ACONITASE AND GLUCOSE PHOSPHATE ISOMERASE VARIATION IN HEXAPLOID WHEAT

The purpose of this study was to determine if isozyme variation could be found in wheat (Triticum aestivum L. em. Thell) for the isozymes ac onitase, alcohol dehydrogenase and glucose phosphate isomerase; these isozymes are encoded by genes on wheat chromosomes with loci conferrin g pest resistance. Two hundred and fifty wheat accessions were examine d for variation in the isozymes aconitase and alcohol dehydrogenase us ing starch gel electrophoresis. Accessions were chosen at random from a collection of hexaploid wheat lines from all over the world. In addi tion, twenty-one accessions which exhibited unusual variation for eith er endopeptidase or aconitase were examined for glucose phosphate isom erase variation using isoelectric focusing. While no isozyme variation was seen for alcohol dehydrogenase, variation was detected for aconit ase and glucose phosphate isomerase. In addition, the glucose phosphat e isomerase phenotypes of wheat lines with the 1B-1Rs and 1A-1Rs wheat -rye translocations were distinguished. Therefore, evaluation of gluco se phosphate phenotypes could potentially be used in wheat improvement programs to identify plants which are homozygous for wheat-rye transl ocations involving chromosome 1.