VARIATION ASSOCIATED WITH AN AEGILOPS UMBELLULATA CHROMOSOME SEGMENT INCORPORATED IN WHEAT. II. PEROXIDASE AND LEUCINE AMINOPEPTIDASE ISOZYMES

T. Macdonald ¹ and H. H. Smith ¹

¹ Department of Biology, Brookhaven National Laboratory, Upton, New York 11973

Zymograms were analyzed of a number of Triticum aestivum derivatives which incorporated a segment of the Aegilops umbellulata chromosome bearing resistance to leaf rust. Evidence has been presented which suggests that genes involved in the production of two peroxidases and a single peptidase are located on the short arm of wheat chromosome 6B. One peroxidase isozyme, attributed to the presence of the Aegilops segment, was seen in only one of the resistant lines (Transfer) and it was postulated that this peroxidase band was present in a suppressed state in a number of lines. Possible differences in the A and B genomes of T. aestivum and T. dicoccum were discussed.