Effect of Awns on Kernel Weight, Test Weight, and Yield of Wheat¹

Abstract

T HE coordinated wheat improvement experiments at 17 stations in eight western states (3), 3 have offered an excellent opportunity for a study of the performance of awned and awnless wheats under very diverse environments. The problem is of both theoretical and practical interest. Many of the previous experiments with wheat to determine the influence of awns on yield and kernel weight have not been conclusive and no attempt has been made to test similar material at more than one location. In general, awned plants have tended to produce heavier kernels and a higher weight of grain per plant, although this has not always been the case. Clark and Quisenberry (r) and Lamb (2) have reviewed the literature on the effect of awns in wheat.The data on the effect of awns presented here were obtained from composite populations of awned and awnleted segregates from two crosses, one between two winter varieties and the other between two spring varieties. Material for another method of comparing awned and awnless wheats is being developed, but results will not be available for several years. This material is being produced by repeated backcrossing of awnless segregates with the awned parent and awned segregates with the awnless parent. It is planned to continue backcrossing until types similar to the two parents in all genetic characteristics except presence or absence of awns have been obtained. These should be better suited for further studies on the influence of awns on the development of the wheat kernel.

The Influence of Awns on Yield and Certain Morphological Characters of Wheat1

“…Numerous comparisons have been made between awned and awnless varieties or groups of varieties. Early comparisons were made simply by comparing pure varieties of the two types; 3 later pedigreed lines were compared ( 1); and more recently several studies have been made using bulk or specially selected groups of bulk composites from crosses. Bayles and Suneson (3) compared awned and awnless bulk composites• from crosses for 5 years at several locations in western United States.…”

Wheat flour protein content and water absorption analysis in a doubled haploid population

“…A connection between the awn phenotype and yield in wheat has been recognised for some time (Bayle and Suneson, 1940;Rosenquist, 1936). Most of the previous studies have been focused on the awn phenotype ignoring the conferring locus.…”

An Evaluation of Smooth‐awned and Hooded Atlas Barley1

“…A small residue of many characters from the nonrewrrent parent also will persist, unless they are associated with some character that was deliberately discarded ( 4). Backcrossing to produce near isogenic stocks has proved to be a good tool for appraising morphological ( 5) and disease effects ( 3).…”