A survey of cassava plants in the coastal region of Tanzania showing severe symptoms of cassava mosaic disease
Cassava (Manihot esculenta Crantz) is a root crop that plays an important role in many households in Africa. It is sometimes called “Africa´s food insurance”. The advantages with the crop are that cassava is drought-resistant and it can grow in a semi-dry land. It is a perennial crop and does not re...
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| Formato: | M2 |
| Lenguaje: | Inglés sueco |
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SLU/Dept. of Plant Biology and Forest Genetics (until 131231)
2012
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| Materias: |
| _version_ | 1855570796505726976 |
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| author | Sidstedt, Maja |
| author_browse | Sidstedt, Maja |
| author_facet | Sidstedt, Maja |
| author_sort | Sidstedt, Maja |
| collection | Epsilon Archive for Student Projects |
| description | Cassava (Manihot esculenta Crantz) is a root crop that plays an important role in many households in Africa. It is sometimes called “Africa´s food insurance”. The advantages with the crop are that cassava is drought-resistant and it can grow in a semi-dry land. It is a perennial crop and does not require much labor. Moreover, it can grow on low soil fertility and the roots can remain in the ground until needed. The cassava production has some constraints, however. Several diseases and pests can limit the production. The major diseases causing the largest losses in cassava production are cassava mosaic disease (CMD), cassava brown streak disease (CBSV) and bacterial blight disease. CMD is caused by begomovirus infection and the symptoms are overall dwarfing of the plants with curled leaves. Today, there are some varieties of cassava, which are resistant to CMD and a lot of work has been performed to achieve a crop that farmers can rely on. However, there are still a lot of diseased plants in the fields. In this report, a small survey of 33 fields in the coastal region was carried out with plants that had severe symptoms of CMD. The aim with this project is to test if recently appearing severe disease symptoms in cassava are associated with any new genotypes of cassava mosaic begomoviruses (CMBs). Among the 33 samples, there were differences in the Restriction Fragment Length Polymorphism (RFLP) pattern for the begomovirus amplification products. Five of the amplification products were selected and sent for sequencing of the DNA-B genomic component. The sequence results showed that two of the cassava samples with very severe symptoms of CMD were infected with virus isolates of East African cassava mosaic Zanzibar virus (EACMZV) and the other samples with East African cassava mosaic virus (EACMV). |
| format | M2 |
| id | RepoSLU5155 |
| institution | Swedish University of Agricultural Sciences |
| language | Inglés swe |
| publishDate | 2012 |
| publishDateSort | 2012 |
| publisher | SLU/Dept. of Plant Biology and Forest Genetics (until 131231) |
| publisherStr | SLU/Dept. of Plant Biology and Forest Genetics (until 131231) |
| record_format | eprints |
| spelling | RepoSLU51552013-01-04T13:23:05Z A survey of cassava plants in the coastal region of Tanzania showing severe symptoms of cassava mosaic disease Sidstedt, Maja cassava mosaic disease cassava mosaic begomoviruses Tanzania rolling circle amplification Restriction Fragment Length Polymorphism Cassava (Manihot esculenta Crantz) is a root crop that plays an important role in many households in Africa. It is sometimes called “Africa´s food insurance”. The advantages with the crop are that cassava is drought-resistant and it can grow in a semi-dry land. It is a perennial crop and does not require much labor. Moreover, it can grow on low soil fertility and the roots can remain in the ground until needed. The cassava production has some constraints, however. Several diseases and pests can limit the production. The major diseases causing the largest losses in cassava production are cassava mosaic disease (CMD), cassava brown streak disease (CBSV) and bacterial blight disease. CMD is caused by begomovirus infection and the symptoms are overall dwarfing of the plants with curled leaves. Today, there are some varieties of cassava, which are resistant to CMD and a lot of work has been performed to achieve a crop that farmers can rely on. However, there are still a lot of diseased plants in the fields. In this report, a small survey of 33 fields in the coastal region was carried out with plants that had severe symptoms of CMD. The aim with this project is to test if recently appearing severe disease symptoms in cassava are associated with any new genotypes of cassava mosaic begomoviruses (CMBs). Among the 33 samples, there were differences in the Restriction Fragment Length Polymorphism (RFLP) pattern for the begomovirus amplification products. Five of the amplification products were selected and sent for sequencing of the DNA-B genomic component. The sequence results showed that two of the cassava samples with very severe symptoms of CMD were infected with virus isolates of East African cassava mosaic Zanzibar virus (EACMZV) and the other samples with East African cassava mosaic virus (EACMV). Kassava är en rotfrukt som spelar en viktig roll i många hushåll i Afrika och kallas ibland för ”Afrikas matförsäkran”. Det som gör kassava till en fördelaktig gröda är att den är torktålig, inte kräver särskilt stor arbetsinsats, kan växa i näringsfattiga jordar samt att rotknölarna kan vara kvar i jorden och skördas vid behov. Produktionen av kassava hålls dock tillbaka av olika hinder såsom flera sjukdomar och skadegörare vilket påverkar avkastningen negativt. De största problemen som står för de största förlusterna av kassavaproduktionen är: sjukdomen kassavamosaik (CMD som är en förkortning av det engelska namnet ”cassava mosaic disease”), kassavabrunröta (CBSD som är en förkortning av det engelska namnet ”cassava brown streak disease”) samt kassavabakterios (från engelskans ”bacterial blight”). CMD orsakas av begomovirusinfektion och symptomen är dvärgväxt, blad som skrumpnar samt mosaikmönster på bladen. Idag finns det en del sorter som är framtagna för deras resistens mot CMD och mycket arbete har lagts ner genom åren för att få fram en gröda som lantbrukarna kan lita på. Tyvärr är det fortfarande många sjuka plantor ute i fält och fattiga bönder som påverkas negativt. I denna rapport genomfördes en mindre undersökning där 33 fält i Tanzanias kustområde undersöktes och prover från plantor som uttryckte symptom av CMD samlades in. Målet med detta projekt var att med molekylärbiologiska metoder undersöka om nyligen observerade plantor som uppvisade starka symptom av CMD kunde associeras med nya genotyper av kassavamosaikvirus. Av de 33 prover som analyserades kunde olika typer identifieras med hjälp av en metod som kallas RFLP (Restriction Fragment Lenght Polymorphism). För fem av dessa prover sekvensbestämdes en del av DNA-B molekylen för jämförelse med andra publicerade isolat i GenBank. Resultatet visade att två av proven som samlats in från plantor som uttryckte svåra symptom var infekterade med East African cassava mosaic Zanzibar virus (EACMZV) medan de andra var infekterade med East African cassava mosaic virus (EACMV). SLU/Dept. of Plant Biology and Forest Genetics (until 131231) 2012 M2 eng swe https://stud.epsilon.slu.se/5155/ |
| spellingShingle | cassava mosaic disease cassava mosaic begomoviruses Tanzania rolling circle amplification Restriction Fragment Length Polymorphism Sidstedt, Maja A survey of cassava plants in the coastal region of Tanzania showing severe symptoms of cassava mosaic disease |
| title | A survey of cassava plants in the coastal region of Tanzania showing severe symptoms of cassava mosaic disease |
| title_full | A survey of cassava plants in the coastal region of Tanzania showing severe symptoms of cassava mosaic disease |
| title_fullStr | A survey of cassava plants in the coastal region of Tanzania showing severe symptoms of cassava mosaic disease |
| title_full_unstemmed | A survey of cassava plants in the coastal region of Tanzania showing severe symptoms of cassava mosaic disease |
| title_short | A survey of cassava plants in the coastal region of Tanzania showing severe symptoms of cassava mosaic disease |
| title_sort | survey of cassava plants in the coastal region of tanzania showing severe symptoms of cassava mosaic disease |
| topic | cassava mosaic disease cassava mosaic begomoviruses Tanzania rolling circle amplification Restriction Fragment Length Polymorphism |