The Effect of Species and Cultivation Year on Phenolic Acids Content in Ancient Wheat

During the last decade older (ancient) wheat species, such as spelt (Triticum spelta L.), emmer (Triticum dicoccon Schrank), and einkorn (Triticum monococcum L.) have been recognised as an interesting option to increase the biodiversity of cultivated cereals. The aim of this study was to compare polyphenols content in the ancient species of cereals (including six accessions of spelt, four of emmer, and one of einkorn) cultivated in the three-year controlled plot experiment under organic management. It has been found that the content of almost all free and bound phenolic acids was significantly higher in einkorn than in emmer and spelt wheat species. Moreover, the concentrations of ferulic, p-coumaric, and caffeic acids in einkorn and emmer was higher in dry and very warm cultivation years. It is concluded that ancient wheat species, especially einkorn, could be an important source of phenolic acids in the human diet.

A NEW SUBSPECIES OF WHEAT: TRITICUM DICOCCON ȍSCHRANKȎ SCHUEBL. SUBSP. NUDICOCCON KOBYL. ET SMEKAL.

In recent years, an increased interest in emmer wheat (Triticum dicoccon Schrank) has been observed, due to the dietary value of its grain, which is used for making highquality cereal products. The main disadvantages of this crop are a relatively low yield, if compared with other wheat species, a brittle ear, and problems with grain threshability (filmy kernels are threshed out of the ear together with the chaff). Thus, developing hulless cultivars of emmer is at present an urgent task. Constant lines of naked emmer wheat, which make up the described subspecies, served as the material for this research, including four lines developed at VIR by A. F. Merezhko and seven by V. D. Kobylyansky. The wheat produced from interspecific crosses between different varieties of the hulless T. durum Desf. and various local forms of the hulled T. dicoccon (Schrank) Schuebl. has deserved the rank of subspecies (T. dicoccon (Schrank) Schuebl. subsp. nudicoccon Kobyl. et Smekal.). The obtained hulless wheat demonstrates morphological features characteristic of T. dicoccon: its ear is flat, there are two grains in the spikelet, etc., while its kernels are easily separated from chaff.

Geographic mosaics and changing rates of cereal domestication

Domestication is the process by which plants or animals evolved to fit a human-managed environment, and it is marked by innovations in plant morphology and anatomy that are in turn correlated with new human behaviours and technologies for harvesting, storage and field preparation. Archaeobotanical evidence has revealed that domestication was a protracted process taking thousands of plant generations. Within this protracted process there were changes in the selection pressures for domestication traits as well as variation across a geographic mosaic of wild and cultivated populations. Quantitative data allow us to estimate the changing selection coefficients for the evolution of non-shattering (domestic-type seed dispersal) in Asian rice ( Oryza sativa L.), barley ( Hordeum vulgare L.), emmer wheat ( Triticum dicoccon (Shrank) Schübl.) and einkorn wheat ( Triticum monococcum L.). These data indicate that selection coefficients tended to be low, but also that there were inflection points at which selection increased considerably. For rice, selection coefficients of the order of 0.001 prior to 5500 BC shifted to greater than 0.003 between 5000 and 4500 BC, before falling again as the domestication process ended 4000–3500 BC. In barley and the two wheats selection was strongest between 8500 and 7500 BC. The slow start of domestication may indicate that initial selection began in the Pleistocene glacial era. This article is part of the themed issue ‘Process and pattern in innovations from cells to societies’.