Effectiveness of Nutrient Solution Culture for Detecting Genetic Variability in Mg Concentration of Orchardgrass (Dactylis glomerata L.)

Abstract

Forage breeding programs to improve tissue mineral concentrations typically are time consuming. However, seedling selection for mineral concentration in nutrient solution culture, if effective, often shortens the period needed for selection. This study was conducted to examine the effectiveness of nutrient solution culture in detecting genetic variability of shoot Mg concentration. Six orchardgrass cultivars differing in Mg concentration were examined for shoot Mg concentration in both a field study and nutrient solution cultures. In the field study, known high-Mg cultivars had significantly higher shoot Mg concentrations than other cultivars at each harvest. The high Mg cultivars also were higher in Ca concentration, and consequently lower in K/(Ca+Mg) ratio than the other cultivars. There were no differences in yield. Three mineral absorption experiments were carried out for seed-lings in nutrient solution cultures. The magnitude of differences among cultivars in Mg uptake per plant were not similar in each experiment. However, Mg densities in shoots were consistent through all three experiments, and the orders of cultivars were similar to the Mg concentration in the field study. Effectiveness of nutrient solution culture in detecting genetic variability of Mg concentration was found in orchardgrass seedlings.