IDENTIFICATION AND GENETIC VARIATION OF FUSARIUM SPECIES IN ISFAHAN, IRAN, UNING PECTIC ZYMOGRAM TECHNIQUE

The genus Fusarium is a species rich genus. Different media are required to study the
morphological characters and classify different species, a time consuming technique. In this study pectic
zymograms were used to identify species and form species of Fusarium isolates. Fusarium isolates (318) were
obtained from different areas and hosts in Isfahan Province, Iran. Isolates were identified to species based on
morphological characters. A pectic enzyme solution was prepared for each isolate using liquid media
containing citrus pectin as the sole carbon source. Electrophoresis was performed using acrylamide gel
containing 0.2% citrus pectin as the enzyme substrate. The gels were incubated in 0.1M malic acid before
staining overnight in 0.02% ruthenium red, to visualize enzyme electrophoretic patterns. Several zymogram
phenotypes were obtained for polygalacturonase and pectin esterase. In total, 12 zymogram patterns were
determined for the 318 isolates tested. The results showed that there is considerable intraspecific variation in
Fusarium species. There were 3, 5 and 2 zymogram electrophoretic patterns for Fusarium oxysporum, F.
solani and F. culmorum respectively. However, there was only one zymogram pattern for F. subglutinans and
also one for F. equiseti. Although the intraspecific variation based on pectic zymograms was not correlated to
the form species of Fusarium, species of Fusarium could be distinguished using this technique as there was
no common zymogram pattern among species.