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BANANA BRACT MOSAIC VIRUS DISEASE (BBrMV)

BANANA BRACT MOSAIC VIRUS DISEASE (BBrMV) . LYDIA V. MAGNAYE. BRACT MOSAIC . The Disease:. One of the more recently described virus diseases of banana First noted in Mindanao, Philippines in 1979

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BANANA BRACT MOSAIC VIRUS DISEASE (BBrMV)

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  1. BANANABRACT MOSAICVIRUS DISEASE(BBrMV) LYDIA V. MAGNAYE

  2. BRACT MOSAIC The Disease: • One of the more recently described virus diseases of banana • First noted in Mindanao, Philippines in 1979 • Given the name bract mosaic based on characteristic symptoms described by Magnaye at the International meeting of banana virologists at PCARRD Los Banos in 1988.

  3. BRACT MOSAIC The Disease: • Included in the list of viruses of quarantine importance (Frison and Putter,1999) • Affects many local cultivars but is most common in Saba and Cardaba(BBB) • Cultivars in Cavendish sub-group (AAA) in commercial plantations also affected

  4. Causal Pathogen: • Nucleotide sequence analysis indicates the • BBrMV is potyvirus • transmitted by 3 spp. of aphid Vector in non- • persistent manner • Transmission in nature : by Aphids - Rhopalosiphum midis (corn aphid) Aphis gossypii (cotton aphid) Pentalonia nigronervosa (banana/brown aphids

  5. Aphids pick up the virus when they suck sap from infected plant then pass it on when they feed healthy one: • Field spread ∙ Use of infected plant materials ∙ subsequent spread by both * Aphid vectors * propagation of infected plant material

  6. Importance: • The disease was first observed and suspected to be distinct from mosaic caused by CMV in 1979 on cultivar Canara, Binawi, Pisang Maduranga and Morado. • has subsequently been shown on established plantings of Saba and Cardaba (Magnaye,1998)

  7. Recorded incidence in commercial plantations ∙ Subasta, West of Davao at Guianga – 80 % of virus infection due to BBrMV ∙ Mandug – 20% ∙ Kapalong – 5 % ∙ Also present – areas around Davao City and General Santos City, South Cotabato (25,000 mats eradicated in late 1988 due to BBrMV)

  8. ∙ A company around Davao City – 45, 000 mats eradicated – 1983-84 • Geographical Distribution: • > Recorded in Sri Lanka, India Samoa, • Vietnam, Philippines

  9. Why virus has been able to spread • Growers not aware of the symptoms • Effects not dramatic as Bunchy Top(BT) • Infected plants still produce bunches

  10. Why virus has been able to spread • Need to facilitate transfer of technical information on the disease • It seems clear that some crop protection intervention may not be feasible to outright adoption like eradication of diseased plants

  11. Symptoms Chlorotic, sometimes dark green streak along petiole Infected Healthy May or may not show leaf symptoms, if it does, thickening of vein and chlorotic streak may progress into severe mosaic pattern Abnormal thickening of veins

  12. Symptoms Suckers Infected Mature plants Tissue Culture Plantlets

  13. Symptoms • Streak on the bunch stalk • Distinct dark streak on the inflorescence • Bunches shorter and hands more compact • Not well develop finger and fruit blemishes/streaking

  14. Symptoms • Following the removal of dried leaf sheaths, spindle-shaped streak and stripes is diagnostic of the disease

  15. Measures for Disease Management • Disease –free planting materials is the first step • in disease control. • Tissue culture an important technology for • production of disease-free, high quality • planting materials and rapid propagation of • many uniform plants • However, viruses can be readily transmitted • through tissue culture process if the source of • explants are infected

  16. Measures for Disease Management • Micropropagated plants-not automatically • virus-free. Banana bract mosaic ( BBrMV) is • not eliminated by tissue culture hence • infection maybe passed on to subsequent • propagation • Thus Virus Indexing Technology is an essential component of virus- free seedling production

  17. Measures for Disease Management • To establish a program for virus free banana • tissue culture plantlets: • > know kinds of virus present in the farm • to select the suitable method for • detection

  18. Rouging/Sanitation programs: > Early detection and outright elimination of infected plants, alternate host and vector host > Sanitation( deleafing and stem sanitation) > Best to use indexed virus – free materials to new areas > Has the issue of eradication for banana virus diseases been answered? > This could be of outmost concern because virus disease-free seedlings are only practical if they can be isolated from infected plants and vector

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