Isozyme evidence of the parental origin and possible fertility of the hybrid Potamogeton×fluitans Roth

 The hybrid Potamogeton×fluitans Roth is thought to have resulted from hybridization between P. lucens L. and P. natans L. This hybrid has only been recorded at a few locations in the British Isles. At most of these sites the number of individuals found have been quite low. The one exception to this being a population in the Moors River, Dorset and South Hampshire, England, where a substantially larger population exists. Using seven different enzyme systems, this study provided support for the putative parental origin of this hybrid. In addition, the population in the Moors River was shown to contain numerous multi-locus phenotypes suggesting that these individuals may be partially fertile and may backcross to one of its parental species, or alternatively undergo selfing or crossing to produce an F₂ generation. Received December 1, 2000 Accepted June 20, 2001