Genetic analysis of the inheritance of glutamate oxaloacetate transaminase (GOT), acid phosphatase (ACP) and diaphorase (DIA) in leaf tissue of rye revealed the involvement of four Got, four Acp and three Dia loci. Linkage analysis led to the arrangement of these and other previously described isozyme loci into four linkage groups located on chromosomes 3Rq, 4Rq, 6R, and 7Rq, respectively. Implications of these findings for possible translocation differences between chromosomes of S. cereale and S. montanum are discussed. A χ (2) component analysis which makes use of the entire potential of the information provided by codominantly inherited traits such as isozymes is described.