A. Gelatin liquefied. 1. White colonies. 1. Erwinia amylovora. 2. Yellow colonies. a. Coagulate milk. b. H3'drol3'zes starch. 2. Erwinia vitivora. bb. Does not hydrolyze starch. 3. Erwinia milletiae. aa. Does not coagulate milk. 4. Erwinia cassavae. B. Gelatin not liquefied. 1. Luxuriant growth. 5. Erwinia salicis. 2. Verj' slight growth. 6. Erwinia tracheiphila. II.* Pathogens that normalh' cause soft rots in plants (belong in the genus Pectobacterium Waldee) . A. Gas produced in sugar media. 1. Gelatin liquefied, a. Coagulates milk. aa. Does not coagulate milk. 2. Gelatin not liquefied, a. Hydrolyzes starch. 7. Erioinia chrysanthemi. 8. Erwinia carnegieana. 9. Erwinia dissolvens. aa. Does not h.ydrolyze starch. 10. Erwinia nimipressuralis. B. Gas usually produced in sugar media, but certain isolates are non-aerogenic. 1. Growth with ethanol, dulcitol, malonate or hippurate. 11. Erwinia carotovora. 2. No growth with ethanol, dulcitol, malonate or hippurate. 12. Erwinia atroseptica. C. Gas not produced in sugar media. 1. Gelatin liquefied. a. Hydrolyzes starch. 13. Erwinia ananas. aa. Do not hydrolj^ze starch. b. White colonies. 14. Erwinia aroideae. bb. Yellow colonies. c. Grows in Uschinsky's solution. 15. Erwinia citrimaculans .
- The second group of species usually causes soft rots but includes a few not very typical
species. Waldee {loc. cit.) has proposed that the species that cause t.ypical soft rot be placed in a new genus, Pectobacterium, with Pectobacterium carotovorum as the type species. The new genus is retained in the family Enierobacteriaceae. Waldee would place the atypical species in other genera, Erwinia dissolvens for example being placed in the genus Aerobacter. As further comparative studies are needed before such changes can be made with confi- dence, the older arrangement is allowed to stand in this edition of the Manual.
