Establishment of a monosomic series of Yogo winter wheat

Carl R. HAUN and J. SCHULZ-SCHAEFFER

Montana State College, Bozeman, Montana, U.S.A.

Transference of the monosomic condition from an aneuploid series of Chinese spring wheat to Yogo winter wheat was initiated during the winter of 1956-57, when the first crosses were made in the greenhouse. F₁ hybrids, grown in the winter of 1957-58, were examined cytologically, and those presumed to be monosomic were backcrossed to Yogo. It is planned to continue the backcrossing program until a series of Yogo, monosomic for each of the 21 chromosomes, has been obtained. This aneuploid Yogo series will then be used in a chromosome-substitution program with certain other winter wheat varieties in an effort to determine which chromosomes carry factors affecting milling and baking qualities, as well as agronomic characters. The problem will then be to combine the desirable chromosomes into a winter wheat variety suitable to our climatic conditions.

(Received May 10, 1958)