Molecular variability and distribution of cassava mosaic begomoviruses in Nigeria

• Published in: Journal of phytopathology Vol. 153; no. 4; pp. 226 - 231
• Main Authors: Ariyo, O.A, Koerbler, M, Dixon, A.G.O, Atiri, G.I, Winter, S
• Format: Journal Article
• Language: English
• Published: Berlin, Germany Blackwell Verlag GmbH 01.04.2005; Blackwell
• Subjects: African cassava mosaic virus; Begomovirus; Biological and medical sciences; cassava; Cassava mosaic disease; East African cassava mosaic Cameroon virus; East African cassava mosaic virus; Fundamental and applied biological sciences. Psychology; geographical distribution; Manihot esculenta; molecular sequence data; nucleotide sequences; Phytopathology. Animal pests. Plant and forest protection; Plant viruses and viroids; savannas; sequence analysis; Nigeria; Cameroon; Ivory Coast; Africa; African cassava mosaic virus; Mixed infection; Microbiology; Nucleotide sequence; Manihot esculenta; East African cassava mosaic Cameroon virus; Begomovirus; Strain; Virus; Polymerase chain reaction; Vegetable crop; Dicotyledones; Angiospermae; Euphorbiaceae; Isolate; Geminiviridae; Spermatophyta; Tuber plant; Detection; Genome; Cassava mosaic disease
• ISSN: 0931-1785; 1439-0434
• DOI: 10.1111/j.1439-0434.2005.00958.x

Several begomovirus species and strains causing Cassava mosaic disease (CMD) have been reported from cassava in Africa. In Nigeria, African cassava mosaic virus (ACMV) was the predominant virus in this important crop, and East African cassava mosaic virus (EACMV), first reported from eastern Nigeria in 1999, was also found occasionally. A survey was conducted in 2002 to resolve the diversity of the virus types present in cassava in Nigeria and to further understand the increasing complexity of the viruses contributing to CMD. A total of 234 leaf samples from cassava with conspicuous CMD symptoms were collected in farmers’ fields across different agroecological zones of Nigeria and subjected to polymerase chain reaction (PCR) with type‐specific primers. In addition and, to provide a full characterization of the viruses present, DNA‐A genome components of several viruses and informative genome fragments were sequenced. In Nigeria, ACMV proved to be the dominant virus with 80% of all samples being positive for ACMV. The East African cassava mosaic Cameroon virus (EACMCV) prevalent in Cameroon and Ivory Coast was detected in single infections (2%) and in mixed infections (18%) with ACMV. There was no indication for other virus strains of EACMV present in the country. The EACMCV samples collected showed a high nucleotide sequence identity >98% and resembled the described sequence of a Cameroon isolate (EACMCV‐CM) more than an Ivory Coast isolate, EACMCV‐CM[CI]. Evidence is provided that the EACMCV has reached epidemiological significance in Nigeria.