A. C. ZEVEN
Institute of Plant Breeding (I.v.P.) Wageningen, The Netherlands
Introduction
There are several examples of isomeric genes located on homoeologous chromosomes of Triticinae species. Especially the much investigated chromosomes of the A-, B- and D-genomes have given nice examples.
It was considered interesting to investigate whether there are genes on chromosome 2M of Aegilops comosa SIBTH. et SM. isomeric to genes found on chromosomes of 2A, 2B and 2D of Triticum aestivum (L.) THELL.
The genes in question are:
No attempts were made to determine whether any wheat gene localized on 2M also had a corresponding locus. Nor was it intended to settle whether there was a locus of an isomeric recessive wheat gene on 2M at all.
Material
RILEY et al. (1968) developed the following addition line and substitution lines of Triticum aestivum ssp. vulgare (VILL.) MK. cv Chinese Spring (genome formula AABBDD) and the chromosome 2M of Aegilops comosa SIBTH. et SM. (genome formula MM).
Chromosome 2M apparently completely compensate for the absence of the wheat chromosome because the substitation lines look healthy and resemble ssp. vulgare. It carries a gene for a broad spectre of yellow rust resistance now incorporated in the derivative Compair (RILEY et al. 1968). It is not known whether this gene is corresponding to the gene for yellow rust resistance localized on 2A(II) of Thatcher (WELSH et al. 1965).
This material was compared with Chinese Spring which was also received from Dr. R. RILEY, Cambridge, U. K. and was a derivative of the plants used to produce these artifacts.