An Open-Source First- Generation Molecular Genetic Map from a Sugarbeet × Table Beet Cross and Its Extension to Physical Mapping

In sugarbeet (Beta vulgaris subsp. vulgaris), many linkage maps have been constructed, but the availability of markers continues to limit utility of genetic maps in public domain programs. Here a framework genetic map is presented that is expandable and transferable to research programs interested in locating their markers on a consensus map. In its current framework, the primary markers used were amplified fragment length polymorphisms (AFLPs) that were anchored to Butterfass chromosome-nomenclature linkage groups using linkage group specific markers validated in other populations. Thus, a common framework has been established that anchors 331 markers, including 23 newly mapped simple sequence repeat (SSR) markers, having a combined total of 526.3 cM among the nine beet linkage groups. The source of the mapping population was a sugarbeet x table beet population, and this is the first report of a map constructed with a relatively wide cross in B. vulgaris. Segregation distortion was common (22% of loci), particularly extreme for Butterfass Chromosome 5, and predominantly favored the sugarbeet (seed parent) allele. Physical segments of the beet genome that carry mapped markers have been identified, demonstrating that physical and genetic mapping are facile and complementary applications for beet improvement.