The effect of salicylic acid on biofortification with iodine and selenium and the quality of potato cultivated in the NFT system

In contrast to other species of the family Solanaceae, the hydroponic cultivation of potato is not widely used in agricultural (horticultural) practice. This kind of cultivation can be of significance as a model to study the accelerated breeding of new varieties or the biofortification process. The influence of SA on I and Se enrichment of potato plants has not, however, been recognised. Two-year studies were conducted in a greenhouse with hydroponic cultivation of the potato variety 'Vineta' c.v. in an nutrient film technique (NFT) system. They included the application of I (as KIO3), Se (as Na2SeO3) and SA in the nutrient solution. The tested combinations were as follows: (1) control, (2) I + Se, (3) I + Se + 0.1 mg SA.dm(-3), (4) I + Se + 1.0 mg SA.dm(-3), and (5) I + Se + 10.0 mg SA.dm(-3). I as KIO3 was used at a dose of 5 mg I.dm(-3) (i.e. 39.4 mu M I), while Se as Na2SeO3 was at a dose of 0.5 mg Se.dm(-3) (i.e. 6.3 mu M Se). SA was introduced at three doses: 0.1, 1.0, and 10.0 mg dm(-3) nutrient solutions, equivalent to 0.724 mu M, 7.24 mu M and 72.4 mu M SA, respectively. Enriching the nutrient solutions in I, Se, and SA had no significant effect on yield of tubers. The dose of 1.0 mg SA-dm(-3) in combination with I + Se allowed the highest degree of accumulation of I in the peel of tubers, tubers, petioles, and leaves. The combined application of I + Se together with SA (in each of the doses of this acid used) caused a significant increase in the content of Se in the roots, and a decrease of its accumulation in the leaves and petioles. SA had no significant effect on the content of Se in the tubers of potatoes. The obtained level of enrichment of tubers in I and Se was safe for the consumer. The application of I + Se and also SA affected the increases in the contents of N, and Na in tubers and roots, as well as the contents of K in tubers, roots, and leaves. The applied compounds caused decreases in the contents of Mn and Zn in roots.