Variation associated with an Aegilops umbellulata chromosome segment incorporated in wheat

The polyacrylamide gel electrophoresis technique for the analysis of soluble plant proteins has amply demonstrated its usefulness and capacity to be repeated. Using the method of disk electrophoresis it is possible to resolve the proteins into a number of fractions, based on their electrophoretic mobility and the molecular sieving action of gels, with high reproducibility. The technique is being used in this laboratory to investigate variation in the spectrum of soluble plant proteins associated with known genetic loci, chromosome segments and individual chromosomes. The observations reported here show variation in protein pattern associated with a chromosome segment from Aegilops umbellulata Zhuk. transferred to Triticum aestivum L. ssp. vulgar (Vill., Host) Mac Key, variety 'Chinese Spring' by Sears. This is of interest as a well analysed example of introgression or translocation of genetic material between allied genera which incorporated resistance to leaf rust (Puccinia triticina Eriks.) in bread wheat. Recent reports indicate that the umbellulata segment is substituted for a terminal piece of the wheat chromosome 6B (ref. 6), is inherited as a single dominant, and controls seedling and field resistance to common races of leaf rust