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Molecular resolution of genetic variability of major sweetpotato viruses and improved diagnosis of potyviruses co-infecting sweetpotato

Tairo, Fred (2006). Molecular resolution of genetic variability of major sweetpotato viruses and improved diagnosis of potyviruses co-infecting sweetpotato. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2006:5
ISBN 91-576-7054-4
[Doctoral thesis]

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The studies presented in this thesis contribute to improved resolution of genetic variability and diagnosis of potyviruses co-infecting sweetpotatoes. The most prevalent viruses infecting sweetpotato in Tanzania were Sweet potato feathery mottle virus (SPFMV), Sweet potato mild mottle virus (SPMMV), Sweet potato chlorotic stunt virus (SPCSV) and Sweet potato chlorotic fleck virus (SPCFV). They were serologically detected and results confirmed by RT-PCR and sequencing. Nucleotide (nt) sequences of the 3´-proximal genomic part of SPFMV and SPMMV and partial HSP70h gene of SPCSV isolates from Tanzania and Uganda were determined. Results revealed limited genetic variability among East African (EA) isolates for SPFMV and SPCSV but high variability for SPMMV. Phylogenetic analysis grouped Tanzanian and Ugandan isolates into an EA strain for SPFMV and SPCSV. Phylogenetically, four strains of SPFMV were detected: EA, RC and O, and strain C which is distantly related to them. SPCSV isolates were grouped into two distantly related strains: EA group with only East African isolates, and a non-East African (NEA) group with isolates from West Africa and other parts of the world. No distinct strain groups could be inferred among the SPMMV isolates from East Africa In Australia, Sweet potato virus Y (SPVY; synonymous to SPV-2) (family Potyviridae) was found to co-infect sweetpotatoes with strains RC and/or C of SPFMV. Five SPVY and SPFMV isolates were sequence-characterised for their 3’-proximal end of the genome and compared with isolates from Asia, Africa, Europe and North America. Phylogenetic analysis showed that Australian SPVY isolates formed a separate clade closest to the North American isolates. Utilising findings of molecular resolutions of major viruses in East Africa and Australia, a simple and sensitive RT-PCR/RFLP based diagnostic procedure was devised to differentiate potyviruses in complexes which readily differentiated SPVY and strains C and RC of SPFMV.

Authors/Creators:Tairo, Fred
Title:Molecular resolution of genetic variability of major sweetpotato viruses and improved diagnosis of potyviruses co-infecting sweetpotato
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :February 2006
Number of Pages:51
ALLI. Tairo, F., Kullaya, A. & Valkonen, J.P.T. 2004. Incidence of viruses infecting sweetpotato in Tanzania. Plant Disease 88, 916-920. II. Mukasa, S.B., Tairo, F., Kreuze, J.F., Kullaya, A., Rubaihayo, P.R. & Valkonen, J.P.T. 2003. Coat protein sequence analysis reveals occurrence of distinct strains of SPFMV in Uganda and Tanzania. Virus Genes 27, 49-56. III. Tairo, F., Mukasa, S.B., Jones, R.A.C., Kullaya, A., Rubaihayo, P.R. & Valkonen, J.P.T. 2005. Unravelling the genetic diversity of the three main viruses involved in Sweet Potato Virus Disease (SPVD) and its implications. Molecular Plant Pathology 6, 199-211. IV. Tairo, F., Jones, R.A.C. & Valkonen, J.P.T. 2005. Potyvirus complexes in sweetpotato: Occurrence in Australia, serological and molecular resolution, and phylogenetic analysis of the Sweet potato virus Y (SPV2) component (Submitted). Papers I, II, and III are reproduced with the kind permission from the publishers.
Place of Publication:Uppsala
ISBN for printed version:91-576-7054-4
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:F Plant production > F30 Plant genetics and breeding
H Protection of plants and stored products > H20 Plant diseases
Subjects:Not in use, please see Agris categories
Agrovoc terms:ipomoea batatas, sweet potatoes, plant diseases, potyviruses, viroses, genetic variation, molecular biology, east africa, tanzania, uganda, australia
Keywords:Keywords: Genetic variation, Sweet potato feathery mottle virus, Sweet potato virus Y, Sweet potato mild mottle virus, Sweet potato chlorotic stunt virus, Sweet potato chlorotic fleck virus, virus complex, virus diagnosis, RT-PCR/RFLP, Ipomoea batatas, sweetpotato.
Permanent URL:
ID Code:1040
Department:(NL, NJ) > Dept. of Plant Biology and Forest Genetics (until 131231)
Deposited By: fred tairo
Deposited On:21 Feb 2006 00:00
Metadata Last Modified:02 Dec 2014 10:09

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