title: Mapping the distribution of maize streak virus genotypes across the forest and transition zones of Ghana.
abstract: Throughout sub-Saharan Africa, maize streak virus strain A (MSV-A), the causal agent of maize streak disease (MSD), is an important biological constraint on maize production. In November/December 2010, an MSD survey was carried out in the forest and transition zones of Ghana in order to obtain MSV-A virulence sources for the development of MSD-resistant maize genotypes with agronomic properties suitable for these regions. In 79 well-distributed maize fields, the mean MSD incidence was 18.544 % and the symptom severity score was 2.956 (1 = no symptoms and 5 = extremely severe). We detected no correlation between these two variables. Phylogenetic analysis of cloned MSV-A isolates that were fully sequenced from samples collected in 51 of these fields, together with those sampled from various other parts of Africa, indicated that all of the Ghanaian isolates occurred within a broader cluster of West African isolates, all belonging to the highly virulent MSV-A1 subtype. Besides being the first report of a systematic MSV survey in Ghana, this study is the first to characterize the full-genome sequences of Ghanaian MSV isolates. The 51 genome sequences determined here will additionally be a valuable resource for the rational selection of representative MSV-A variant panels for MSD resistance screening.
authors.affiliation: CSIR-Crops Research Institute, P.O. Box 3785, Kumasi, Ghana, alnopp@yahoo.co.uk.
authors.forename: Allen
authors.initials: A
authors.lastname: Oppong
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Offei
authors.forename: Kwadwo
authors.initials: K
authors.lastname: Ofori
authors.forename: Hans
authors.initials: H
authors.lastname: Adu-Dapaah
authors.forename: Joseph N L
authors.initials: JN
authors.lastname: Lamptey
authors.forename: Brigitta
authors.initials: B
authors.lastname: Kurenbach
authors.forename: Matthew
authors.initials: M
authors.lastname: Walters
authors.forename: Dionne N
authors.initials: DN
authors.lastname: Shepherd
authors.forename: Darren P
authors.initials: DP
authors.lastname: Martin
authors.forename: Arvind
authors.initials: A
authors.lastname: Varsani
mesh_terms: D001483:Base Sequence; D004270:DNA, Circular / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D065928:Forests; D016679:Genome, Viral / Q000235:genetics*; D005838:Genotype; D005869:Ghana; D026762:Maize streak virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D058974:Phylogeography; D010935:Plant Diseases / Q000821:virology*; D018515:Plant Leaves / Q000821:virology; D017422:Sequence Analysis, DNA; D003313:Zea mays / Q000821:virology*
chemical_list: D004270:DNA, Circular; D004279:DNA, Viral