Low responsiveness of six-rowed genotypes to androgenesis in barley does not have a pleiotropic basis

A heterozygous mutant for the two- and six-rowed character was isolated in the barley cultivar Igri through application of sodium azide to isolated mi crospore cultures and posterior regeneration. Six-rowed and two-rowed homoz ygotic plants were subsequently identified in the self-pollinated M-2 proge nies of the original heterozygous M-1. Detailed molecular markers confirmed the isogenic nature of this recovered mutant and the original cultivar Igr i. A comparative study of the anther culture response of this six-rowed ind uced mutant vs. diploid 'Igri' was performed to assess whether the two- or six-rowed gene influences anther culture response in barley through a pleio tropic effect or via linkage disequilibrium. No significant differences for any of the recorded variables throughout the in vitro regeneration process were detected between the 'Igri' six-rowed mutant and any of their two-row ed isogenic lines. This suggests that row-type association with anther cult ure response in barley cultivars is due to the effect of a tight linkage wi th other genes directly responsible for androgenic response.