Morphological and molecular confirmation of the hybrid Potamogeton × salicifolius (P. lucens × P. perfoliatus, Potamogetonaceae) in Upper Volga region (Russia)

Abstract

The hybrid Potamogeton × salicifolius Wolfg. (P. lucens L. × P. perfoliatus L.) is confirmed in Russia by morphology and nrDNA polymorphism. All analyzed hybrid plants had monomorphic nrDNA ITS fragments. In the studied river P. × salicifolius with intermediate characters grows in more or less flowing water, whereas the hybrid with P. lucens-like morphotype occurs in practically stagnant water. Some range of phenotypic variability in P. × salicifolius is caused by ecological conditions, not by genetic diversity.