Chromosomal polymorphism in Fusarium oxysporum f. sp. niveum

Genome size and chromosome number in seven geographically separated isolates representing six mitochondrial DNA (mtDNA) restriction fragment length polymorphism (RFLP) groups (RFLPG I-VI) and the three known pathological races of Fusarium oxysporum f. sp. niveum, causal agent of Fusarium wilt of watermelon, were examined by transverse alternating field electrophoresis (TAFE). Chromosome-size DNA was separated on 0.8% agarose gel at 50 or 80 V with five switch intervals for 168 h. Six karyotypes were detected among the seven isolates. Two representative isolates from mtDNA RFLPG I had two karyotypes, whereas the representative isolates from mtDNA RFLPGs IV and V had the same karyotype [...]