Exploiting novel sources of disease resistance in Beta germplasm using molecular markers

Abstract

Novel disease resistance genes derived from Beta germplasm can be used to improve the durability and effectiveness of disease resistance in commercial sugarbeet (Beta vulgaris L.) cultivars. In order to introgress these genes into sugarbeet, information on their chromosomal location and possible allelic relationships with other genes is required. This information can be provided by mapping the genes using molecular markers. However, to date, few resistance genes have been mapped in sugarbeet compared with other crops. Besides mapping resistance genes, molecular markers can also be used to instigate map-based cloning of genes and for marker-assisted selection of desirable genotypes in a breeding program. We have identified sources of novel resistance genes in a Beta germplasm collection and developed segregating mapping populations. The locations of these genes in the sugarbeet genome are being determined using amplified fragment length polymorphism molecular markers. Mapping a variety of resistance genes acting against different diseases should contribute significantly to our understanding of the locations of resistance genes in sugarbeet.