Levels of heterosis for yield and quality in an F₁ hybrid wheat

Abstract

A newly released F1 hybrid wheat (Hybrid Titan) was compared with its parents and three commercial check cultivars in yield trials over 16 site years. Mid-parent heterosis varied considerably (100-127%) over the sites and averaged 111%. However, high-parent and high-check cultivar heterosis levels were much lower (99-119%), most likely a consequence of the low yield of the male parent. A concurrent seeding rate trial showed that lower levels of heterosis resulted if the seeding rate of the hybrid was reduced below that of the parent and check cultivars. Quality tests performed on the harvested grain showed some characters deviating considerably from expected values. The most significant of these were lower milling yield, flour protein content, and water absorption. The T. timopheevi nucleo-cytoplasmic system for producing hybrid wheat was implicated as having likely side effects on yield performance and quality. The study emphasized the need for both parents to be high-yielding and to have good combining ability for both yield and quality.