FAMILY RHIZOBIACEAE 227 



Acid from glucose, galactose, mannose Note : See Monograph on Root Nodule 



and sucrose. Bacteria and Leguminous Plants by E. 



Aerobic. B. Fred, I. L. Baldwin and Elizabeth 



Optimum temperature 2o°C. McCoy, University of Wisconsin Studies 



Source : Root nodules of Melilotus in Science, Madison, No. 5, 1932, xx + 



(sweet clover), Medicago, and Trigonella. 343 pp. for a more complete discussion of 



Habitat : Widelj' distributed in soils this group with an extensive bibliogra- 



in which these legumes grow. phy. 



Genus II. Agrobacterium Conn.* 



(.Jour. Bact., 44, 1942, 359.) From Greek, agrus, a field; M.L., bacterium, a small 



rod. 



Small, short rods which are typically motile with 1 to 4 peritrichous flagella (if 

 only one flagellum, lateral attachment is as common as polar). Ordinarily Gram- 

 negative. On ordinary culture media, they do not produce visible gas nor sufficient 

 acid to be detectable by litmus. In synthetic media, enough CO2 may be produced to 

 show acid with brom thymol blue, or sometimes with brom cresol purple. Gelatin 

 is either very slowly liquefied or not at all. Free nitrogen cannot be fixed ; but other 

 inorganic forms of nitrogen (nitrates or ammonium salts) can ordinarilj^ be utilized. 

 Optimum temperature, 25° to 30°C. Habitat: Soil, or plant roots in the soil; or the 

 stems of plants where they produce hypertrophies. 



The type species is Agrobacteriitm tumefaciens (Smith and Townsend) Conn. 



Key to the species of genus Agrobacterium. 



I. Plant pathogens. Produce browning of mannitol-calcium-glycerophosphate agar. 

 Nitrate reduction weak or none. 



A. Nitrite produced from nitrate toaslight extent. Galls produced on plant roots. 



1. Agrobacterium tumefaciens. 



B. Nitrite not produced from nitrate. 



1. Pathogenic to apples. 



2. Agrobacteriitm rhizogenes. 



2. Pathogenic to raspberries and blackberries. 



3. Agrobacterium rubi. 



II. Not pathogenic to plants. Produces browning in mannitol-calcium-glycerophos- 

 phate agar. Nitrate reduction vigorous, with disappearance of the nitrate. 



4. Agrobacterium radiobacier. 



1. Agrobacterium tumefaciens (Smith 1923, 189; Conn, Jour. Bact., 44, 1942, 



and Town.send) Conn. (Bacterium tume- 359.) From Latin tumefaciens, swell- 



faciens Erw. Smith and Townsend, Sci- ing up, producing a tumor, 



ence, N. S. 25, 1907, 672; Pseudomonas Probable sj'nonyms : Bacillus ampelop- 



tumefaciens Stevens, The Fungi which sorae Trevisan, in Saccardo, S3dloge 



Cause Plant Disease, 1913, 35; Bacillus Fungorum, 8, 1889, 983; Bacillus am- 



tumefaciens Holland, Jour. Bact., 5, 1920, pelopsorae Trevisan emend. Cavara, Staz. 



220; not Bacillus tumefaciens Wilson, Sperim. Agara. Ital. Modena, 30, 1897, 



Lancet, 1, 1919, 675; Phytomonas tume- 483; see Elliott, Bact. Plant Pathogens, 



faciens Bergey et al.. Manual, 1st ed., 1930, 235. 



* Prepared by Prof. H. J. Conn, New York State Experiment Station, Geneva, 

 New York, September, 1943. 



