Biology: Concepts and Investigations 2nd Edition by Mariëlle Hoefnagels

Exercise 28

Some viroids (infectious RNA molecules that cause diseases in plants) move to new plant hosts in pollen. Which of the four main groups of plants could "catch" viroids in this way? How could you test the hypothesis that a particular viroid spreads in pollen and not via an insect vector or direct plant-to-plant contact?