ISOENZYMATIC VARIABILITY OF COLLETOTRICHUM-LINDEMUTHIANUM ISOLATES WITH DIFFERENT VIRULENCE LEVEL

A methodology for extraction and isoenzyme analysis of monoconidial isolates of Colletotrichum lindemutbianum belonging to different physiological races was developed as an additional criterium to characterize races and study the genetics of the pathogen. Among the enzymes studied on starch gel electrophoresis, ALDH, ADH, ALD, ME, alpha-EST, beta-EST, ACP, PGI, HK, MDH and KADH displayed interpretable resolution and activity. Twenty-two isoenzymatic loci were detected from which 13 were polymorphic, and considered as potential markers to study the genetic variability in C. lindemuthianum. The relatively large number of phenotypic/genotypic categories reflected the occurrence of a broad heterogeneity in the sampled population. The race grouping based on isoenzyme analysis did not completely agree with those published on the basis of the response to inoculation on host plant differentials.