The chemical markers such as phenolic compounds, have been extensively
used in botanical chemosystematic studies; these last mainly concerne
d the high taxonomic levels: order, family, genus. In consequence of n
ew more sensitive and automatic analytical procedures, it is possible
to approach the metabolic (phenolic) profile of individual genotypes:
so the Micromolecular Biology is born, concerned with the organisation
and functioning of plant populations. Three examples will give suppor
t to this proposal: Dactylis glomerata, Rosa x hybrida, Lotus cornicul
atus.