II.22. Some of the barley genetic studies in progress at the Swedish Seed Association.
G. Persson, L. Lehmann, G. Hagberg, P. Hagberg, K.-E. Karlsson, B. Nilsson. Swedish Seed Association, S-268 00, Svalöv, Sweden.
One project is screening for pollen lethals. This is a factor or gene which will eliminate the transmission of a particular chromosome. Both balanced tertiary trisomics for male steriles and heterozygous male sterile populations have been treated with chemical mutagens or with irradiation. We hope to eliminate the transmission of the chromosome carrying the gene for male fertility. This would make it possible to produce barley lines which only produce pollen carrying male sterile genes. These lines could be used as pollinator with homozygous male steriles to produce seed for male sterile populations for hybrid barley production.
In the same treated material, a search is being made for lethals, i.e. albinos which are linked to the male sterile gene. In reality, if this is put into the same plant as the pollen lethals, this would mean all fertile plants would live and produce pollen carrying male sterile genes.
The study of translocation breakpoints is being conducted. Breakpoints are being studied in T5-6's, T4-6's and T6-7's. This includes diallelic crosses of translocations involving the same chromosomes. Pollen fertility of the other diallelic crosses is also studied. Idiograms of the translocation heterozygotes are made. A comparison of the three sets of data is made and the breakpoints are proposed. The first publication on this work is on 20 T5-6's and is to be published in the March issue of Hereditas.
Karl-Erik Karlsson has used marker genes in studying linkage of the lys gene. Along with using translocations in linkage studies, homozygous duplications will be pulled out if the necessary breakpoints and crossovers can be found. Some trisomics with an extra dosage of the lys-gene have been isolated. Auto-tetraploids will also be induced in high-lysine lines to study dosage effect.