Breeding for High Tiller Number and Yield in Barley

Abstract

Research was initiated in 1965 to identify and incorporate genes for high tiller number into midwestern six-rowed barley, Hordeum vulgare L. The objective of this paper is to report on the performance, especially yield, of barleys with high tiller and head number from this program. Cyclic crossing, primarily backcrossing, and selection were used to develop high tillering lines that had agronomic promise. When the source of high tiller number was a two rowed barley, XH-263, lines were evaluated after four cycles (Exp. 1) and seven cycles (Exp. 2) of breeding and when the source of high tiller number was six rowed Sel. 6194-63, lines were evaluated after four Cycles of breeding (Exp. 2). Good progress in incorporating the genes for high tillering into a good genetic background was achieved using cyclic crossing and selection. High tillering lines developed in Exp. 1, had better agronomic performance than XH-263, but they were lower yielding than the checks. However, in Exp. 2, the high tillering parents, Minn 73-129 and Minn 75-61, were nearly equal to the checks, Minn 34 and Minn 38, in yield and mean yields of individual high tiller number lines exceeded the checks, although not significantly. In Exp. 2, four groups of lines which differed in tiller number had similar yields. In both experiments, high tillering lines were high in head number and tiller mortality, low in kernel number per head and kernel weight, and susceptible to lodging. Because of high tiller mortality, breeding for increased tiller number was only 36% effective in terms of adding additional heads. We plan to continue this breeding effort since improvement in yield was achieved in the high tillering lines during the several cycles of breeding.