FAMILY ]VL\RMORACEAE 



1179 



Filterability : Fails to pass Li Pasteur- 

 Chamberland filter. 



Literature: Ainsworth and Ogilvie, 

 Ann. Appl. Biol., 26, 1939, 279-297; Jag- 

 ger, Jour. Agr. Res., 20, 1921, 737-740; 

 Newhall, Phytopath., 13, 1923, 104-106. 



17. Marmor dahliae H. (loc. cit., 85). 

 From Xew Latin Dahlia, generic name of 

 host plant. 



Common name : Dahlia-mosaic virus. 



Hosts: COMPOSITAE— Dahlia pin- 

 nata Cav., dahlia. Experimentally, also 

 D. imperialis Roezl. ; D. maxonii Safford. 



Geographical distribution: L'nited 

 States, Holland, Germany, England. 



Induced disease : In intolerant varieties 

 of dahlia, chlorotic mottling of foliage, 

 leaf distortion, dwarfing of all stems and 

 of roots, occasionalh^ necrotic streaking of 

 midveins. In tolerant varieties, incon- 

 spicuous chlorotic mottling or masked 

 symptoms . 



Transmission : Bj- aphid, Myzus persi- 

 cae (Sulz.) (APHIDIDAE). By graft- 

 ing. Not by inoculation of expressed 

 juice. Not through soil. Not through 

 seeds from diseased plants. 



Literature: Brierley, Am. Dahlia Soc. 

 Bull., Ser. 9, No. 65, 1933; Contrib. Boyce 

 Thompson Inst., 5, 1933, 23.5-288; Gold- 

 stein, Bull. Torrey Bot. Club, 54, 1927, 

 285-293. 



18. Marmor phaseoli H. {loc. cit., 87). 

 From New Latin Phaseolus, generic name 

 of bean. 



Common name : Bean-mosaic virus. 



Hosts : LEGUM I NOSAE— Phaseolus 

 vulgaris L., bean. Experimentally, also 

 Phaseolus acutifolius Gray var. latifolius 

 Freem.; P. aureus Roxb.; P. calcaratus 

 Roxb.; P. lunatus L.; Lespedeza striata 

 (Thunb.) Hook, and Arn. ; Viciafaba L. ; 

 V. sativa L., spring vetch. 



Insusceptible species: LEGUM I NO- 

 SAE — Pisuni sativum L., garden pea; 

 Lathyrus odoratus L., sweet pea. 



Geographical distribution : World-wide, 

 wherever beans are grown . 



Induced disease : In bean, first leaves 



to be affected are crinkled, stiff, chloro- 

 tic; later leaves show chlorotic mottling; 

 leaf margins often rolled down. Opti- 

 mum temperature for expression of dis- 

 ease, 20 to 28° C, partial masking at 28 to 

 32° C, complete masking at 12 to 18° C. 



Transmission : By inoculation of ex- 

 pressed juice in dilutions to 1 :1000, using 

 carborundum or other abrasive powder. 

 By aphids, Aphis rumicis Linn., Macro- 

 siphum (= Illinoia) solanifolii Ashm., 

 M. pisi Kalt., Aphis gossypii Glov., A. 

 medicaginis Koch, A. spiraecola, Brevi- 

 coryne brassicae (Linn.), Hyalopterus 

 atriplicis Linn., Macrosiphum ambrosias 

 Thos., Rhopalosiphum pseudobrassicae 

 Davis, and Myzus persicae (Sulz.) 

 (APHIDIDAE). In beans, there is 

 seed transmission to 30 to 50 per cent of 

 plants grown from infected parents ; 

 pollen from infected plants is said to 

 transmit virus. 



Thermal inactivation : At 56 to 58° C in 

 10 minutes. 



Literature: Fajardo, Phytopath., 20, 



1930, 469-494, 883-888; Murphy, ibid., 

 SO, 1940, 779-784; Murphy and Pierce, 

 ibid., 28, 1938, 270-273; Parker, Jour. 

 Agr. Res., 52, 1936, 895-915; Pierce, Phy- 

 topath., 24, 1934, 87-115; , Jour. Agr. Res., 

 49, 1934, 183-188; 51, 1935, 1017-1039; 

 Reddick, II Congr. Intern. Path. Comp., 



1931, 363-366; Reddick and Stewart, 

 Phytopath., 8, 1918, 530-534; Richards 

 and Burkholder, Phytopath., 33, 1943, 

 1215-1216; Wade and Andrus, Jour. Agr. 

 Res., 63, 1941, 389-393; Wade and Zau- 

 meyer, U. S. Dept. Agr., Circ. 500, 1938; 

 Walker and Jolivette, Phytopath., 33, 

 1943, 778-788; Zaumeyer and Kearns, 

 ibid., 26, 1936, 614-629; Zaumeyer and 

 Wade, Jour. Agr. Res., 51, 1935, 715-749. 



19. Marmor leguminosarum H. {loc. 

 cit., 89). From New Latin Leguminosae , 

 family name of pea. 



Common name: Pea-mosaic virus. 



Hosts : LEG UM I NOSAE— Lathyrus 

 odoratus L., sweet pea; Pisum. sativum 

 L., pea ; Trifolium pratense L., red clover ; 

 Viciafaba L., broad bean. Experiment- 



