Drought tolerance of barley varieties in relation to their root system size

P>This study introduces the evaluation of root system size (RSS) for the breeding of barley, in particular for drought tolerance. In 2005-2008, 10-22 varieties of spring barley (Hordeum vulgare L.) were evaluated at two locations (only one in 2007) for RSS by its electric capacity. The RSS was compared with the yield and the quality of the varieties in state registration trials at 7-19 stations each year. Varieties with a greater RSS than the others varieties had a significantly higher yield in the dry year of 2007. Similar relationships between RSS and yield in the other years were found in only some of the environments. Malting varieties with a greater RSS had significantly higher contents of starch, saccharide extracts and malt extracts, as well as higher yields of protein and starch in 2007. It can be concluded that a small RSS is related to a low grain yield and malt quality in dry environments, even in genetically diverse varieties.