A POTYVIRUS ISOLATED FROM SENNA-OCCIDENTALIS

A potyvirus causing severe mosaic symptoms was isolated from Senna occ identalis (syn. Cassia occidentalis) in the Yemen Republic and Ethiopi a. It was transmitted mechanically and by Myzus persicae in a non-pers istent manner. The flexuous, rod-shaped particles had a mean length of 830 nm, and pinwheels and scrolls were observed by electron microscop y of thin sections of infected Nicotiana clevelandii leaves. Its host range was narrow with only a few legume species, Nicotiana clevelandii and N. benthamiana susceptible to experimental infection. This virus was purified from N. clevelandii and the coat protein had a molecular mass of 34.5 kDa. It reacted positively in ELISA With monoclonal antib ody 197 that is specific for potyviruses, but was not decorated by ant ibodies to any other potyvirus tested when examined by electron micros copy. The virus has been tentatively named cassia severe mosaic potyvi rus.