Distributive Control of Recombination in Barley: Variation in Linkage in Chromosome 1

Abstract

The variability in recombination fractions was investigated in four barley lines: ‘Alva’, ‘Gull’, WMR, and Laevigatum. The four lines were crossed to two different triple marker lines, homozygous for recessive markers on the short and the long arm of chromosome 1, respectively. Recombination frequencies were estimated by analysis of segregating phenotypes in the offspring of selfed F1 plants. The results show significantly different recombination frequencies among the four investigated lines for both regions of chromosome 1. Positive interference was observed in both regions. The recombination data for the short arm of chromosome 1 are comparable and consistent with results from earlier investigations of the same barley lines and markers. The pattern of variability in the long arm of chromosome 1 differed from that observed in the short arm. Thus, the genetic control of recombination in barley not only specifies the recombination level but also the distribution of recombination events. This result agrees with a previous study of chiasma numbers in the same four lines.