Induction of male flowers in a pistillate line ofRicinus communis L. by silver and cobalt ions.

Aqueous solutions of silver nitrate (10-100 μg/plant) and cobalt chloride (125-500 μg/plant), injected into the main stem of plants of the pistillate cv. 240 ofRicinus communis when the vegetative shoot apex was beginning to become reproductive, induced the formation of staminate (male) flowers with viable pollen in the normally strictly pistillate (female) terminal inflorescence, their number increasing with the dose of Ag(+) and Co(2+). No formation of bisexual flowers was noted. Female flowers pollinated with pollen from the induced male ones produced fruits and viable seeds.