Bacterial Diseases of Dry Edible Beans in the Central High Plains

Fig. 23. (A) Young wilt pathogen cultures exhibiting purple (top) and yellow (bottom) color variants. Note purple pigments diffusing into media. (Photo courtesy P. Lambrecht). (B) Aged culture showing remnants of purple pigments in media. Note also well defined yellow color variant colonies.



Image from Plant Health Progress article:
Bacterial Diseases of Dry Edible Beans in the Central High Plains