121G 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



anisotropyof flow. Destroyed by drying. 

 Inactivated bj' papaine and cyanide, but 

 by neither separately. Digested by 0.02 

 per cent solution of pepsin in 3 hours at 

 pH 4, at 38° C. Digested also by trypsin. 

 About 6 per cent of the purified virus is 

 reported to be a pentose nucleic acid, but 

 the carbohydrate to phosphorus ratio is 

 about twice that for yeast nucleic acid. 

 Guanine and pentose present. Analysis 

 of sedimented virus, carbon 47.7 to 49.5 

 per cent, hydrogen 6.8 to 7.7 per cent, 

 nitrogen 14.6 to 17.0 per cent, phosphorus 

 0.4 to 0.7 per cent, sulfur 1.1 per cent, 

 carbohydrate 2.5 to 4.3 per cent, ash 2.0 

 to 2.5 per cent. Reduction of carbo- 

 hydrate content of sample to 2.5 per cent 

 does not reduce activity of virus ; further 

 reduction inactivates. (Ainsworth, 

 Ann. Appl. Biol., 21, 1934, 581-587; 

 Bawden, Brit. Jour. Exp. Path., 16, 1935, 

 435-443; Bawden and Pirie, ibid., 19, 

 1938, 66-82; Birkeland, Bot. Gaz., 95, 

 1934, 419-436; Chester, Phytopath., S6, 

 1936, 778-785; Johnson, Wisconsin Agr. 

 Exp. Sta., Res. Bull. 76, 1927; Loring, 

 Jour. Biol. Chem., 126, 1938, 455-478; 

 Loring and Wyckoff, ibid., 121, 1937, 

 225-230.) 



5b. Annulns diibius vay . flavus Yl. {loc. 

 cit., 46). From Latin flavus, yellow. 



Common name : Yellow-mottle strain 

 of potato-mottle virus. Differing from 

 the type by imparting a yellow cast to 

 foliage of infected potatoes. (Putnam, 

 Canad. Jour. Res., Sec. C, 15, 1937, 87- 

 107.) 



5c. Annulus dubiiis var. obsciirus H. 

 (loc. cit., 46). From Latin obscurus, ob- 

 scure. Common name : Masked-mottle 

 strain of potato-mottle virus. Differing 

 from the type by systemically infecting 

 potato, tobacco, and Jimson weed with- 

 out symptoms under ordinary experi- 

 mental conditions; in pepper, however, 

 systemic necrosis is induced, as by all 

 known strains. (Chester, Phytopath., 

 26, 1936, 778-785.) 



6. Annulus delphinii spec. nov. From 

 New Latin Delphinium, generic name of 

 host . 



Common names : Delphinium-ringspot 

 virus, perennial -delphinium ringspot 

 virus. 



Hosts: RAN UNCULACEAE— Del- 

 phinium sp., perennial delphiniums. 

 Experimentally, also to CHENOPODI- 

 ACEAE—Beta vulgaris L. CUCUR- 

 BIT ACEAE — Cucumis sativus L., cu- 

 cumber. MALVACEAE — Gossypium 

 hirsutum L. RANUNC UL ACEAE— 

 Ranunculus asiaticus L. (symptomless 

 carrier). SOL AN ACEAE— Datura 



stramonium L., Nicotiana alata Link and 

 Otto, N . gluiinosa L., N. rustica L., N. 

 tabacum L., Petunia hybrida Vilm. 



Geographical distribution: United 

 States (California). 



Induced disease : In perennial del- 

 phiniums, faint chlorotic rings with 

 green or yellow centers on young leaves ; 

 irregular chlorotic spots, yellow bands, 

 or irregular chlorotic rings on mature 

 leaves. 



Transmission : By inoculation of ex- 

 pressed juice in the presence of finely 

 powdered carborundum. 



Thermal inactivation : At 65° C in 10 

 minutes. 



Literature : Severin and Dickson, Hil- 

 gardia, 14, 1942, 465-490. 



7. Annulus bergerac H. (loc. cit., 102). 

 From Bergerac, a town in southwest 

 France. 



Common name : Bergerac-ringspot 

 virus. 



Hosts : SOLAN ACEAE— Nicotiana 

 tabacum L., tobacco. Experimentally, 

 this virus has been transferred to several 

 other solanaceous plants and to Phaseolus 

 vulgaris L., bean, in the family LEGUM- 

 INOSAE. 



Geographical distribution: France. 



Induced disease : In tobacco, thin 

 necrotic -ring primary lesions, followed by 



