Identification of alien Fallopia taxa using molecular methods

The non-native species of knotweeds (Fallopia sect. Reynoutria) are morphologically very similar and it is often difficult to distinguish between the hybrid F. ×bohemica and parental taxa, F. japonica and F. sachalinensis. To distinguish 30 samples of knotweeds, collected in Slovenia, we used PCR RFLP analysis of the trnK intron of plastid DNA in combination with the amplification of microsatellite nuclear locus KW6, which is a specific diagnostic marker for F. sachalinensis. We established that the combination of both markers unambiguously identifies the following samples: F. japonica (var. japonica), F. sachalinensis and F. ×bohemica. Basedon described molecular markers we confirmed that the maternal parent of the taxon F. ×bohemica was F. japonica for all analysed hybrids. In addition, two species from Fallopia sect. Sarmentosae (F. baldschuanica and F. multiflora) were also analysed.Both could be distinguished from species of Fallopia sect. Reynoutria, but for the discrimination between them, some other markers should be used.