IDENTIFICATION OF THREE CHROMOSOMAL INTERCHANGES IN COMMON WHEAT, TRITICUM AESTIVUM L.

Analyzing the F1 P.M.C.s of the crosses between Solo and the 21 monosomic lines of Chinese Spring three chromosomal interchanges involving six wheat chromosomes were identified. 5B/7B involves the longest segments and is already known in other varieties. 7A/7D involves a powdery mildew resistance gene, probably Pm 1 on the distal end of the long arm of chromosome 7A. An attempt is made to explain the deviating segregation ratios of these two aneuploid F2's in the mildew tests. 2A/4D probably involves very short segments since only one single cell out of 1,400 P.M.C.s showed three quadrivalents.