Outcrossing Rates in Autumn and Spring-Sown Barley

Natural outcrossing is a potential cause of the admixtures which are often observed, especially in winter barley. Outcrossing was studied in yield trials with hap laid -derived homozygous offspring, lines from tour crosses between winter and spring barley varieties. Outcrosses were recognised by heterozygosity in storage protein loci Hor1 and Hor2 as revealed by electrophoresis. Outcrossing, was, on average, about 5% in lines sown in the autumn and less than 0.5% after spring sowing. Autumn-sown lines from one of the four crosses studied had about 10% outcrosses.