for seed • Heat therapy is effective against certain strains • Elimination of the grass hosts • Use resistant or tolerant varieties.
- 11. Apple flat virus Distribution Thisdisease has been known in Spain, New York, America, Eastern Washington and Hood River Oregon. Host Range: Malus pumila and Cherry
- 12. Symptoms • This maycause cell death at the graft union • The resulting symptoms are those of decline, collapse, or tree breakage. • Fruits are smaller, flatter, and show a tendency for the calyx end to be open. Management •Plant virus-indexed trees. •If replanting in virus-infected areas of the orchard, use both rootstocks and scions that are tolerant of the virus.
- 13. Causative organisms andTransmission • These diseases are caused by Flat Apple Virus. • This virus is transmitted by nematodes, Xiphinema americanum. • Management • Use virus-tested certified material. • Use a disinfectant on contaminated pruning or cutting equipment. • Temperature therapy of infected stock
- 14. Distribution CTV is oneof the well known and most widespread citrus virus. Occur in Spain, France, Japan, Florida, Australia and US Host Range: CTV infects several species of the plant genus, Citrus, orange ,sweet orange, grapefruit, lime and Seville. Citrus Tristeza Virus
- 15. Symptoms • CTV symptomsare associated with viral disruption of phloem and its function. • There are three distinct syndromes of CTV infection: quick decline, stem pitting, and seedling yellows. • Affects the cambium layer below the bud union and prevents the normal development of cambium cells • In severe case, leaving fruit shriveled on the tree and leaves brown and dehydrated.
- 16. Transmission • Citrus tristezavirus (CTV) is transmitted by several aphid species in a semi- persistent manner Management • Use tolerant scion varieties for stem pitting. • Avoid illegally import citrus material. • Infected trees must be removed immediately
- 17. Distribution Occur in India,Congo, Kerala State, Irian Jaya, Indonesia, Host Range: BBTV infects several species of the plant genus, Citrus, orange ,sweet orange, grapefruit, lime and Seville. Banana Bunchy Top
- 18. Symptoms • Disease maybecome apparent at any stage • Symptoms appear in the second leaf to emerge after inoculation • Few dark-green streaks or dots on the minor veins on the lower portion of the lamina. • The leaf display whitish streaks along the secondary veins. • These streaks become dark green. • Leaves become smaller, both in length and in width of the lamina • Abnormal shape of fruit produced.
- 19. Transmission • Virus istransmitted by banana aphid Pentalonia nigronervosa. Management • Eradication of diseased plants • Spraying with power kerosene or parathion to control aphid population, vector of bunchy top.
- 20. Distribution This virus isspread worldwide, particularly in Europe Host range • Its host range is very wide. • Bean, melon, cucumber, tulip Tobacco Necrosis Virus
- 21. Symptoms • Brown necroticspots appear near the veins, they may be coalescing. • Occasionally young seedlings die. • dark sunken lesions formed on • On mature plants, the symptoms are mainly located on the lower leaves.
- 22. Transmission • TNV istransmitted by zoo spores of the fungus . • The vector properties of the fungus can be attributed to absorption of virus particles to the membrane of zoo spore. Control measures • Sterilization of soil if herbaceous host are grown in green house.
- 23. Distribution • reported inIndia, Canada, Russia, South Africa and all over the world. • it causes 16 to 64% losses in tuber yield Host range • Potato and also attack on tomato but no economically Leaf roll of Potato
- 24. Symptoms • The leafletsof infected plant roll up along margin • In infected seed tubers, Rolling of leaves starts in the lower leaves and progresses upward • Rolled leaflets become stiff, rigid, thick and leathery. • Internodes are shorts resulting in dwarfing or stunting of entire plant, • Necrosis occur in primary phloem
- 25. Transmission Infected seed tubersand some aphid species Control measures • Use of selected healthy seed tubers for seed • Heat therapy is effective against certain strains • Use resistant or tolerant varieties.
- 26. Distribution • In Asiaand Africa the major disease of cotton is caused by the Cotton leaf curl • This virus devastated the Pakistan cotton industry in early 1990s where it caused an estimated yield reduction of 30-35%. Host range Tomato, pepper, eggplant, okra, tobacco, beans, cotton and cucurbits Cotton Leaf Curl Virus
- 27. Symptoms • Upward ordownward curling of leaf. • Vein thickening is shown by the leaves • Infected plants become dark green in color. • Plants become stunted in growth with no proper yield • Petioles become twisted or deform
- 28. Transmission This disease istransmitted by whitefly Control measures • Use resistant or tolerant cultivars • Protect seedlings from whiteflies • Immediately remove infected-looking plants and bury them • Do not plant cotton near tomato or other crops susceptible to whiteflies • Use acephate at every seven days. • Practice crop rotation by planting crops that are not susceptible to whitefly
- 29. Apple dapple virus Distribution Thisdisease has been known in China and Japan Host Range: Malus pumila
- 30. Symptoms • Affected fruitbears small circular spots near the calyx end of the fruit. • As the fruit matures, the spots enlarge and the spots increase • In severe case of scar skin, the circular patches become brown and necrotic appear on the fruit. • The affected fruit is smaller than fruit of unaffected trees.
- 31. Causative organisms andTransmission • These diseases are caused by Apple scar skin viroid. • Virus can be transmitted from wooly plant by grafting and budding • Management Use virus-tested certified material. Use a disinfectant on contaminated pruning or cutting equipment. Temperature therapy of infected stock
- 32. References • Ong, ca.And Y. Dool . 1988. Virus Diseases of Malaysian Fruit Trees. Seminar on ttopicalfmitscultivation and pest & disease management, Kota • Niyeogere, c. 2012. Occurrence and Distribution of Banana Bunchy Top Disease. Tree and Forestry Science and Biotechnology • Adsuar, J. 1950. On the Physiacal properties of Sugarcane mosaic virus. Phytopathology 40: 214-215 • Singh, R.G. Plant disease 9th edition • Naimat, M. Virus Disease of Plants