Additional Potamogeton Hybrids from China : Evidence from a Comparison of Plastid trnT-trnF and Nuclear ITS Phylogenies
Hybridization is a common phenomenon in many plant genera, and among them is the world's largest aquatic genus, Potamogeton (Potamogetonaceae) with about 69 species and 50 hybrids reported. Here we provide genetic insights into Potamogeton hybrids from China, where ten or more putative hybrids exist, of which eight have been genetically confirmed. In the study presented here, we verified the hybrid status and inferred the origins of three Potamogeton hybrids using molecular phylogenetic analyses of plastid (chloroplast) trnT-trnF and nuclear ITS sequence data sets that include previously published and newly generated data. The hybrids identified were: 1) P. ×inbaensis, a known hybrid from Japan; 2) a hybrid between P. perfoliatus s.l. and P. wrightii, and 3) a hybrid between tetraploid maternal P. distinctus and diploid paternal P. octandrus. Potamogeton ×inbaensis is reported from China for the first time, whereas the latter two hybrids are new to science.