II. 20. Light green seedling mutant on chromosome 6.
K. J. Kasha and A. Ho-Tsai, Crop Science Dept., University of Guelph, Guelph, Ont., Canada. N1G 2W1, "R"
A mutant described as light green seedlings was obtained from C. R. Burnham who had suggested it was associated with chromosome 6. A gene symbol has not been arranged at this time. Our linkage studies confirm that the light green mutant is located on chromosome 6. Based on 67 F3 progenies, the "best-fit" recombination value between light green seedlings and orange lemma was 9 + 2.6%. Linkage studies were also for run light green with interchange stocks T1-6a and T1-7a. The latter showed no linkage, while a value of 10% recombination with T1-6a was obtained, based on 196 F2 plants.
Recombination values for regions between the interchange breakpoint and the centromere are normally very low in barley. Since T1-6a is broken in the satellite of chromosome 6, it is likely that the light green mutant is on the long arm of chromosome 6, probably 8 to 10 crossover units from the centromere. Orange lemma is considered to be very close to the centromere on chromosome 6. The hypothesis of the location of the gene needs to be confirmed with 3-point linkage data.