II. 41. New data about a gene for branching inflorescent rachilla located on barley chromosome 7.
H.E.B. Larsson, Department of Genetics, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden. "R"
In BGN;ll I reported (Larsson 1981) an earbranching mutant with a bushy multiflorus-like appearance. Because of difficulties in distinguishing phenotypes, my results indicated that the gene for branching is allelic to the gene s for short rachilla hairs. In the summer of 1982 results emerged from a three-point-test that also included the loci for lax-a and for s.
Data now indicate that the new gene is located less than 1 cM distal from the locus for lax-a and more than 28 cM proximal from the s-locus. Taking into account the results also from other authors, the gene may be located still closer to the centromere if there is an inversion around lax-a (Persson 1969).
As a consequence an application is submitted to the International Committee assigning Barley Gene Symbols to change the symbol from si to bir standing for branching, inflorescent rachilla.
References:
Larsson, H.E.B. 1981. Branching spike mutants from two loci in two-row
barley. BGN 11:25.
Persson, G. 1969. An attempt to find suitable genetic markers for dense ear loci in barley II. Hereditas 63:1-28.