Heterosis and Xenia in sorghum malt quality

Abstract

When sorghum hybrids replaced varieties in South Africa, the average malt quality quantified as sorghum diastatic units (SDU) declined. Additionally, malt quality of sorghum needs to be increased if sorghum is to be used as extenders or substitutes for barley malt in the lager beer industry. Trials were carried out in order to study the effect of Xenia and heterosis in F₁ and F₂ seeds produced in various hybrid combinations. Large Xenia effects were observed in the F₁ but this was entirely lost in the F₂ generation. Effectively, most hybrids showed negative heterosis. One R-line seemed to pass on stability in SDU to its offspring. Ways of improving malt quality are discussed.