1168 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



Strains : A distinctive strain has been 

 distinguished from the type, var. chloro- 

 genus H. {loc. cit., 27), by the varietal 

 name : 



3a. Marmor astrictum var. aucuba H. 

 (loc. cit., 29). Differing from the type of 

 this species by inducing a yellow-mottl- 

 ing, rather than a green-mottling, mosaic 

 in cucumber (Ainsworth, Ann. Appl. 

 Biol., 32, 1935, 55-67). 



4. Marmor laesiofaciens Zaumeyer and 

 Harter. (Jour. Agr. Res., 67, 1943, 305.) 

 From Latin laesio, substantive from 

 laedere, to injure, and participle from 

 facere, to make. 



Common name: Bean-mosaic virus 4; 

 southern bean mosaic virus 1 . 



Hosts : LEG UMINOSAE—Phaseolus 

 vulgaris L., bean. Experimentally, also 

 Phaseolus lunatus L., sieva bean; Soja 

 max Piper var. Vii-ginia, Virginia soy 

 bean . 



Insusceptible species : All tested spe- 

 cies in families other than the LEGU- 

 MINOSAE. 



Geographical distribution: United 

 States (Louisiana). 



Induced disease : In bean, systemic 

 chlorotic mottling in some varieties, 

 localized necrosis in others; in a few 

 varieties, systemic necrosis. In mot- 

 tling-type varieties, chlorotic mottling of 

 foliage; pods marked by dark green 

 blotches or shiny areas, slightly mal- 

 formed, short, frequently curled at end. 

 In necrotic-type varieties with localized 

 response, bearing a dominant gene lacking 

 in mottling-type varieties, reddish ne- 

 crotic lesions at the site of inoculation ; no 

 evidence of systemic spread of virus. In 

 varieties showing systemic necrosis, pin- 

 point or slightly larger necrotic primary 

 lesions with veinal necrosis of inoculated 

 leaf; systemic veinal necrosis, distortion 

 and curling of affected leaves, drooping 

 at the pulvini ; stem and petiole streak ; 

 eventual death of plant . 



Transmission : By inoculation of ex- 

 pressed juice. Through seeds from in- 

 fected plants. 



Serological relationships : Not demon- 

 strated. 



Immunological relationships : Previous 

 infection with bean-mosaic virus, Marmor 

 phaseoli, does not protect against infec- 

 tion with this virus. 



Thermal inactivation : At 90 to 95° C, 

 time not stated, probably 10 minutes. 



Other properties : Withstands dilution 

 of 1 : 500,000 and aging 32 weeks at 18° C. 



Literature : Zaumeyer and Harter, Phy- 

 topath., 32, 1942, 438-439; 33, 1943, 16; 

 34, 1944, 510-512; Jour. Agr. Res., 67, 

 1943, 295-300, 305-328. 



Strains : A strain differing from the 

 type lias been given the varietal name : 



4a. Marmor laesiofaciens var. ininus 

 Zaumeyer and Harter. (Jour. Agr. Res., 

 67 , 1943, 305.) From Latin minor, lesser. 

 Differing from the type by inducing 

 formation of slightly less diffuse and 

 spreading lesions in necrotic-type bean 

 leaves; also by inducing milder early 

 symptoms and more severe late symptoms 

 in mottling-type beans. Passes through 

 seeds from infected plants to infect seed- 

 lings grown from them. Found in addi- 

 tional localities in the United States 

 (California, Colorado, Idaho, Maryland). 



5. Marmor lethale H. (loc. cit., 86). 

 From Latin lethalis, causing death. 



Common name : Tobacco-necrosis virus. 



Hosts: SOLAN ACE AE—Nicotiana 

 tabacum L., tobacco; A'', gluiinosa L.; N. 

 langsdorffii Weinm. ; Lycopersicon escu- 

 lenium Mill., tomato; Solanum nigrum 

 L. COMPOSITAE—k^iQx. GE RANI- 

 ACE AE — Pelargonium hortorum Bailey. 

 LEG UM I NOSAE— Phaseolus vulgaris 

 L., bean. Confined to roots of these 

 natural hosts except in the cases of 

 Nicotiana tabacum and N . gliitinosa in 

 which lower leaves are sometimes in- 

 vaded; necrotic lesions along midrib and 

 larger veins in these. No obvious mani" 

 festations of disease in infected roots. 

 Experimentally to plants in many fami- 

 lies with production of localized necrotic 

 lesions only. 



