1188 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



son clover; T. repens L., white clover; 

 Melilotvs alba Desr., white sweet clover; 

 Pisum sativum L., pea. 



Insusceptible species: LEGUMINO- 

 SAE — Phaseolus vulgaris L., bean; P. 

 aureus Roxb., mung bean; Medicago sali- 

 va L., alfalfa. SOLAN ACE AE—Lyco- 

 persicon esculentum Mill., tomato; Nico- 

 tiana lahacum L., tobacco; N. glutinosa 

 L.; N. langsdorffii Weinm.; A^. rustica 

 L.; N. sylvestris Spegaz. and Comes; 

 Solanum tuberosum L., potato. 



Geographical distribution : United 

 States. 



Induced disease : In red clover, yellow 

 color along veins, but no mottling. Some- 

 times small yellow spots in interveinal 

 areas. Little or no stunting. In Vicia 

 faba, experimentally, necrotic splotches 

 or rings sometimes at site of inoculation. 

 Clearing of veins followed by appear- 

 ance of whitish bands along the veins. 

 Stalks discolored, purplish. Diseased 

 plants are stunted and often die back to a 

 point near the base of the stalk, inducing 

 new growth from buds on the stem. 



Transmission : By inoculation of ex- 

 pressed juice, using carborundum. By 

 aphid, Macrosiphum pisi Kalt. (APHP 

 DIDAE), without incubation period and 

 without long retention. Not by aphids, 

 Macrosiphum solanijolii Ashm. (= M. 

 gei Koch) or Aphis rumicis Linn. 

 (APHIDIDAE). 



Thermal inactivation : At 60° C in 10 

 minutes. 



Literature: Osborn, Phytopath., 27, 

 1937, 1051-1058; Zaumeyer, Jour. Agr. 

 Res., S6, 1938; 747-772; Zaumeyer and 

 Wade, Phytopath., 27, 1937, 1009-1013. 



34. Marmor pachyrhizi spec. nov. 

 From New Latin Pachyrhizus, generic 

 name of sincamas. 



Common name : Sincamas-mosaic virus. 



Host : . LEG UM I NOSAE— Pachyrhi- 

 zus erosus (L.) Urb., sincamas (yam 

 bean). 



Insusceptible species: LEGUMINO- 

 SAE — Phaseolus vulgaris L., bean. 



Geographical distribution : Philippine 

 Islands. 



Induced disease : In sincamas, chlorotic 

 mottling of foliage; in plants infected 

 when young, dwarfing. 



Transmission: By inoculation of ex- 

 pressed juice, in the presence of sand as 

 abrasive. Through about 25 percent of 

 the seeds from infected plants. Not 

 through soil, interlacing of roots, or casual 

 contacts of leaves and stems. No insect 

 vector is known. 



Literature: Fajardo and Maranon, 

 Philippine Jour. Science, 48, 1932, 129- 

 142. 



35. Marmor vignae spec. nov. From 

 New Latin Vigna, generic name of cow- 

 pea, from family name of an Italian 

 botanist, Domenico Vigna. 



Common name : Cowpea-mosaic virus. 



Hosts : LEGUM I NOSAE— Vigna sin- 

 ensis (L.) Endl., cowpea. Experimen- 

 tally, also Phaseolus lunatus L., lima bean. 



Geographical distribution: United 

 States (Arkansas, Oklahoma, Louisiana, 

 Indiana, Georgia, Iowa, Mississippi, Kan- 

 sas, New Jersey). 



Induced disease : In cowpea, clearing of 

 veins followed by chlorotic mottling, 

 slight convex cupping of leaflets, short- 

 ened internodes, abortion of flowers, 

 twisting of petioles, delayed maturity. 

 Malformation of leaves, stunting of 

 plants, and reduction of yield more pro- 

 nounced in some varieties of cowpea than 

 in others. 



Transmission : By inoculation of ex- 

 pressed juice, especially in the presence 

 of fine carborundum powder. By aphids, 

 Macrosiphum solanifolii Ashm., M. pisi 

 Kalt., Aphis gossypii Glov. {APHIDI- 

 DAE) ; not by various beetles nor by the 

 bean leaf hopper, Empoasca fabae LeB. 

 (CICADELLIDAE). Through 5 per 

 cent of seeds from infected cowpea plants. 



Thermal inactivation: At 72 to 75° C 

 in 10 minutes. 



Other properties : Infectious in dilu- 

 tions as high as 1 :1000 and after 2 days 



