Discriminative flavonoid patterns within a preliminary collection of the Setaria italica specific complex

Abstract

One hundred and eighty individuals of Setaria italica ssp. italica, reflecting the worldwide variability of cultivated foxtail millet, and 40 individuals of wild S. i. ssp. viridis, were analysed for their flavonoid content. S. i. spp. italica accumulates native or acylated O-glycosyl derivatives of 8- Cglycosylflavones and O-glycosylfiavones, showing a large qualitative as well as quantitative inter-varietal diversity. The subspecies is strongly organized into seven chemotypes clearly defined by the presence or absence of O-pentosylation and acylation, and by the balance between apigenin and luteolin derivatives. This organization only partly corroborates a previous classification based on morphological and electrophoretical data, chemotypes affording an additional discriminative criterion in most cases. Flavonoid patterns of S. i. ssp. viridis fall in the chemotypes defined from the cereal, and underlines the conspecific nature of the two taxa. Similarities between wild and cultivated foxtail millet from same geographical origin suggest independent domestication from already differentiated gene pools.