Isozyme variations inAegilops andTriticum. III. Chromosomal basis of the esterase isozyme production in different organs of Chinese spring wheat

Developmental changes of esterase isozymes from the germination to the heading stage of normal and aneuploid lines of common wheat,Triticum aestivum cv. Chinese Spring were studied. A total of twenty major isozymes (Bands 1E to 20E) were observed, some of which were further separated to two to three closely located bands. Among these bands, 1E, 2E, 3E, 5E, 7E, 11E, 14E and 16E were found to be leaf-specific isozymes and 9E, 10E, 13E, 15E, 17E and 18E were seed-specific. Leaf-specific isozyme bands 1E, 2E and 5E are controlled by genes on three homoeologous chromosomes group 6, leaf-specific bands 7E, 11E, 14E and 16E and seed-specific bands 9E, 10E, 13E, 15E, 17E and 18E are under control of genes on homoeologous chromosomes of group 3. On the other hand, two bands, 19′E and 19″E are controlled by genes on chromosomes of homoeologous group 2 in roots of seedlings 10 days old. The present investigation showed that the genes for esterase production located on chromosome 6B had large effects in mature leaves, but chromosomes 6A and 6D had little effect on the esterase isozymes in homoeologous group 6. Genes located on chromosomes 3A, 3B and 3D have a large function in germinating seed; however, chromosomes 3B had little effect on the esterase isozymes in the mature leaf. Present findings confirmed that the chromosomes of the A, B and D genomes have different functions in the production of proteins or enzymes. Contribution from the Laboratory of Genetics, Faculty of Agriculture, Kyoto University, Japan, No. 401.