-22- 



and Purcifull (1982). It also reacted specifically with CMV 

 antiserum in the undecorated immunosorbent electron microscopy 

 test. This virus was mechanically transmitted to cucumber, 

 tomato, N^ benthamiana , N. x edwardsonii , N. glutinosa , N. 

 tabacum Xanthi nc. , cowpea , and V^ radiata . It caused systemic 

 infection in the first six hosts and brown-colored lesions in 

 the inoculated leaves of the last two hosts. 

 Bean Yellow Mosaic Virus 



Cytoplasmic inclusions (Fig. 19), typical of potyviruses 

 and stable in 5% Triton X-100, were not frequently found in 

 epidermal and mesophyll tissues of Masdevallia stained in 0/G. 

 These inclusions, which are proteinaceous and do not contain 

 nucleic acid, failed to stain with Azure A, as would be 

 expected (Christie and Edwardson, 1977). Thin sections 

 revealed subdivision II cylindrical inclusions (Fig. 21) as 

 described previously for this virus (Edwardson, 1974). Dense 

 bodies such as those described for bean yellow mosaic virus 

 (Zettler and Abo El-Nil, 1977) were rarely found in these 

 sections. Cytoplasmic inclusions were readily detected in the 

 epidermal strips of N^ benthamiana , 'Alaska ' and 'Ranger ' peas 

 (Fig. 20). In thin sections of these tissues, numerous dense 

 bodies and cylindrical inclusions (Fig. 22), which are 

 characteristic ofbean yellow mosaic virus (Edwardson, 1974), 

 were seen. 'Little Marvel' pea plants did not become infected. 

 This is consistent with the reported insusceptibility of this 

 cultivar to BYMV (Zettler and Abo El-Nil, 1977). 



