FAMILY MARMORACEAE 



1175 



British Queen). Immunity to aphid in- 

 fection with this virus is found in the 

 varieties Katahdin and Earlaine. A 

 combination disease, characterized by 

 pronounced yellow-mosaic patterns, is 

 caused by this virus in the variety Irish 

 Chieftain if the potato-veinbanding virus 

 {Marrnor wpsilon) is also present. In 

 tobacco, experimentally, faint veinband- 

 ing mosaic. 



Transmission: To potato, by rubbing 

 methods of inoculation of expressed juice, 

 using carborundum powder; to tobacco, 

 by rubbing without carborundum. By 

 aphids. Aphis abbreviata Patch and 

 Myzus persicae (Sulz.) (APHIDIDAE). 



Serological relationships : No cross - 

 precipitin reactions with potato aucuba- 

 mosaic virus, potato-veinbanding virus, 

 tobacco-mosaic virus, tobacco-etch virus, 

 tobacco-ringspot virus, or pea-mosaic 

 virus . 



Immunological relationships : A feeble 

 strain of this virus has been found to pro- 

 tect fully against the typical strain in the 

 Netherlands. 



Thermal inactivation : At 50° C in 10 

 minutes . 



Literature: Bawden, Ann. Appl. Biol., 

 ^3, 1936, 487-497; Chester, Phytopath., 

 25, 1935, 686-701; Dykstra, Phytopath., 

 29, 1939, 40-67; Hansen, Tidsskr. Plan- 

 teavl, 42, 1937, 631-681; Murphy and 

 Loughnane, Sci. Proc. Roy. Dublin Soc, 

 21, 1936, 419-430; Murphy and McKay, 

 ibid., 20, 1932, 227-247; Oortwijn Botjes, 

 Tijdsch. Plantenziekten, 45, 1939, 25- 

 29; Schultz ei al., Phytopath., 27, 1937, 

 190-197; SO, 1940,944-951. 



11. Maimer aucuba H. {loc. cit., 49). 

 From New Latin Aucuba, a genus of 

 plants having mottled foliage . 



Common name : Potato aucuba -mosaic 

 virus. 



Hosts: SOLAN ACE AE—Solanum tu- 

 berosum L., potato. Experimentally, also 

 Atropa belladonna L. (symptomless) ; 

 Capsicum frutescens L., pepper; Datura 

 stramonium L., Jimson weed (symptom- 

 less); Hyoscyamus niger L., henbane 



(symptomless); Lycopersicon esculentum 

 Mill., tomato; Petunia hybrida Vilm., 

 petunia (symptomless); Nicotiana ta- 

 bacum L., tobacco (symptomless) ; *Soia- 

 num dulcamara L., bittersweet ; S. nigrum 

 L. var. nodiflorum. 



Geographical distribution : United 

 States, Great Britain, Europe. 



Induced disease : In potato, yellow 

 spots on lower leaves of some varieties ; 

 in the variety Irish Chieftain, brilliant 

 yellow mottle over whole plant, perhaps 

 because of simultaneous presence of po- 

 tato mild-mosaic virus in this variety. 

 Necrosis of the cortex and of the pith in 

 tubers in many varieties. 



Transmission : By inoculation of ex- 

 pressed juice. Probably by aphid, My- 

 zus persicae (Sulz.) {APHIDIDAE). 



Serological relationships : No precipitin 

 cross -reactions with potato mild-mosaic 

 virus, potato-veinbanding virus, tobacco- 

 mosaic virus, tobacco-etch virus, tobacco- 

 ringspot virus, or pea-mosaic virus. 

 Precipitin cross-reactions with the 

 Canada-streak strain of potato aucuba- 

 mosaic virus. 



Thermal inactivation : At 65 to 68° C 

 in 10 minutes. 



Filterability : Passes Pasteur-Cham- 

 berland Li filter, but not L3 or L5. 



Literature: Chester, Phytopath., 25, 

 1935, 686-701; 27, 1937, 903-912; Clinch, 

 Sci. Proc. Roy. Dublin Soc, 22, 1941, 

 435-445; Clinch et al., ibid., 21, 1936, 431- 

 448; Dykstra, Phytopath., 29, 1939, 917- 

 933. 



Strains : One strain differing from the 

 t3'pe has been given a varietal name : 



11a. Marmor aucuba var. canadense 

 Black and Price. (Phytopath. 30, 1940, 

 444.) From common name of strain. 



Common name : Canada-streak strain of 

 potato aucuba-mosaic virus. Differing 

 from the type variety by tendency to 

 produce necrosis in stems, veins, petioles, 

 and leaves and also, about 2 months after 

 harvest, in pith of tuber, especially at 

 stem end. (Chester, Phytopath., 27, 



