Potential Bioregulators for Rape (Brassica napus L.) Plants

It is known that polyphenols are a single group of phytochemicals which present in all plants. Their biological activity is based upon functional groups capable to participate in the plant metabolism influencing cell division and biosynthesis processes. In our experiments we have evaluated the effect of spruce bark polyphenolic extract and deuterium depleted water (DDW) as rapeseed plant bioregulators. After aqueous extraction of bark and quantification and identification of polyphenolic compounds by HPLC methods, we applied the extracts in the growth medium of rapeseed plants. Assessment the influence of extracts on rapeseed plants was achieved through determination of germination energy and capacity, biomass accumulation, assimilatory pigments accumulation and photosynthesis activity. The results has shown that it possible to establish the highest stimulating effect of polyphenols on germination energy and capacity. These, were registered in the presence of spruce bark polyphenolic extract (SBPE) with an equivalent content of 130 mg GAE/L. Rape plants treated with DDW+SBPE have accumulated the highest amount of biomass compared with other experimental variants. The photosynthesis activity was considerably intensified especially in the presence of SBPE.