THE NATURAL OCCURRENCE OF TURNIP MOSAIC POTYVIRUS IN ALLIUM-AMPELOPRASUM

An isolate of turnip mosaic potyvirus (TuMV) was obtained from Allium ampeloprasum grown in commercial greenhouses in Israel. Symptoms on in fected plants include systemic chlorosis and yellow stripes, accompani ed by growth reduction. Leaves were distorted, often showing necrotic flecking. The virus was readily transmitted mechanically, and in a non -persistent manner by aphids, among Allium, Chenopodium, Gomphrena and some Nicotiana spp. Purified preparations contained numerous filament ous particles similar to those observed in crude extracts of infected leaves. Particles from crude plant extracts had a normal length of 806 nm. Cells of infected plants contained cylindrical cytoplasmic inclus ions with pinwheel, scrolls and laminated aggregates which indicated t he presence of a potyvirus of Edwardson's subgroup III, and which rese mble those of turnip mosaic virus (TuMV). The virus reacted strongly w ith antiserum to typical isolates of TuMV in immunoelectron microscopy and western blotting but not with antisera to several other potyvirus es. Based on serological reactivity, electron microscopy, aphid transm ission and cytopathology, the virus was identified as an isolate of Tu MV.