FAMILY MARMORACEAE 



1173 



13. M armor cruciferarum. 



14. M armor brassicac. 



15. Marmor betae. 



16. Marmor lactucae. 



17. Marmor dahliae. 



18. Marmor phaseoli. 



19. Marmor leguminosarum. 



20. Marmor pisi. 



21. Marmor medicaginis. 

 III. Infecting monocotyledonous, but not dicotyledonous, plants. 



22. Marmor tulipae. 



23. Marmor mite. 



24. Marmor iridis. 



25. Marmor sacchari. 

 . 26. Marmor cepae. 



27. Marmor scillearum. 



9. Marmor cucumeris Holmes. 

 (Holmes, Handb. Phytopath. Viruses, 

 1939, 31; Murialba cucumeris Valleau, 

 Phytopath., 30, 1940, 823.) From Latin 

 ciicumis, cucumber. 



Common name : Cucumber-mosaic 

 virus. 



Hosts : Very wide range of hosts among 

 dicotyledonous and monocotyledonous 

 plants; cucumber, celery, spinach, to- 

 bacco, and pepper are sometimes serioush' 

 affected. Overwintering hosts are : SOL- 

 ANACEAE — Physalis subglabrata Mac- 

 kenzie and Bush, P. helerophylla Nees. 

 ASCLEPIADACEAE—Asclepias syri- 

 aca L. PHYTOLACCACEAE— Phyto- 

 lacca decandra L. LAB I AT AE — Ne- 

 peta cataria L. Probably there are also 

 other susceptible perennials. 



Geographical distribution : Probably al- 

 most world-wide. 



Induced disease : In cucumber, Cucu- 

 mis sativus L., yellowish-green systemic 

 mottling. Leaves small, distorted, 

 curled; plants dwarfed, internodes short- 

 ened. Few fruits set. Fruits mottled, 

 nusshapen, giving the disease the name 

 "white pickle." In black cowpea, Vigna 

 sinensis (L.) Endl., small reddish ne- 

 crotic local lesions only. No intracellular 

 bodies are found in plants infected with 

 cucumber-mosaic virus. 



Transmission : By inoculation of ex- 

 pressed juice. By aphids, Myzus persi- 

 cae (Sulz.), M. pseudosolani Theob., M. 



circumflexus (Buckt.), Macrosiphum sol- 

 anifolii Ashm., and Aphis gossrjpii Glov. 

 {APHIDIDAE). Through seeds of dis- 

 eased plants in Echinocystis lohata 

 (Michx.) Torr. and Gray, wild cucumber, 

 in Ciicumis melo L., muskmelon, and in 

 Cucurbita pepo L., vegetable maiTow. 

 By several species of dodder, Cusciita 

 calif ornica Choisy, C. campeslris 

 Yuncker, and C. suhinclusa Dur. and 

 Hilg. {CONVOLVULACEAE). 



Immunological relationships : Infection 

 with the type and other chlorotic -mot- 

 tling strains protects zinnia against sub- 

 sequent infection by an indicator strain 

 of this virus (var. judicis). 



Thermal inactivation : At 70 to 80'^ C 

 in 10 minutes. 



Filterability : Passes Berkefeld W and 

 N filters and collodion membranes of 45 

 millimicron average pore diameter. 



Other properties : Inactivated by dry- 

 ing or 3 to 4 days' storage in juice at room 

 temperature. 



Literature: Ainsworth, Ann. Appl. 

 Biol., 25, 1938, 867-869; Chamberlain, 

 New Zealand Jour. Science and Tech- 

 nology, 21, 1939, 73A-90A ; Celino, Philip- 

 pine Agr., 29, 1940, 379-414; Doolittle, 

 Phytopath., 6, 1916, 145-147; U. S. Dept. 

 Agr., Bull. 879, 1920; Doolittle and 

 Walker, Jour. Agr. Res., 31, 1925, 1-58; 

 Gilbert, Phytopath., 6, 1916, 143-144; 

 Hoggan, Jour. Agr. Res., 47, 1933, 689- 

 704; Jagger, Phytopath., 6, 1916, 148-151 ; 



