BREEDING SELECTION AND MOLECULAR CHARACTERIZATION FOR IMPROVED SUGAR BEET GERMPLASM
Location: Sugarbeet and Bean Research
Title: Overview of breeding and enhancement activities at East Lansing, Michigan
Submitted to: American Society of Sugar Beet Technologists
Publication Type: Proceedings
Publication Acceptance Date: December 16, 2010
Publication Date: March 2, 2011
Citation: Mcgrath, J.M., Hanson, L.E. 2011. Overview of breeding and enhancement activities at East Lansing, Michigan. In: Proceedings of the American Society of Sugar Beet Technologists. 36th Biennial Meeting, March 2-5, 2011, Albuquerque, New Mexico. 2011 CDROM.
The ARS breeding and germplasm enhancement program at East Lansing, Michigan has been active for over 50 years, and was instrumental in breeding for resistance to Aphanomyces seedling disease, germplasm conversion for hybrid seed production, and developing smooth-root germplasm to reduce soil tare. Throughout this process, the focus has been on practical agronomic conversion to useful varieties and germplasm for the humid, rain-fed, sugar beet growing regions as typified by the Great Lakes region. For many reasons, our understanding of the genetic basis of these traits, and perhaps the majority of traits in sugar beet, has lagged behind our ability to recombine different disease resistances with sucrose yield, as well as application of technologies that would be useful to dissect the genetic basis of useful heritable variation for sugar growers. Three requisites to dissect the genetics of any trait are a (1) a population in which the trait(s) of interest segregates, (2) one or more measurable characteristics, e.g. traits, and (3) a context that allows clarification of the underlying genetic processes (e.g. markers and methods). Sugar beet suffers in the first instance by its complex self-incompatibility system, a trait that precludes self-fertilization for traditional, powerful, Mendelian genetic approaches to trait dissection. Over 10 years of deploying the self-fertility (Sf) allele has allowed developing a number of very interesting populations for genetic analyses. The process of inbreeding has not been as detrimental for fecundity as expected although it is unlikely inbreds would ever supplant hybrids for sucrose production. Traditional germplasm enhancement activities are still a strong component of the program, however stacking traits and resistances in such populations will eventually require marker-assisted approaches. The combination of population and marker development, ongoing, with existing expertise in measuring phenotypic variation is expected to facilitate introgression of novel alleles from wild germplasm as part of a more directed approach to sugar beet germplasm enhancement.