Chloroplast evidence for the multiple origins of the hybrid Potamogeton x sudermanicus Hagstr.

A previous study of the sole British population of Potamogeton x sudermanicus Hagstr. supported the putative origin of this taxon as a result of hybridization between Potamogeton acutifolius Link and Potamogeton berchtoldii Fieber. In this study, the TrnL (UAA) chloroplast region was used to identify the maternal parent of this hybrid. It was found that the two multi-enzyme phenotypes identified in previous studies had different chloroplast sequences. These sequences were shown to correspond to those of the two parental species. This is further evidence that this population is the result of at least two hybridization events and that the plants attributed to this hybrid are not an aneuploid of either of the parental species.