Effects of cropping system and genotype on variability in important phytonutrients content of the barley grain for direct food use

In a four-year period (1997-2000), selected phytonutrients, of which the beta-glucan content is most important for human health, were studied in caryopses of different types of barley varieties and lines (standard, waxy, hulless) from two cropping systems. It was significantly highest in the waxy variety Washonubet (4.93%). The whole group of waxy types of barley showed a significantly higher mean content of beta-glucans (4.75%) than the varieties with standard starch composition (4.12%), the starch content, however, was significantly higher in standard varieties (61.98%) than in waxy types (60.30%). The hulless varieties, however, had a significantly higher mean starch content (61.73%) than the hulled forms (61.07%) and a significantly higher protein content (13.82% versus 13.00%). The hulless intensive varieties and lines had a significantly higher content of beta-glucans (4.34%) and protein (13.95%) than the hulled intensive varieties (4.07%, 12.65%). Chemical treatment and fertilization increased significantly only the mean content of protein in caryopses (13.77%) compared to the variants with the absence of treatment (13.13%), the content of beta-glucans and starch increased insignificantly (by 0.12% and 0.27%). Years and varieties participated most in the variability of starch content (31.67%, 28.08%), varieties in the content of beta-glucans and protein (per 22%), and (21%) the interaction of varieties and years in the variability of these two nutrients.