Yield improvement in high lysine barley

Abstract

Twenty-three barley genotypes were grown in field plots and the seed-yield components and seed composition were investigated. Ten malting and feed cultivars and waxy endosperm selection lines had the standard concentration of lysine in their seed protein. The other genotypes were five different natural or induced high-lysine mutants and/or selection lines developed from them. High-lysine lines were lower yielding than the most productive normal lysine cultivars because of a decrease in weight per seed, accompanied by a reduced content of the carbohydrates extractable with dimethyl sulfoxide. Ris° mutant no. 7 was exceptional in having fewer seeds per unit area and a normal carbohydrate content. Within the group of lys 3 homozygotes derived from Ris° no. 1508, the higher yielding lines had more seeds per unit area, higher concentrations of extractable carbohydrates, and lower concentrations of crude protein. Similar trends with yield also occurred among the lines homozygous for the lys gene from Hiproly. The yields of the most productive lys and lys 3 homozygotes approached that of Clipper, the leading Australian malting cultivar, but were 25% lower than that of the most productive feed barley, Cutter. The other mutants, Ris° no. 7, Ris° no. 29 and Clipper 500, were lower yielding than the better lys and lys 3 selections. The possibilities for improving the yield and energy content of the latter two high-lysine types by selection are discussed.