There was general consent during the 7th IBGS at Saskatoon for changing the barley chromosome numbering system to the current Triticeae homoeologous group numbering system. However, renaming all of the more than a thousand available translocations would be not only impracticable but also bear an extremely high risk for confusion in future. Therefore, it is proposed in the particular case of translocations to retain the traditional barley designations used for their description in the `World Collection' (published in BGNs).

PCR-mediated physical RFLP mapping on microisolated translocation chromosomes was extended to two further chromosomes. In 2H and 6H a number of 33 and 37 breakpoints was integrated into the linearly ordered RFLP markers of the respective Igri/Franka-derived linkage maps (see Korzun and Künzel, this volume of BGN). So far, a total of 179 breakpoints have been exactly inserted into five linkage groups: 1H (38), 2H (33), 3H (32), 5H (39) and 6H (37). Images of physically integrated genetic maps showing the positions of breakpoints relative to the RFLP loci for chromosomes 1H, 3H, 5H and 6H are available on the GrainGenes database WWW.

The 625 translocation stocks, transferred from R.T. Ramage (USDA-ARS) to Gatersleben, were propagated in 1996 for cold storage. Seed samples for all translocations are now available from Gatersleben for distribution upon request.

About balanced tertiary trisomics there are no new informations since the last report in BGN 23.

References:

Korzun, L. and G. Künzel. 1997. Integration of 70 translocation breakpoints into the Igri/Franka-derived RFLP maps 2H and 6H. BGN (this volume).