African Cassava Mosaic Virus: Etiology, Epidemiology, and Control

Fauquet, Claude; Fargette, Denis

doi:10.1094/pd-74-0404

Cited by 264 publications

(216 citation statements)

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“…In general, the disease severity recorded on local cassava varieties depended on the type of variety planted. Our observations corroborate with data reported by Fauquet and Fargette [20] who revealed that the severity of CMD symptoms varies with the cultivar and increases with the plant age until about 60 days after planting. These authors noted afterwards that the level of CMD severity depended on several factors such as the cultivar, climatic conditions, and growing season.…”

Section: Discussionsupporting

confidence: 93%

Assessing Reactions of Genetically Improved and Local Cassava Varieties to Cassava Mosaic Disease (CMD) Infection in a Savannah Region of the DR-Congo

Muengula-Manyi¹,

Mukwa²,

Nkongolo³

et al. 2013

AJPS

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The responses of eight genetically improved and eight local cassava varieties to cassava mosaic disease (CMD) were evaluated under field conditions at two sites, in Eastern Kasaï, region of the DR-Congo). The varieties were planted using randomized complete block design with three replications. The rate of cuttings sprouted varied significantly from variety to variety and from location to location. Local varieties were severely infected than improved varieties throughout the trial period. In general, the level of CMD incidence for genetically improved varieties was below 15% while it reached 100% for the local cassava varieties six months after planting (MAP). This trend was also observed for the CMD severity and gravity. The mean scores for CMD severity were 2 and 3.6 for genetically improved and local varieties, respectively at 6 MAP. CMD gravity for improved varieties was below 21% for genetically improved varieties and exceeded 85% for local varieties at the end of trials. Area Under the Severity index Progress Curve (AUSiPC) and Area Under Disease Progress Curve (AUDPC) estimates confirmed that improved varieties were moderately infested comparatively to local varieties. Molecular analysis is being conducted to determine the genetic variability and complexity of the cassava mosaic virus strains involved.

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Section: Discussionsupporting

confidence: 93%

Assessing Reactions of Genetically Improved and Local Cassava Varieties to Cassava Mosaic Disease (CMD) Infection in a Savannah Region of the DR-Congo

Muengula-Manyi¹,

Mukwa²,

Nkongolo³

et al. 2013

AJPS

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“…African cassava mosaic virus (ACMV) is the most prevalent pathogen of cassava in Africa (Fauquet & Fargette, 1990); it belongs to the genus Begomovirus (Stanley et al, 2005), and is transmitted by the whitefly Bemisia tabaci (Gennadius). Its bipartite genome consists of two circular single-stranded DNA molecules (DNA A and DNA B).…”

Section: Introductionmentioning

confidence: 99%

Disassembly of African cassava mosaic virus

Kittelmann

Jeske

2008

Journal of General Virology

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The plant-infecting geminiviruses encapsidate their single-stranded DNA genome in characteristic twinned particles that are unique among viruses. These particles are formed by joining two incomplete T51 icosahedra. African cassava mosaic virions were purified by densitygradient centrifugation from infected Nicotiana benthamiana plants and analysed for their stability with respect to pH changes and heat treatment by using electron microscopy. Negative staining and rotary shadowing revealed stable virions as well as isolated capsomeres between pH 4.0 and 8.5. At pH 9.0 and above, particles disintegrated, whereas they mainly aggregated at a pH below 6.0. Heating the preparations to 55 6C and above resulted in the complete loss of any discernible structure. A low proportion (approx. 10 %) of particles ejected their DNA within the pH range of 6.0-8.5. Most virions released their DNA at the top (15.9 %) or the shoulder (71.4 %) of the twin particles and only 12.7 % at the waist. Compared with the expected numbers of pentameric capsomeres at the top (9 %), the shoulder (45.5 %) or the waist (45.5 %), the results revealed a preferential DNA release from the top and shoulder of the geminate particle. INTRODUCTIONThe small plant pathogenic geminiviruses are distributed all over the world and have caused severe economic damages in tropical and subtropical countries (Moffat, 1999). African cassava mosaic virus (ACMV) is the most prevalent pathogen of cassava in Africa (Fauquet & Fargette, 1990); it belongs to the genus Begomovirus (Stanley et al., 2005), and is transmitted by the whitefly Bemisia tabaci (Gennadius). Its bipartite genome consists of two circular single-stranded DNA molecules (DNA A and DNA B). The three-dimensional structure of the geminate (twin) ACMV particles has been resolved by cryo-electron microscopy (EM) and image reconstruction (Böttcher et al., 2004). The two incomplete T51 icosahedra of the virion are formed by 110 copies of a single capsid protein (CP) with pentameric capsomere organization. Each half of the geminate particle is built up by 11 pentameric capsomeres, one pentamer missing to complete a T51 icosahedron. The two halves are joined at the place of the missing capsomeres, forming the waist of the particle (see Fig. 7). The two capsomeres at both ends of the particle with strict fivefold symmetry will be called the 'top capsomeres', the adjacent five capsomeres on each side of the virion with local fivefold symmetry will be called the 'shoulder capsomeres' and the five remaining capsomeres at the waist will be called the 'waist capsomeres' (see Fig. 7). The single CP possesses a molecular mass of 30.1 kDa and a calculated pI of 10.0. Each geminate particle encapsidates one circular DNA molecule so that two virions are needed for infection in case of bipartite geminiviruses.Encapsidating the viral genome, the geminivirus CP is important for insect transmission (Briddon et al., 1990; Höfer et al., 1997; Höhnle et al., 2001;Kheyr-Pour et al., 2000; Noris et al., 1998) and transport of the...

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“…There is a strong overlap between the geographic ranges of distribution of the African cassava mosaic virus (ACMV) and its only known vector, the sweet potato whitefl y, Bemisia tabaci (Gennadius) (Robertson 1987, Fauquet & Fargette 1990.…”

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Biological parameters of Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae) on Jatropha gossypiifolia, commercial (Manihot esculenta) and wild cassava (Manihot flabellifolia and M. carthaginensis) (Euphorbiaceae)

Carabalí¹,

Belloti²,

Montoya-Lerma³

2010

Neotrop. entomol.

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-Bemisia tabaci (Gennadius) is one of the most important pests of cassava in Africa and several countries of Asia due to the damage caused by direct feeding, the excretion of honeydew, and its capacity as a vector of cassava mosaic geminivirus. There is a general consensus that B. tabaci is a complex of morphologically indistinguishable populations with different biotypes. In the Americas, the polyphagous biotype B does not appear to feed on cassava. Recent studies indicate that it is possible, however, for biotype B to gradually adapt to cassava using phylogenetically related hosts. Therefore, the possibility that some wild species of cassava constitute intermediate hosts in the adaptation process may lead to the establishment of biotype B on commercial varieties of Manihot esculenta. In here, we evaluated Jatropha gossypiifolia, two wild species of cassava (Manihot fl abellifolia and M. carthaginensis) and a commercial cassava variety (MCol 2063) as hosts of biotype B. The highest oviposition rate (2.7 eggs /two days) occurred on M. esculenta, although the development time (44 d) was the longest when compared to M. carthaginensis and J. gossypiifolia. About 60% of the population could reproduce on the wild cassava species vs. 55% on J. gossypiifolia and 27.5% on the commercial variety. Our data suggest that J. gossypiifolia is a suitable host and the wild species M. carthaginensis can constitute a potential intermediate host in the adaptation of biotype B to commercial varieties of cassava.

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African Cassava Mosaic Virus: Etiology, Epidemiology, and Control

Cited by 264 publications

References 0 publications

Assessing Reactions of Genetically Improved and Local Cassava Varieties to Cassava Mosaic Disease (CMD) Infection in a Savannah Region of the DR-Congo

Assessing Reactions of Genetically Improved and Local Cassava Varieties to Cassava Mosaic Disease (CMD) Infection in a Savannah Region of the DR-Congo

Disassembly of African cassava mosaic virus

Biological parameters of Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae) on Jatropha gossypiifolia, commercial (Manihot esculenta) and wild cassava (Manihot flabellifolia and M. carthaginensis) (Euphorbiaceae)

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