Origin of triploid Arachis by autopolyploidy

Origin of triploid <i>Arachis</i> by autopolyploidy

The origins of the economically important tetraploids in Arachis (including peanut) have largely been studied; however, the polyploidization pathway through which they arose still remains unknown. Lavia et al. make a detailed cytogenetic analysis of the recent, spontaneously originated triploid cytotype of A. pintoi and find that this cytotype arose by autopolyploidy. The occurrence of unreduced gametes strongly supports sexual polyploidization as the most probable mechanisms involved in the origin of polyploid species of this genus.