Despite conservation of the process of meiosis, recombination landscapes vary between species, with large genome grasses such as barley (
Hordeum vulgare
L.) exhibiting a pattern of recombination that is very heavily skewed to the ends of chromosomes. We have been using a collection of semi-sterile
desynaptic
meiotic mutant lines to help elucidate how recombination is controlled in barley and the role of the corresponding wild-type (WT) meiotic genes within this process. Here we applied a combination of genetic segregation analysis, cytogenetics, and immunocytology to genetically map and characterize the meiotic mutant
desynaptic5
(
des5
). We identified an exonic insertion in the positional candidate ortholog of
Disrupted Meiotic cDNA 1
(
HvDMC1
) on chromosome 5H of
des5
.
des5
exhibits a severe meiotic phenotype with disturbed synapsis, reduced crossovers, and chromosome mis-segregation. The meiotic phenotype and reduced fertility of
des5
is similarly observed in
Hvdmc1
RNAi
transgenic plants and
HvDMC1
p:GusPlus reporter lines show DMC1 expression specifically in the developing inflorescence. The
des5
mutation maintains the reading frame of the gene and exhibits semi-dominance with respect to recombination in the heterozygote indicating the value of non-knockout mutations for dissection of the control of recombination in the early stages of meiosis.