Tolerance of barley seed germination to cold- and drought-stress expressed as seed vigour

In barley, high seed vigour is a precondition for rapid and homogenous field emergence and good malting quality. Seed vigour was defined as germination percentage under stress conditions (10degreesC, drought stress -2 Bars) in 7-8 barley varieties grown in 7-8 locations in the Czech Republic over 7 years. Three of the 7 years were not suitable for high seed quality, probably because of unsuitable weather, as average seed vigour reached only 61, 77 and 86%, respectively. In the remaining 4 years, the average vigour exceeded 94%. The impact of variety on seed vigour was higher in the 'bad years' and the impact of location was higher in the other years. Varieties with higher vigour from all locations in the 'bad years' were identified. Lower vigour was related to the high occurrence of fungi (indicated by ergosterol assays) and to lower field emergence rates of seed samples. The results support the possibility of selecting for improvement of barley seed vigour, which is related to tolerance to various conditions during emergence and to homogenous malting.