Comparison of <i>Fusarium oxysporum</i> fsp <i>lycopersici</i> races 1, 2 and 3, and f.sp <i>radicis lycopersici</i> based on the sequences of fragments of the ribosomal DNA intergenic spacer region

Abstract

Sequence analysis of genomic fragments from the intergenic spacer region from three isolates of Fusarium oxysporum fsp lycoperisci and fsp radicis lycopersici was carried out using the big dyeterminator sequencing procedure. Two conditions of the DNA templates were also evaluated for their influence on the outcome of the terminator reaction. Results showed that sequencing using the PCR products of M13 primer reaction with either direct E. coli colony, (condition 1) or purified plasmid DNA as templates (condition 2), were successful and the sequences of the cloned IGS fragments were the same indicating that time and cost could be minimized by excluding the plasmidpurification steps. Based on the sequence analysis of the IGS fragment of race 1 (kis-1a) (ca. 638 bp including the forward and reverse primers sequences) it is observed that there is at least 95% similarity between the F. oxysporum races 1, 2, 3, and rly. Using the BioEdit sequence analysis program, there are 14 conserved regions with the longest continuous consensus segment being between nucleotide position number 1 and 129. Region 2 has 18 segment length (164-181), whileregion 3 is the shortest region with 15 segment length (183-197).