Abstract :
Genetic variation among isolates of F. oxysporum f.sp. cubense (Foe)
was analysed using a DNA amplification fingerprinting (DAF) system
modified to improve reproducibility and transportability. This analysis
was done after determining the widest tolerance range (or ʹwindow of
reproducibilityʹ) for each component in amplification reaction. Reproducible
polymerase chain reaetions (PCRs) were achieved with between
25 and 250 ng of template DNA, 9-15 ^M primer, 4-6 m,M MgCl, and
2-4 units of Stoffel Fragment enzyme. For experimental work we used
the middle value of these ranges whieh allowed at least 20% error
tolerance for eaeh component. Similarly, thermoeycHng and eleetrophoresis
eonditions were also improved. Manual scoring of the DNA
fingerprints was compared to analysis of scanned gel images using the
Gel Compar program (Applied Maths, Kortrijk, Belgium). The data
were clustered by unweighted pair group method analysis (UPGMA)
based on the Jaccard similarity coefficient. Isolates of Foe representin.g
all known vegetative compatibility groups (VCGs) were examined and
the genetic relationships between the VCGs were determined. Isolates
of Foe were divided into two major groups with 30% genetic similarity.
These optimized DNA amplification, thermocycling, and electrophoresis
conditions were suitable for analysis of other organisms
and should be applicable to other techniques that use arbitrary primers
such as random amplified polymorphic DNA (RAPD) and arbitrarily
primed-PCR (AP-PCR).
Zusammenfassung
Ein robustes DNA amplification Siigerprinting-Systein zur Analyse der
genetischen Variation bei Fusarium oxysporam f,sp, cubeitse
Die genetische Variation bei Isolaten
