Biological Properties of Potyvirus Isolates from Hot Pepper (Capsicum annuum L.) from the Major Growing Areas of Ethiopia

Abstract

Potyviruses cause major diseases on hot pepper (Capsicum annuum L.) in Ethiopia.Two selected isolates: 374/94 from Bako and 430/94 from Zwai were biologically characterised and compared with reference strains of other potyviruses: Ethiopian pepper mottle virus PN1 (EPMV-PN1), chilli veinal mottle virus 1037 (CVMV-1037) and pepper veinal mottle virus (PVMV). Among the 29 plant species mechanically inoculated, only 18 solanaceous hosts were infected with at least one isolate. Systemic symptoms were usually observed 10-14 days after inoculations, while local lesions appeared in 3-4 days on few hosts. Differences in the type of species infected and
symptoms produced were observed between the Ethiopian isolates. However, some degree of relationships were revealed between isolate 374/94 and PVMV on the one hand and 430/94 and EPMV-PN1 on the other. These relationships were further confirmed by the reactions of pepper and tomato breeding lines and a set of international pepper cultivars to the isolates and the reference strains. Furthermore, the isolates 374/94 and 430/94 had capsid proteins similar in size with PVMV (34.5 kDa) and EPMV-PN1 (33.5 kDa), respectively, as determined by both sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and electro-blot
immunoassay (EBIA).