The virus is transmitted through infected seed, mechanically and by wheat curl mite. The curl mite is invisible to the naked eye. This virus is found in all wheat growing regions of Australia.
Symptoms on leaves could be seen as light green streaks parallel to the veins. The streaks develop into blotches and form a pattern of yellow and green mosaic, (Figure 10.20). Infection at early stage can cause heads developing no seed or shrivelled grain and stunting. Mite symptoms in plants could coincide with virus symptoms, showing rolling of leaves from margins to inwards, (Figures 10.21 - 10.23).
Figure 10.20 Yellow and green streak symptoms of WSMV in wheat WSMV in wheat
Figure 10.21 Wheat curl mite feeding symptoms in wheat, showing curled and rolled leaves
Figure 10.22 Wheat curl mites feeding on wheat leaf. Mites found by uncurling affected leaves
Figure 10.23 Wheat curl mite ( Aceria tosichella )
BARLEY YELLOW DWARF VIRUS (BYDV)