Sugar beet long-read reference assembly of genotype KWS2320.

Sugar beet (Beta vulgaris ssp. vulgaris) is an important crop plant serving as a major source of sugar, particularly in Europe. Sugar beet research using the genotype KWS2320 has a long-standing history, and many datasets and studies exist that use this genotype as a reference. Here, we present a high-quality genome sequence of sugar beet genotype KWS2320 based on long-read sequencing data as well as an evidence-based gene set employing billions of mRNA (messenger RNA)-seq reads as transcript evidence. The assembly, referred to as RefBeet-3.0, was built using Pacific Biosciences data and was integrated with Bionano optical maps, Oxford Nanopore data, and various additional genomic resources. RefBeet-3.0 comprises 648 Mb in nine pseudochromosomes and further sequences with a total N50 size of 61.5 Mb. The gene set BeetSet-3 consists of 28 271 genes of which 25 824 could be functionally annotated based on sequence homology to orthologous groups. The assembly is highly complete and has a high sequence accuracy in absolute terms and in comparison to existing sugar beet assemblies. RefBeet-3.0 and BeetSet-3 will serve as comprehensive resources for future studies on sugar beet and other plants, as well as for breeding activities.