Ms3 dominant genetic male sterility for wheat improvement with molecular breeding

Authors: Guttieri, Mary

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/16/2019
Publication Date: 4/29/2020
Citation: Guttieri, M.J. 2020. Ms3 dominant genetic male sterility for wheat improvement with molecular breeding. Crop Science. https://doi.org/10.1002/csc2.20091.
DOI: https://doi.org/10.1002/csc2.20091

Interpretive Summary: Wheat is a self-pollinated crop, and the production of a large number of hybrid seeds by cross pollination is technically demanding and labor-intensive. This is in contrast to corn, from which a large number of hybrid seeds can be easily produced by pollinating the silks of one plant with the tassels of another. Breeding strategies that rapidly repeat cycles of crossing and selection have been developed for crop species like corn, but are not used in wheat. A dominant gene for male sterility is used in wheat to promote cross pollination. But this approach has not been productive, in part because it is difficult to sort the fertile plants from the sterile plants before it is too late to control pollination. We have identified a DNA marker that is breeder-friendly and efficient. This marker can be coupled with other marker information to enable wheat breeders to use breeding strategies similar to those used in corn. The new marker also can be coupled with marker-assisted breeding strategies to more efficiently integrate valuable traits into wheat germplasm.

Technical Abstract: Genetic dominant male sterility (DMS) has not been widely used as a breeding tool in wheat, although DMS-facilitated backcross, mass selection, half-sib selection, and S1 family recurrent selection strategies have been described. Our objective was to revisit these strategies using the tools of molecular breeding. Development of a mechanism for seedling identification of sterile progeny was a key component of designing practical DMS-facilitated molecular breeding systems. The DMS gene Ms3 was previously localized to the centromeric region of chromosome 5A. The centromeric location is an advantage because recombination rates are very low. Once identified, a broadly informative marker would reliably predict the male-sterile phenotype. A set of 429 hybrids incorporating Ms3 were constructed, both within U.S. hard winter wheats, and between these winter wheats and Asian spring wheats. Association of the male-sterile phenotype with those polymorphic DNA sequence tags that localized to chromosome 5A was tested using case-control association analysis. Two highly significant (LOD>30) SNP-trait associations were obtained with the male-sterile phenotype. One SNP was developed into a highly sensitive, reliable KASP marker for the Ms3-associated male-sterile phenotype that can be incorporated into marker-supported breeding strategies. Previously described breeding strategies utilizing DMS were updated for trait-targeted marker-assisted backcrossing and gene pyramiding, S1 recurrent selection, and early-generation genomic selection. DMS application to association mapping, with the particular use case of the Multi-Parent Advanced Generation Intercross population, also is described.