The effect of the msm1 cytoplasm of barley (Hordeum vulgare L.) on kernel protein and lysine was studied using the near-isogenic, unrestored derivatives of seven barley varieties. With normal lysine varieties, 'Adorra', 'Bomi', 'CI 4362', and 'Hankkija's Eero', the msm1 cytoplasm produced an average of one percentage point more protein than did the normal cytoplasm of the same varieties. There was no difference between the two cytoplasms with respect to their effect on the lysine content. With high lysine varieties, 'Bomi Risø mutant 13', 'Bomi Risø mutant 1508', and 'CI 3947', msm1 produced almost one percentage point more protein but protein with a somewhat decreased lysine content.Induced partial spike fertility in normal 'Adorra' was found to be associated with lysine in meal (r=-0.999), with protein in meal (r=-0.984), and with lysine in protein (r=0.941). Removal of the spikes on the secondary tillers affected both the protein and its lysine content. It is suggested that good spike fertility is an important pre-requisite when selecting high lysine and/or high protein segregants or mutants.