Bs. Goodman et al., A survey of South African sugarcane mosaic virus (SCMV) strains based on coat protein gene sequence analysis, PROCEEDINGS OF THE SEVENTY-SECOND ANNUAL CONGRESS OF THE SOUTH AFRICAN SUGAR TECHNOLOGISTS' ASSOCIATION, 1998, pp. 146-148
Sugarcane mosaic potyvirus (SCMV) infection can severely reduce sucrose yie
ld in susceptible sugarcane varieties in South Africa. Knowledge of prevale
nt South African strains of SCMV is poor but strategically important for th
e development of better diagnostic procedures and transgene induced resista
nce. Since most strain variation resides in the capsid structure, molecular
analysis of relative homology in nucleotide and inferred amino acid sequen
ces in the most variable (N-terminal) coat protein region is the method of
choice for distinguishing strains. Total RNA was extracted from symptomatic
leaves collected from various regions. Viral RNA was reverse transcribed a
nd a large fragment at the 3' end of the SCMV genome amplified by PCR using
previously designed primers. Fragments, both cloned and uncloned, were cyc
le sequenced using dye terminator chemistry. Analysis of the sequences was
performed using an ABI Prism 310 Genetic Analyser and related computer soft
ware. Consensus sequences of the first 240-360 bases of the coat protein ge
ne were obtained and compared against international databases. The results
indicate that SCMV strains in South Africa belong to the SC, E and A cluste
r.