Final diagnosis


Potato spindle tuber viroid (PSTVd)

Upright and deformed foliage on a potato plant infected by <b><i>Potato Spindle Tuber Viroid</i></b> (PSTVd)
Yellowing of the upper leaves of a potato plant. <b><i>Potato Spindle Tuber Viroid</i></b> (PSTVd)
Severe leaflet deformation on tomato caused by a virulent strain of <b><i>Potato Spindle Tuber Viroid</i></b> (PSTVd)
Elongated, pear-shaped and knobbly potato tubers from a plant infected by <b><i>Potato Spindle Tuber Viroid</i></b> (PSTVd) (healthy tubers on the left).