{"id":13326,"date":"2026-06-20T12:27:05","date_gmt":"2026-06-20T12:27:05","guid":{"rendered":"https:\/\/dev.iita.org\/news-item\/researchers-solve-mystery-of-how-namikonga-farmers-variety-is-able-to-withstand-devastating-effects-of-deadly-viral-cassava-disease\/"},"modified":"2026-06-20T12:27:05","modified_gmt":"2026-06-20T12:27:05","slug":"researchers-solve-mystery-of-how-namikonga-farmers-variety-is-able-to-withstand-devastating-effects-of-deadly-viral-cassava-disease","status":"publish","type":"news-item","link":"https:\/\/iita.org\/fr\/news-item\/researchers-solve-mystery-of-how-namikonga-farmers-variety-is-able-to-withstand-devastating-effects-of-deadly-viral-cassava-disease\/","title":{"rendered":"Researchers solve mystery of how \u201cNamikonga\u201d farmers\u2019 variety is able to withstand devastating effects of deadly viral cassava disease"},"content":{"rendered":"<p class=\"wp-block-paragraph\"><em>Variety has a complex defense mechanism that limits the multiplication of the brown streak virus in their bodies \u00a0once infected<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Dar es Salaam. Scientists have now shed more light on how a farmers\u2019 variety in Tanzania is able to tolerate the deadly viral Cassava Brown Streak Disease (CBSD) disease after infection, showing limited symptoms  and impact on yield.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The team has established that &#8216;Namikonga&#8217; plants have a complex line of defense involving many biochemical pathways  and genes that are able to limit the virus multiplication in their bodies once infected. This, in turn, limits disease progression, restricting infection symptoms to the leaves only while allowing the normal root growth without the necrosis\u2014the dry brown rot associated with CBSD.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They have shared their findings in a paper \u201c<a href=\"https:\/\/www.nature.com\/articles\/s41598-017-09617-z\" target=\"_blank\" rel=\"noopener\">A time series transcriptome analysis of cassava (Manihot esculenta Crantz) varieties challenged with Ug andan cassava brown streak virus<\/a>,\u201d published this week in Scientific Reports, a journal of the Nature group.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">CBSD is currently a major threat to the production of cassava in East, Central,  and Southern Africa as it results in a dry brown rot in the roots making them unsuitable for any use  and can cause yield losses of nearly 100%.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u201cOur findings show that Namikonga resists the virus by restricting its multiplication in the plant. This gives us new hope in our efforts to control the disease  and revive cassava production,\u201d says Teddy Amuge, a Plant Scientist, the lead researcher who worked in collaboration with the International Institute of Tropical Agriculture (IITA), the Ug andan National Crop Resources Research Institute (NaCRRI), New York University,  and the University of Pretoria, South Africa.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The team has for years been studying two Tanzanian cassava varieties\u2014Namikonga  and Albert, that are resistant  and susceptible to cassava brown streak disease (CBSD), respectively.\u00a0 In Albert, the viral loads were higher  and infection with the virus caused substantial leaf chlorosis  and root necrosis. The study generated massive data that is now being mined further by several other research groups.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u201cWe are very excited by these results,  and are now working on approaches to allow plant breeders to quickly transfer this resistance into other, high yielding cassava varieties,\u201d says Morag Ferguson, corresponding author  and principal investigator of this research.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is the first large-scale study of how some cassava varieties are able to resist pests  and disease,  and this will help scientists to better control these pathogens.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u201cA better underst anding of this effect may help scientists plan more successful strategies for breeding CBSD resistant cassava in the future,\u201d says Dave Berger, a vital collaborator from the University of Pretoria.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">First reported in Tanzania, CBSD previously occurred at low levels primarily in coastal East Africa, Mozambique,  and around Lake Malawi  and was thought to be restricted by altitude. However in the early 2000s, CBSD began to spread around Lake Victoria,  and by 2004, typical CBSD symptoms were widespread in farmers\u2019 fields in central Ug anda. The disease has spread steadily since then as far as DR Congo  and South Sudan  and now, together with cassava mosaic disease, causes over US$1 billion losses in production annually in Africa.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The findings complement a similar study that identified markers associated with genes for resistance to both CBSD  and CMD in Namikonga  and Albert varieties, the findings of which were published in the journal Theoretical  and Applied Genetics.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"># # #<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u00c0 propos de l'IITA<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The International Institute of Tropical Agriculture (IITA) is a not-for-profit institution that generates agricultural innovations to meet Africa\u2019s most pressing challenges of hunger, malnutrition, poverty,  and natural resource degradation. Working with various partners across sub-Saharan Africa, we improve livelihoods, enhance food  and nutrition security, increase employment,  and preserve natural resource integrity. IITA is a member of CGIAR, a global agriculture research partnership for a food secure future.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For more information, please contact: Catherine Njuguna, IITA communication Officer for Eastern Africa, <a href=\"mailto:c.njuguna@cgiar.org\" target=\"_blank\" rel=\"noopener\">c.njuguna@cgiar.org<\/a> \/ Katherine Lopez, Head of Communication, <a href=\"mailto:k.lopez@cgiar.org\" target=\"_blank\" rel=\"noopener\">k.lopez@cgiar.org<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>Scientists have now shed more light on how a farmers\u2019 variety in Tanzania is able to tolerate the deadly viral Cassava Brown Streak Disease (CBSD) disease after infection, showing limited symptoms and impact on yield.<\/p>","protected":false},"featured_media":13327,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center 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