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

A total of 247 physiological and biochemical characters were assessed for t he differentiation of 73 strains of Colletotrichum isolated from diseased s trawberry 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 diff erential. The strains were grouped according to these differential characte rs by numerical analysis with Gower's general similarity coefficient and UP GMA average linkage clustering. The resulting dendrogram placed the strains in two major clusters. These groupings were confirmed by principal coordin ates analysis based on the average distance measure. The ordination showed that few physiological or biochemical tests were discriminatory in isolatio n, in terms of separating the major clusters. However, strain groupings obt ained by these methods strongly reflected previous rDNA and mtDNA molecular classifications.