Comparison of RAPD, AFLP, and EF-1alpha Sequences for the Phylogenetic Analysis of Fusarium oxysporum and Its formae speciales in Korea

Although Fursarium oxysporum causes diseases in economically important plant hosts, identification of F. oxysporum formae speciales has been difficult due to confusing phenotypic classification systems. To resolve these complexity, we evaluated genetic relationship of nine formae speciales of F. oxysporum with random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), and translation elongation factor-1 alpha (EF-1alpha) gene. In addition, the correlation between mycotoxin content of fusaric acid and isolates based on molecular marker data was evaluated using the modified Mantel's test. According to these result, these fusaric acid-producing strains could not identify clearly, and independent of geographic locations and host specificities. However, in the identification of F. oxysporum formae speciales, especially, AFLP analysis showed a higher discriminatory power than that of a the RAPD and EF-1alpha analyses, all three techniques were able to detect genetic variability among F. oxysporum formae speciales in this study.

Neuropharmacological studies on Fusarium toxins--II: Total toxin extract from F. oxysporum.

The neuropharmacological activity profile of total fungal extract of F. oxysporum (FO) was investigated. FO enhanced spontaneous locomotor activity, exploratory behaviour and reduced pentobarbitone hypnosis. It had per se anticonvulsant action against maximal electroshock seizure (MES) and potentiated phenobarbitone and phenytoin in MES and also potentiated pentylenetetrazol (PTZ) convulsion. It antagonised morphine, tetrabenazine and haloperidol catalepsy. FO did not show per se analgesia or potentiation of morphine antinociception in mice, while both effects were present in rats. The effect of FO on body temperature was complex. It produced per se reduction in rectal temperature and potentiated the hypothermic responses of reserpine, apomorphine, PEA and I-dopa, and also the hyperthermic response of 5-HTP. The hyperthermic response of haloperidol was reversed by FO. It potentiated amphetamine and morphine lethality, amphetamine, PEA and apomorphine stereotypy, 5-HTP headtwitch response and post-swim grooming response. On swim-stress immobility, while the time of onset of immobility was reduced, FO did not modify the duration of immobility. On foot-shock induced aggression in paired rats, FO produced a decrease in the latency to onset of fighting behaviour and increased the total contact period and the cumulative aggressive score. FO potentiated clonidine automutilation. It has, thus, facilitated aggressive behaviour. The effects are likely to be due to the presence of fusaric acid in FO, which inhibits dopamine beta-hydroxylase and is known to have dopaminergic effects. This investigation has practical implications. since F. oxysporum is a common food contaminant.