1224 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



infective thrips. Probabl}' not through 

 seeds of infected plants. Not through 

 soil. 



Immunological relationships: Infects 

 tobacco plants previously infected with 

 tobacco-mosaic, potato-mottle, tobacco- 

 ringspot, and tomato-ringspot viruses. 



Thermal inactivation : At 42° C in 10 

 minutes. 



Filterability : Passes Gradocol mem- 

 brane of 0.45 micron pore diameter. 



Other properties : Virus readily inacti- 

 vated by desiccation or by action of oxi- 

 dizing agents ; activity prolonged by pres- 

 ence of sodium sulfite, cystein, or by low 

 temperatures. Unstable at pH values 

 below 6 and above 9. 



Literature: Ainsworth et al., Ann. 

 Appl. Biol., 21, 1934, 566-580; Andrewar- 

 tha, Trans. Roy. Soc. of So. Australia, 61, 

 1937, 163-165; Bald and Samuel, ibid., 21, 

 1934, 179-190; Berkeley, Scientific Agr., 

 15, 1935, 387-392; Best, Austral. Chem. 

 Inst. Jour, and Proc, 4, 1937, 375-392; 

 Best and Samuel, Ann. Appl. Biol., 23, 

 1936, 509-537; 759-780; Carter, Phyto- 

 path., 29, 1939, 285-287; Lewcock, 

 Queensland Agr. Jour., 4S, 1937, 665-672; 

 Linford, ibid., 22, 1932, 301-324; Magee, 

 Agr. Gaz. of New South Wales, ^7, 1936, 

 99-100, 118; McWhorter and Milbrath, 

 Phytopath., 25, 1935, 897-898 (Abst.); 

 Oregon Agr. Exp. Sta., Circ. 128, 1938; 

 Milbrath, Phytopath., 29, 1939, 156-168; 

 Moore, Nature, H7, 1941, 480-481 ; Moore 

 and Anderssen, Union of So. Africa, Dept. 

 Agr., Science Bull. 182, 1939; Parris, 

 Phytopath., 30, 1940, 299-312; Rawlins 

 and Tompkins, ibid., 26, 1936, 578-587; 

 Sakimura, ibid., 30, 1940, 281-299; Sam- 

 uel and Bald, Ann. Appl. Biol., 20, 1933, 

 70-99; Jour. Agr. So. Australia, 37, 1933, 



190-195; Samuel et al., Counc. Scient. 

 Indus. Res., Austral., Bull. 44, 1930; 

 Ann. Appl. Biol., 22, 1935, 508-524; 

 Shapovalov, Phytopath., 24, 1934, 1149 

 (Abst.); Smith, Nature, 127, 1931, 852- 

 853; Ann. Appl. Biol., 19, 1932, 305-330; 

 Jour. Minist. Agr., 39, 1933, 1097-1104; 

 Jour. Roy. Hort. Soc, 60, 1935, 304-310; 

 Snyder and Thomas, Hilgardia, 10, 1936, 

 257-262 ; Takahashi and Rawlins, Phyto- 

 path., 24, 1934, 1111-1115; Taylor and 

 Chamberlain, New Zealand Jour. Agr., 

 54, 1937, 278-283; Whipple, Phytopath., 

 26, 1936, 918-920. 



Strains : A strain differing somewhat 

 from the type, var. typicum H. {loc. cit., 

 136), has been described as damaging 

 tomatoes in the northwestern United 

 States. It has been given a distinctive 

 varietal name : 



la. Lelhum aiistraliensc var. lethale H. 

 (loc. cit., 138). From Latin lethalis, 

 deadly. Common names : Tip-blight 

 strain of tomato spotted-wilt virus, 

 Oregon tip-blight virus, tomato die-back 

 streak virus, tomato tip-blight virus. 

 Differs from the type in causing necrotic 

 leaf spotting, stem streaking, and tip 

 blighting in most hosts, without mottling 

 or bronzing of foliage ; yet in Tropaeolurn 

 inajiis L., there is little necrosis. In 

 tomato, systemic necrosis, terminal 

 shoots blighted and blackened; dead tips 

 stand upright above living foliage. 

 Fruits rough and pitted, with internal 

 pockets of necrotic tissue or with sub- 

 epidermal necrosis, appearing externally 

 as concentric brown bands. (McWhorter 

 and Milbrath, Oregon Agr. Exp. Sta., 

 Circ. 128, 1938; Milbrath, Phytopath., 

 29, 1939, 156-168.) 



