Submitted to: Sugar Tech
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 24, 2010
Publication Date: January 26, 2011
Citation: McGrath, J.M. 2011. Assisted breeding in sugar beet. Sugar Tech. 12(3-4):187-193. Interpretive Summary: Plant breeding and improvement have been practiced for millennia, and only for the last few hundred years has the science of genetics been both discovered using plants and applied to plant improvement. These activities rely on populations of plants from which a practical benefit is gained, such as sugar beet from which over half of the sweeter sucrose is derived for human consumption. The genetics of most important productivity traits is imprecisely known, and as technology improves in the 21st century to include whole genome sequences and dense maps of the genome (the sum total of genetic material in an organism), the specific genes controlling productivity are becoming accessible. This paper discusses the present situation of assisted selection in sugar beets and outlines future needs and development. Scientists and policy makers interested in guiding the future of sugar beet research will benefit from this information.
Technical Abstract: Molecular insight and methods applied to plant breeding and germplasm enhancement is the goal of assisted breeding, also known as marker assisted breeding, marker assisted selection, molecular plant breeding, or genome-wide selection, among others. The basic idea is that most, if not all, heritable components of agronomic performance can be assayed with an unbiased, uniform, and comparatively inexpensive set of measures that are highly or completely correlated with phenotypic values. Typically such heritable components are genetically controlled, thus the panoply of DNA-based correlative methods should provide the requisite tools for assisted breeding to be successful. Whether DNA-based methods are successful in predicting agronomic performance depends on a host of considerations, many of which remain to be completely addressed, and thus assisted breeding remains somewhat empirical in practice, at least with respect to the specific traits of interest. Most sugar beet breeding and improvement programs have initiated assisted breeding efforts, primarily as a first step to discover marker associations with traits. These initial activities serve a number of important functions such as determining the complexity of trait inheritance, narrowing the possible range of genes and loci involved in phenotypic expression, and following the progress of sugar beet improvement following hybridization with wild and unadapted germplasm. It is unlikely that breeding will or should ever rely completely on assisted methods, however selection of the most promising germplasm can be greatly accelerated using molecular insights and knowledge.