FAMILY MARMORACEAE 



1195 



vector is known. Transmission by in- 

 oculation of expressed juice has not been 

 demonstrated. 



Thermal inactivation : Not demon- 

 strated. Virus in stem tissues with- 

 stands at least 50° C for as much as 60 

 minutes without being inactivated. 



Literature: Blodgett, Phytopath., 28, 

 1938, 937-938; Bradford and .loley, Jour., 

 Agr. Res., 46', 1933, 901-908; Christoff, 

 Phytopath. Zeitschr., 7, 1934, 521-536; S, 

 1935, 285-296; Thomas, Hilgardia, 10, 

 1937, 581-588. 



48. Marmor fragariae H. {loc. cit., 78). 

 From New Latin Fragaria, generic name 

 of strawberry, from Latin fraga, straw- 

 berries. 



Common name: Strawberry-crinkle 

 virus. 



Hosts : ROSACEAE — Fragaria hy- 

 brids, cultivated strawberries. Experi- 

 mentally, also Fragaria vesca L., wood- 

 land strawberry. 



Geographical distribution: United 

 States, England. 



Induced disease: In cultivated straw- 

 berry, crinkling and chlorosis of leaves. 

 At first, minute chlorotic flecks appear in 

 young leaves. These fiecks enlarge, and 

 small necrotic spots may appear in their 

 centers. Vein-clearing appears fre- 

 quently. Affected foliage lighter and less 

 uniformly green than normal. The vari- 

 ety Royal Sovereign may appear normal 

 through carrying this virus. 



Transmission : By aphid, Myzus fragae- 

 folii Ckll. (= Capitophoriis fragariae 

 Theob.) (APHIDIDAE). By grafting. 

 Not by inoculation of expressed juice. 



Literature: Harris, Ann. Rept. East 

 Mailing Res. Sta. for 1936, 1937, 201-211, 

 212-221; ibid., for 1937, 1938, 201-202; 

 Harris and Hildebrand, Canad. Jour. Res., 

 C, 15, 1937, 252-280; Ogilvie et al., Ann. 

 Rept. Long Ashton Res. Sta. for 1933, 

 1934,. 96-97; Vaughan, Phytopath., 23, 

 1933, 738-740; Zeller, Oregon Agr. Exp. 

 Sta., Sta. Bull. 319, 1933; Zeller and 

 \\aughan, Phytopath., 22, 1932, 709-713. 



49. Marmor marginans H. (loc. cit., 

 79). From Latin marginare, to provide 

 with a margin. 



Common name: Strawberry j^ellow- 

 edge virus. 



Hosts : ROSACEAE— Fragaria hy- 

 brids, strawberries; Fragaria calif arnica 

 C. and S. ; F . chiloensis Duch. (symptom- 

 less). Experimentally, also Fragaria 

 vesca L. ; F. virginiana Duch. (some 

 clones appear to be immune to infection 

 by runner inarching). 



Geographical distribution: United 

 States, England, France, New Zealand. 



Induced disease : In strawberry, plant 

 appears flat with outer zone of leaves more 

 or less normal, central leaves dwarfed, 

 yellow-edged, deficient in red pigmenta- 

 tion. The variety Premier may carry 

 this virus without showing any obvious 

 manifestation of disease. 



Transmission : By aphid, Myzus fragae- 

 folii Ckll. {APHIDIDAE). By graft- 

 ing. Not b}' inoculation of expressed 

 juice. Not through seeds from diseased 

 plants. 



Literature : Chamberlain, New Zealand 

 Jour. Agr., J^9, 1934, 226-231; Harris, 

 Jour. Pom. and Hort. Science, 11, 1933, 

 56-76; Harris and Hildebrand, Canad. 

 Jour. Res., C, 15, 1937, 252-280; Hilde- 

 brand, ibid., C, 19, 1941, 225-233; Plaki- 

 das, Phytopath., 16, 1926, 423-426; Jour. 

 Agr. Res., 35, 1927, 1057-1090. 



50. Marmor rubi H. (Holmes, loc. cit., 

 80; Poecile rubi McKinney, Jour. Wash- 

 ington Acad. Science, 3J^, 1944, 148.) 

 From Latin rubus, bramble bush. 



Common name : Red-raspberry mosaic 

 virus. 



Hosts : ROSACEAE — Rubus idaeus 

 L., red raspberry; R. occidentalis L., 

 black raspberry. 



Geographical distribution: United 

 States. 



Induced disease : In red raspberry, sys- 

 temic chlorotic mottling, masked at high 

 temperatures of summer. Foliage de- 

 velopment delayed in spring. In some 

 varieties, leaf petioles and cane tips die, 



