Phenolic compounds as chemical markers of low taxonomic levels in the family Poaceae

The spectra of non-structural phenolics in herbage were used to study genetic affinity in polyploid complex of Dactylis L., next in complex of octoploid brome species, and in red fescue cultivar collection. The diploid (2n = 14) subspecies of Dactylis revealed distinct differences from the tetraploid (2n = 28) ones as a clearly specialized group. In the genus Bromus the affinity bounds of the species inside the section (e.g. Ceratochloa) were not very tight in comparison to those between the species from various sections. Also remarkable differences in affinity bonds among red fescue cultivars were determined. Although the conclusions are only based on the results from one year and two sites, they bring significant information on exploitation of phenolic compounds. They demonstrate that phenolic profiles could be used in chemical taxonomy of grasses also at low taxonomic levels as a useful marker. As they are environmentally not as stable as the markers of primary metabolism, plant material for analyses should be standardized as to growing condition, growth stages of plants etc.