Genetically distinct strains of Cassava brown streak virus in the Lake Victoria basin and the Indian Ocean coastal area of East Africa

Department of Applied Biology, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland.
Archives of Virology (Impact Factor: 2.39). 02/2009; 154(2):353-9. DOI: 10.1007/s00705-008-0301-9
Source: PubMed


Six isolates of Cassava brown streak virus (CBSV, genus Ipomovirus; Potyviridae) from the Lake Victoria basin in Uganda and Tanzania were characterized. Virus particles were 650 nm long. The complete coat protein (CP)-encoding sequences (1,101 nucleotides, nt) were 90.7-99.5 and 93.7-99.5% identical at the nt and amino acid (aa) levels, respectively. The 3' untranslated region was 225, 226 or 227 nt long. These eight isolates were only 75.8-77.5% (nt) and 87.0-89.9% (aa) identical when compared to the partial CP sequences (714 nt) of six CBSV isolates characterized previously from the costal lowlands of Tanzania and Mozambique. Hence, two genetically different and geographically separated populations of CSBV exist in East Africa.

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Available from: Yan-Ping Tian, Apr 19, 2014
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    • "Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License endemic virus, referred to as cassava brown streak uganda virus (UCBSV) (Mohammed et al., 2012). Both species belong to the genus Ipomovirus, family Potyviridae (Mbanzibwa et al., 2009a, b). Typical symptoms of the disease include; interveinal chlorosis on the leaves, necrotic streak on the stem and brown or grey corky root necrosis. "
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    ABSTRACT: Cassava brown streak disease (CBSD) is the most devastating disease of cassava in southern, eastern and cntral Africa, and can cause up to 100% yield loss. Limited progress has been made in breeding for host plant resistance due to limited knowledge on the resistance variability to the disease. Reaction of promising cassava genotypes to CBSD in multi-environments are also unknown. Therefore, this study intended to: (1) Identify additional sources of resistance to CBSD; (2) Determine the stability of resistance to CBSD, and (3) mega-environments for screening resistance to CBSD. Field evaluation of 19 genotypes was conducted in RCBD with three replications at three agro-ecologies of Uganda for two cropping cycles. Additive Main Effects and Multiplicative Interaction (AMMI) and (GGE) biplot models were used to analyze genotype-environment interactions. Based on mean field reaction, the six best genotypes identified for resistance to CBSD were: TZ/06/140, TMS30572, TZ /06/130, N3/66/1, N3/58/1 with N3/104/3 and N3/66/1 being the most stable. While N3/66/1, N3/58/1 and N3/104/3, Mzungu and Kigoma Red were reported to be putative new sources of resistance to CBSD in Uganda. Genotypes (G), Environments (E), and GxE interactions were all significant, with no genotype exhibiting complete resistance. The significant result for GxE interaction to CBSD indicates the need for multi-environment screening and is suggestive of quantitative nature of CBSD resistance.
    Full-text · Article · Apr 2015
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    • "The pandemic was associated with up to 100-fold increases in the abundance of the whitefly vector (Legg and Ogwal, 1998). CBSD is caused by two viruses in the family Potyviridae, genus Ipomovirus (Mbanzibwa et al., 2009; Monger et al., 2001; 2010; Winter et al., 2010). The disease was initially restricted to lowland coastal areas of Kenya, Tanzania and Mozambique, as well as the surrounds of Lake Malawi in Tanzania and Malawi (Hillocks et al., 1999; Nichols, 1950; Legg and Raya, 1998), but from 2004 the spread of CBSD to higher altitudes and inland to countries surrounding the Great Lakes region was reported. "

    Full-text · Article · Jan 2015 · AFRICAN JOURNAL OF BIOTECHNOLOGY
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    • "The viruses causing CBSD belong to the genus Ipomovirus of the family Potyviridae, with characteristic pinwheel-like or cylindrical inclusions found in the phloem tissue, and with a positive-sense ssRNA genome of ~9 kb (Mbanzibwa et al., 2009a; Monger et al., 2001). The family Potyviridae is among the largest of the families of plant viruses, consisting of six genera, distinguished based upon their genomic organization, sequence relatedness and insect vector (Fauquet, 2007). "
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    ABSTRACT: Cassava brown streak disease (CBSD) has emerged as the most important viral disease of cassava (Manihot esculenta) in Africa and is a major threat to food security. CBSD is caused by two distinct species of ipomoviruses, Cassava brown streak virus and Ugandan cassava brown streak virus, belonging to the family Potyviridae. Previously, CBSD was reported only from the coastal lowlands of East Africa, but recently it has begun to spread as an epidemic throughout the Great Lakes region of East and Central Africa. This new spread represents a major threat to the cassava-growing regions of West Africa. CBSD-resistant cassava cultivars are being developed through breeding, and transgenic RNA interference-derived field resistance to CBSD has also been demonstrated. This review aims to provide a summary of the most important studies on the aetiology, epidemiology and control of CBSD and to highlight key research areas that need prioritization. © 2015 The Authors.
    Full-text · Article · Dec 2014 · Journal of General Virology
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