STREPTOMYCES SPECIES ISOLATED FROM POTATO SCABS IN FRANCE - NUMERICAL-ANALYSIS OF BIOTYPE-100 CARBON SOURCE ASSIMILATION DATA

Thirty one strains of Streptomyces isolated from common and netted sca bs in France were characterized using ''Biotype-100'' strips and 14 co nventional tests. Numerical analysis showed that S. scabiei was the si ngle causal agent of common scab in France. However the strains cluste red among S. scabiei were phenotypically heteregeneous, since 3 subphe nons were delineated. The strains clustered in subphenons la and Ic an d one strain of subphenon Ib were associated with common scab. On the other hand, a group of strains clustered in phenon 2, distinct from S. scabiei, S. acidiscabies and S. caviscabies, was often associated wit h symptoms of netted scab. None of the French strains thus far pathoge nic to potato belonged to the already described species S. acidiscabie s and S. caviscabies from Japan and North America. Phenotypic characte ristics clearly differentiated all the various groups of strains descr ibed.