Chromosomal location of esterase, peroxidase and phosphoglucomutase isozyme structural genes in cultivated rye (Secale cereale L.).

Isoelectric focusing of esterase (EST), peroxidase (PRX), and phosphoglucomutase (PGM) isozymes in 'Chinese Spring' wheat, 'Imperial' rye and several 'Chinese Spring'/'Imperial' and 'Holdfast'/'King II' addition, translocation and substitution lines revealed the chromosomal location of nine Est loci previously described and of one Prx and Pgm locus. Loci Est1, Est2, Est3, Est5, Est6 and Est7 were found on chromosome arm 5RL, Est8 and Est9 on chromosome 6R in 'Imperial' rye, and the Est10 locus on chromosome arm 4RL in 'Imperial' rye and 'King II' rye. A discrepancy was found between the chromosomal location of the Prx locus in 'Imperial' where chromosome 2R was responsible for the expression of the peroxidase enzyme, and 'King II' with chromosome 1R carrying the Prx gene. As a possible explanation, the occurrence of translocation events during the production of wheat/rye aneuploid lines is discussed. The rye Pgm locus could be associated with chromosome 4RS in 'Imperial' and 'King II' rye. Except for the location of Est loci on chromosome 5RL, the results reported in this paper lend further evidence for the assumed homoeology relationships between the chromosomes of Triticinae and for the conservation of gene synteny groups during the evolution of the Triticeae tribe.