FAMILY MARMORACEAE 



1205 



thurn solani Kalt. (APHIDIDAE) ; 

 virus is not transmitted by these aphids 

 to their descendants. Not through seeds 

 of beet. Virus overwinters in beets 

 stored for subsequent use in seed produc- 

 tion. 



Serological relationships: Specific pre- 

 cipitating antiserum effective with crude 

 sap of diseased, not healthy, plants and 

 with sap of diseased plants after pas- 

 sage through a Chamberland Li, not Ls, 

 filter candle; ineffective with sap from 

 beet plants suffering from mosaic. 



Thermal inaetivation: Virus heated 

 to about 52°C no longer precipitates 

 with specific antiserum. 



Literature: Kleczkowski and Watson, 

 Ann. Appl. Biol., 31, 1944, 116-120; Peth- 

 erbridge and Stirrup, London, Ministry 

 Agr. and Fisheries, Bull. 93, 1935; Quan- 

 jer and Roland, Tijdschr. Plantenziek- 

 ten, 42, 1936, 45-70; Roland, ibid., 45, 

 1939, 1-22, 181-203; Schreven, Meded. 

 Inst, voor Suikerbietenteelt, Bergen op 

 Zoom, 6, 1936, 1; Watson, Proc. Roy. 

 Soc. London, Ser. B, 128, 1940, 535-552; 

 Ann. Appl. Biol., 29, 1942, 358-365. 



3. Corium rubi H. {loc. cit., 121). 

 From New Latin Rubus, generic name of 

 raspberry, from Latin rubus, bramble 

 bush. 



Common name : Raspberry leaf -curl 

 virus. 



Host : ROSACE AE— Rubus idaeus L., 

 red raspberry. 



Insusceptible species : ROSACE AE — 

 Rubus occidentalis L., black raspberry; 

 R. neglectus Peck, purple raspberry. 



Geographical distribution : Unitetl 

 States, not in England. 



Induced disease : In red raspberry, 

 veins retarded in growth, causing down- 

 ward curling of leaf margins and crinkling 

 of leaf lamina. Foliage dark green, dry in 

 appearance, not wilting readily. In late 

 summer, leaves bronzed, leaf surface glis- 

 tening. Diseased canes easily winter- 

 killed. Berries small and poor. The 



English variety Lloyd George is intol- 

 erant of the disease and is killed. 



Transmission : By aphid. Aphis rubi- 

 cola Oestl. (== A. rubiphila Patch) 

 (APHIDIDAE). Not by inoculation 

 of expressed juice. 



Literature : Bennett, Michigan Agr. 

 Exp. Sta., Tech. Bull. 80, 1927; Phyto- 

 path., 20, 1930, 787-802, Harris, East 

 Mailing Res. Sta., Ann. Rpt. for 1934, 

 1935; Rankin, New York Agr. Exp. Sta., 

 Geneva, Tech. Bull. 175, 1931. 



Strains : A strain differing from the 

 type, var. alpha H. {loc. cit., 121), has 

 been given a varietal name derived frona 

 its common name, raspberry beta-curl 

 virus : 



3a. Corium rubi var. beta H. {loc. cit., 

 122). Infecting black and purple rasp- 

 berries, as well as the red raspberry, 

 which alone is susceptible to the type 

 strain, raspberry alpha-curl virus. (Ben- 

 nett, Phytopath., 20, 1930, 787-802.) 



4. Corium ruborum (Zeller and Braun) 

 comb. nov. (Minuor ruborum Zeller and 

 Braun, Phytopath., 33, 1943, 161.) From 

 Latin rubus, bramble bush. 



Common name : Raspberry decline-dis- 

 ease virus. 



Host : ROSACE AE — Rubus idaeus L., 

 red raspberry. 



Geographical distribution : United 

 States (Oregon). 



Induced disease : In Cuthbert rasp- 

 berry, shoots retarded in spring, reddish; 

 leaves in autumn rolled downward, fluted 

 along veins, less green than normal be- 

 tween veins, slightly bronzed along mar- 

 gins and crests between veins. Inter- 

 nodes shortened near tips of canes. Af- 

 fected canes small, weak, not hardy in 

 winter. Small roots and feeder rootlets 

 fewer than in healthy plants. Disease 

 progressive over about three years. 

 Fruits small, irregular, tending to be 

 globose, crumblj^ when ripe, worthless. 



Transmission: By grafting. No insect 

 vector is known. 



