1156 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



Filterability : Passes Berkefeld W 

 filter. 



Other properties : Virus viable at 23 

 to 27° C less than 13 hours after extraction 

 of juice from diseased plant ; not infective 

 after drying in leaf tissues. 



Literature : Barrus and Chupp, Phyto- 

 path., 12, 1922, 123-132; Black, Am. Po- 

 tato Jour., 11, 1934, 148-152; Cornell 

 Univ. Agr. E.xp. Sta., Mem. 209, 1937, 

 1-23; Phytopath., £8, 1938, 863-874; Am. 

 Jour. Bot., 27, 1940, 386-392; Am. Potato 

 Jour., 18, 1941, 231-233; Phytopath., 33, 

 1943, 363-371; Genetics, 28, 1943, 200- 

 209; Proc. Am. Philos. Soc, 88, 1944, 

 132-144; Hansing, Cornell Univ. Agr. 

 Exp. Sta., Bull. 792, 1943; Price and 

 Black, Am. Jour. Bot., 28, 1941, 594-595; 

 Taylor, Am. Potato Jour., 15, 1938, 37-40; 

 Walker and Larson, Jour. Agr. Res., 59, 

 1939, 259-280; Wat kins. Jour. Econ. Ent., 

 32, 1939, 561-564 ; Cornell Univ. Agr. Exp. 

 Sta., Bull. 758, 1941, 1-24; Younkin, Am. 

 Potato Jour., 19, 1942, 6-11. 



Strains: Beside the type variety, 

 Aureogerms vastans var. vulyare Black 

 (Am. Jour. Bot., 27, 1940, 391), on which 

 the species is based, two distinctive 

 strains have been given varietal names : 



la. Avreogenus vastans var. agalliae 

 Black. (Am. Potato Jour., 18, 1941, 233.) 

 From New Latin Agallia, generic name of 

 vector of this strain. Common name : 

 New Jersey strain of potato yellow-dwarf 

 virus. Differing from the type especially 

 in its distinctive vector, the leafhopper, 

 Agallia consiricta Van Duzee, which is 

 incapable of transmitting the type strain, 

 and in not being transmitted by Acerata- 

 gallia sangidnolenta (Provancher), com- 

 mon vector of the type variety. Experi- 

 mentally, transmitted also by Agallia 

 quadripunctata (Provancher) ; perhaps 

 rarely by Agalliopsis novella (Say); 

 Differing but little from the type in ef- 

 fects on potato (var. Green Mountain) 

 and Nicotiana rustica but more definitely 

 in effects on crimson clover, in affected 

 plants of which a rusty-brown necrosis 



along the veins, not induced by the type 

 strain, is always present in some degree. 



lb. Aureogenus vastans var. lethale 

 Black. (Am. Jour. Bot., 27, 1940, 391.) 

 From Latin lethalis, causing death. 

 Common name : Strain B5 of potato yel- 

 low-dwarf virus . Differing from the type 

 variety especially in a tendency to induce 

 in Nicotiana rustica, experimentally, 

 brown primary lesions with necrotic gray 

 centers, systemic yellowing, extensive 

 necrosis of veins, collapse of large areas 

 of leaf, and sometimes death of the host ; 

 not known to occur in nature as a separate 

 strain, but readily isolated as a variant 

 from strains collected in nature. 



2. Aureogenus magnivena Black. 

 (Proc. Am. Philos. Soc, 88, 1944, 144.) 

 From Latin magnus, large, and vena, vein. 



Common name : Clover big-vein virus. 



Host: Experimentally, LEGUMINO- 

 SAE — Trifolium incarnatum L., crimson 

 clover. 



Insusceptible species: SOLAN A- 

 CEAE — Nicotiana rustica L., Indian to- 

 bacco; Solanum tuberosum L., potato. 



Geographical distribution : United 

 States (presumably, Washington, D. C). 



Induced disease : In crimson clover, 

 experimentally, unevenly thickened 

 veins which are depressed below the up- 

 per surface of the leaf; these enlarged 

 veins, best observed from below, some- 

 times bear enations that arise from their 

 lower surfaces, leaves often curl upward 

 and inward marginally; in summer, yel- 

 lowing of leaves progresses from margins 

 inward, the yellow color being later re- 

 placed in part by red or purple red ; 

 petioles undulating; plants dwarfed; 

 internodes shortened; no clearing of 

 veins; no rusty-brown necrosis. 



Transmission: Not by inoculation of 

 expressed juice. By leafhoppers, Agal- 

 liopsis novella (Say), Agallia constricta 

 Van Duzee, A. quadripunctata (Provan- 

 cher) ; not by Aceratagallia sangnino- 

 lenia (Provancher) (CICADELLIDAE). 



