Gene transfer from wild wheat relatives to bread wheat cannot be achieved by homologous recombination because the Ph1 gene on chromosome arm 5BL allows only homologous chromosomes to pair and recombine. The deletion of the Ph1 gene in the mutant stock, ph1b allows also homoeologous wheat and distantly related chromosomes pair and recombine. However, ph1b-induced recombination is low and usually is restricted to distal regions of chromosomes. We have identified chromosome 5Mg from Aegilops geniculata, which escapes the diploid pairing control and freely recombines with wheat in the presence of Ph1, even in proximal chromosome regions where recombination is usually suppressed. Furthermore, in the absence of Ph1, chromosome 5Mg led to vast genome-wide increase in homoeologous recombination including proximal region of chromosomes. Our results demonstrated that 5Mg chromosome can be used in wheat crop improvement by increasing homoeologous recombination between wheat and wild wheat relatives.