Recombination Promoters

Novel genetics stocks for chromosome-wide enhancement of genetic recombination

Project Summary:

Gene introgression from distant wild relatives into wheat is suppressed by the Ph1 gene, which inhibits homoeologous chromosome pairing and recombination between wheat and wild relative genomes. Though Ph1b deletion allows for increased genetic recombination, the frequency remains too low for effective gene transfer. During Phase I and II, a new homoeologous pairing promotor locus called Hpp-5Mg was identified on chromosome 5Mg of Ae. geniculata, a wild relative of wheat. The combination of Hpp-5Mg with ph1b was found to enhance recombination between wheat and wild relative chromosomes by 100 times, making Hpp-5Mg a valuable tool for introgressing agronomically important genes from wild relatives into wheat. This technology has been patented by Kansas State University (Patent No. 62/405,375, ‘Genetic system for promoting recombination and gene transfer in wheat’).

In Phase II, the Hpp-5Mg was mapped to a distal region of chromosome 5Mg and transferred to an adapted background of a spring wheat cultivar. The goal of this Phase III project is to further improve this technology. This will involve fine mapping of Hpp-5Mg, transferring it to an adapted winter wheat cultivar, evaluating its potential for promoting recombination in both distal and proximal chromosome regions, and developing genome-wide introgression populations in wheat backgrounds for the distant wild relatives described in WGRC IUCRC core activities. The ability of Hpp-5Mg to promote homoeologous recombination opens unprecedented opportunities for the systematic transfer of genetic diversity from wild relatives into wheat. This technology holds great potential for enhancing the breeding efforts of the Center’s partners and improving the genetic diversity and performance of wheat varieties.