Performance of Semidwarf Barley1

Abstract

Five to six cycles of crossing and selection have resulted in well‐adapted semidwarf barleys (Hordeum vulgare L.). The original semidwarf stock was a radiation mutant obtained in the Norwegian cultivar, ‘Jotun.’ This report provides a comparison of the performance of these semidwarf barleys and their normal‐height counterparts. Lines from five populations were compared in field environments for yield and 10 other characters. Inheritance information also was obtained using five populations. The semidwarf lines had higher mean yields than the normal lines in four of the five populations, but the yield difference was modest, amounting to 3% for the average of the five populations. Lodging did not influence yield in these experiments. The semidwarf lines had 7% more tillers, 10% more heads, and a 14% higher harvest index than the normal lines based on the mean of five populations. The semidwarfs also had 10% longer coleoptiles than the normal lines, based on the average of four populations. The normal lines were 5% higher in total dry matter and 8% higher in kernel weight. From the results of this study, it appears that the lengthy breeding program has resulted in semidwarf barleys that have potential for direct use as cultivars and as parental material. If so, the effort illustrates an important principle, i.e., capitalizing on "new germplasm" may require a prolonged breeding effort. Results of this study plus our experience in the semidwarf breeding program indicate that a single gene controls the semidwarf character in this material. The symbol suggested for this gene is sdw.