Effect of N-fertilization, fungicide treatment, seed density and abiotic stress factors on the total ß-glucan content of six-rowed winter barley (Hordeum vulgare L.)
In Germany, the first six-rowed waxy winter barley cultivar (cv.) ‘Waxyma’ was registered in 2008. Besides changes in starch composition, waxy barley is rich in ß-glucans offering new applications in the food industry as ß-glucans reduce the blood cholesterol level. To investigate the stability of the ß-glucan content, cv. ‘Waxyma’, three waxy breeding lines and the non-waxy cv. ‘Lomerit’ were grown in field trials, shelter-, green house- and growth chamber experiments. Besides this, ‘Waxyma’ was grown in field trials at varying nitrogen levels and different seed rates, both with and without fungicide treatment. Waxyma showed a significant increase of the ß-glucan content under optimal nitrogen fertilization and fungicide treatment, but the influence of the seed density was not significant. Under shelter and greenhouse conditions, the influence of drought stress during grain filling was analyzed. The increase of the ß-glucan content under drought stress in the shelter and under rising temperatures in growth chambers was only significant for the non waxy cv. ‘Lomerit’ while no influence of drought stress was observed under green house conditions. In summary, the high ß-glucan content of cv. ‘Waxyma’ seems to be relatively stable with respect to growing conditions making it a suitable raw material for human nutrition.