Genetics, Vol 130, 187-194, Copyright © 1992


INVESTIGATIONS

Association Between rDNA Alleles and Quantitative Traits in Doubled Haploid Populations of Barley

W. Powell, WTB. Thomas, D. M. Thompson, J. S. Swanston and R. Waugh
Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland

Doubled haploids (DH) were generated from reciprocal F(1) hybrids which were heterozygous for alleles at the Nor-H3 locus on chromosome 5H of barley. The r-DNA alleles did not deviate significantly from the expected 1:1 ratio and the DH progenies were classified into two groups based on the allelic constitution of the Nor-H3 locus. The DHs were grown in a randomized, replicated field experiment and a range of agronomic and quality traits were recorded. The Nor-H3 locus was associated with a significant portion of the genetic variation for: yield, thousand corn weight, water sensitivity and milling energy requirement of the grain. However, the magnitude of the differences between groups was dependent on the direction of the cross. The milling energy requirement of the grain was consistently associated with alleles at the Nor-H3 locus. These results are presented in relation to the dynamics of rDNA evolution and variability. The potential of molecular markers in conjunction with doubled haploids to map quantitative traits in barley is also discussed.