1214 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



number of other solanaceous plants have 

 been reported as susceptible, but not 

 Capsicvm fruiescens L., pepper; Lyco- 

 persicon esculentvm Mill., tomato; So- 

 larium melongena L., eggplant; or S. 

 tuberosum L., potato. 



Geographical distribution : United 

 States. 



Induced disease : In tobacco, local and 

 systemic necrosis in 3 daj's, with 

 irregular spot, line, and ring-like lesions, 

 followed by recovery from necrotic mani- 

 festations of disease. Recovered leaves 

 may show a mild mottling and regularly 

 contain virus ; reinoculation does not 

 induce formation of necrotic lesions in 

 them. 



Transmission : By inoculation of ex- 

 pressed juice. Not through seeds from 

 diseased plants. 



Immunological relationships : No cross- 

 protection with respect to A. tabaci, and 

 several viruses of the mosaic group. 



Thermal inactivation : At 53° C in 10 

 minutes. 



Literature : Johnson, Phytopath., 26, 

 1936, 285-292; Trans. Wisconsin Acad. 

 Sciences, Arts and Letters, SO, 1937, 

 27-34. 



4. Annulus apertus spec. nov. From 

 Latin apertus, frank. 



Common name: Broad-ringspot virus. 



Hosts : SOLAN ACE AE—Nicotiana 

 tabacum L., tobacco. Experimentally 

 also to many species in this and other 

 families. 



Insusceptible species: CHENOPODI- 

 ACEAE—Beta vulgaris L. C UC URBI- 

 TACEAE — Ciirullus vulgaris Schrad. 

 LEGUMINOSAE—Medicago saliva L., 

 Melilotus alba Desr. 



Geographical distribution : United 

 States (Wisconsin). 



Induced disease : In tobacco, indistinct 

 yellow-spot primary lesions, becoming 

 chlorotic or necrotic rings with concen- 

 tric markings; small chlorotic rings, 

 sometimes concentric, or fine brown ne- 

 crotic rings as secondary lesions ; young 

 leaves puckered at first, somewhat mal- 

 formed. 



Transmission : By inoculation of ex- 

 pressed juice. 



Immunological relationships : Protects 

 against reinfection with homologous virus 

 but leaves host susceptible to infection 

 by Annulus tabaci, A. zonatus, and some 

 mosaic -type viruses. 



Literature : Johnson and Fulton, Phy- 

 topath., 32, 1942, 605-612. 



5. Annulus dubius (Holmes) comb.nov. 

 (Marmor dubium H., loc. cit., 42.) From 

 Latin dubius, uncertain, in reference to 

 a common name, potato virus X, often 

 used to designate this virus. 



Common name : Potato-mottle virus 

 (strains of this virus have been studied at 

 various times under the names potato 

 latent virus, potato virus X, potato- 

 anecrosis virus, virulent latent virus, 

 simple mosaic virus, healthy potato virus, 

 Hyoscyamus IV virus, President streak 

 virus, potato foliar-necrosis virus, potato 

 acronecrotic streak virus, Up-to-Date 

 streak virus, potato viruses B and D, 

 Solanum viruses 1, 4, and 6.) 



Hosts: SOLA N ACE A E— Solanum tu- 

 berosuni L., potato; Lycopersicon esculen- 

 tum Mill., tomato. Experimentally, also 

 SOLAN ACE AE — Capsicum frutescens 

 L., pepper; Datura stramonium L., Jim- 

 son weed ; Hyoscyamus niger L., henbane ; 

 Nicotiana tabacum L., tobacco; Physalis 

 alkckengi L. ; Solanum didcamara L., bit- 

 tersweet ; S. nigrum L., black nightshade. 

 AM ARAN TH ACE A E— Amaranthxis 

 retroflexus L. COM POSIT AE— Chrysan- 

 themum morifolium Ram. SCROPHU- 

 LARIACEAE — Veronica sp., common 

 speedwell. 



Geographical distribution : Widespread 

 throughout the world; present in all 

 known stocks of tubers of some potato 

 varieties in the United States. 



Induced disease : In potato, usually no 

 chlorotic mottling, sometimes a little ; 

 intracellular inclusions of the vacuolated, 

 granular type ; some varieties that are 

 virtually immune in the field owe their 

 tendency to localize the virus in necrotic 

 primary lesions or in top-necrosis of first 

 systemically infected plants to a dom- 



