Abstract

Malting barley (Hordeum vulgare) grains contain high concentration of phenolic compounds. Several of these compounds have a high antioxidant capacity reducing oxidative damage and preventing human diseases. However, presence of toxic aluminium (Al) on soils is an important growth-limiting factor that decreases barley yield. The aim of this research was to select barley cultivars based on phenols accumulation in grains and Al tolerance of plants in vegetative stage. Soluble phenols content and distribution were analyzed in grains of 11 barley cultivars. Afterwards, a hydroponic experiment was conducted by using the same barley cultivars, treated with 0 or 0.2 mM Al for 15 days. At harvest, the dry weight and plant growth parameters were determined. In addition, phenol concentration and lipid peroxidation were monitored in plant tissues as an index of oxidative stress. The results showed differencesin concentration of soluble phenols among the grains of the studied cultivars. Likewise, differences in distribution of phenols (e.g. lignin) in grains were found. In the hydroponic assay, yieldand length of shoots and roots of all cultivars were decreased by Al application. This reduction was more marked in the roots than in the shoots. On the other hand, increased oxidative damage was observed in all plants with treated Al. We also observeda differential soluble phenol concentration in plant tissues among barley cultivars as a consequence of Al supply, which could affect the malting quality of grains. Further studies are necessary to clarify this behaviour. Acknowledgments: FONDECYT project 1120901and Dirección de Investigación of the Universidad de La Frontera (Temuco, Chile).