A physiological and biochemical approach to the systematics of Colletotrichum species pathogenic to strawberry

A total of 247 physiological and biochem- ical characters were assessed for the differentiation of 73 strains of Colletotrichum isolated from diseased strawberry plants with anthracnose symptoms. The strains had previously been grouped using data from a range of DNA analyses. Approximately 41% of the characters surveyed (i.e., 101/247) gave results that were in some way differential. The strains were grouped according to these differential characters by numerical analysis with Gower's general similarity co- efficient and UPGMA average linkage clustering. The resulting dendrogram placed the strains in two major clusters. These groupings were confirmed by princi- pal coordinates analysis based on the average dis- tance measure. The ordination showed that few phys- iological or biochemical tests were discriminatory in isolation, in terms of separating the major clusters. However, strain groupings obtained by these meth- ods strongly reflected previous rDNA and mtDNA molecular classifications.