Doubled haploid breeding in cereals

Abstract

Doubled haploid (DH) production has become an important tool in plant breeding largely due to its capacity to produce completely homozygous plants in one generation. Not only are traits fixed for selection but the multiple generations of inbreeding required using traditional breeding methods are circumvented. A major concern of implementing doubled haploid breeding is production costs, which can be divided into two major categories: operational limitations, such as methods of labeling plants and biological limitations, such as the proportion of germinating embryos. Operational efficiencies have been improved and biological impediments reduced to make DH breeding cost effective. However, prior to implementing a DH breeding program, the breeder should consider factors such as the potential for linkage drag, types of crosses to be used and whether production resources are sufficient to produce the DH populations necessary for success. Doubled haploid technology can be integrated with marker-assisted breeding for greater efficiency and to craft the DH population for particular traits. The technology can also be used to accelerate development of germplasm with new genes of interest and to generate cytogenetic stocks. To date, hundreds of DH-derived cultivars have been developed worldwide. In Canada, as much as 30 % of the spring wheat hectarage has been sown to cultivars developed using DH technology. The future for DH breeding is promising because robust DH protocols are available for an ever-growing number of crops and future applications will see a closer integration with molecular-marker and gene-splicing technologies.