Genetic differences among barley cultivars and wild oat lines in endogenous seed nutrient levels, initial nitrate uptake rates, and growth in relation to nitrate supply

Abstract

Abstract Net NO3 ‐ uptake rates and internal root NO3 ‐ contents were studied in 9 barley (Hordeum vulgare L.) varieties and 5 genetically pure lines of wild oats (Avena fatua L.). Significant differences in net NO3 ‐ uptake rates and [NO3 ‐]e were found among barley cultivars while the NO3 ‐ uptake rates were only significantly different amoung wild oat lines. No correlation existed between net NO3 ‐ flux and [NO3 ‐]i in barley cultivars. Net NO3 ‐ uptake isotherms were determined for 3 barley varieties, Compana, Fergus, and Betzes, and 3 wild oat lines, CS40, AN51, and SH319. Kinetic constants Vmax and Km, calculated for uptake rates of selected cultivars, indicate that net NO3 ‐ flux was generally higher for Compana than Fergus and Betzes. Although the wild oat lines had similar NO3 ‐ flux rates at higher [NO3 ‐]e levels, CS40 had a higher net flux at lower nutrient levels. Variations in growth characteristics were seen between 9 barley varieties and 5 wild oat lines at 4 different [NO3 ‐]e levels (25,...