Potential of publicly available Beta vulgaris germplasm for sustainable sugarbeet improvement indicated by combining analysis of genetic diversity and historic resistance evaluation

Authors: TEHSEEN, MUHAMMAD - North Dakota State University; Poore Fonseka, Rachael; Fugate, Karen; Bolton, Melvin; Ramachandran, Vanitharani; Wyatt, Nathan; LI, XUEHUI - North Dakota State University; Chu, Chenggen

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2023
Publication Date: 4/15/2023
Citation: Tehseen, M., Poore Fonseka, R.C., Fugate, K.K., Bolton, M.D., Ramachandran, V., Wyatt, N.A., Li, X., Chu, C.N. 2023. Potential of publicly available Beta vulgaris germplasm for sustainable sugarbeet improvement indicated by combining analysis of genetic diversity and historic resistance evaluation. Crop Science. 63(4):2255-2273. https://doi.org/10.1002/csc2.20978.
DOI: https://doi.org/10.1002/csc2.20978

Interpretive Summary: Sugarbeet was originally selected from white fodder beet in the 1780s for its higher sugar content. The relatively short history of this crop has resulted in limited genetic resources for sugarbeet trait improvement. Fortunately, related subspecies can be directly crossed with sugarbeet for genetic enhancement and are therefore important resources for improving the sugarbeet crop. A large collection of sugarbeet wild relative species are publicly available in the United States. In this study, all publicly available sugarbeet relatives were analyzed for genetic relatedness to cultivated sugarbeet. These analyses showed that a set of plant collections from sea beet, the ancestor of all cultivated beet crops, exhibited diverse genetic differences to cultivated sugarbeet and therefore have potential for sustainable sugarbeet improvement. Additionally, historic assessments of resistance to various diseases and pests are available in these publicly available plant collections. This information allowed us to associate certain regions in the genome with resistance to disease and insect pests. Taken together, this research identified important genetic resources that can be used to increase sugarbeet sustainability and will facilitate the development of new varieties to improving sugar productivity.

Technical Abstract: Sugarbeet (Beta vulgaris ssp. vulgaris L.) was originally selected from white fodder beet in the 1780s and was then specifically bred for sucrose production. The relatively recent inception of the crop has led to a narrow genetic base that has bottlenecked sustainable improvement. To evaluate the potential of publicly available germplasm for sugarbeet improvement, genetic diversity analysis with SNPs (single nucleotide polymorphisms) covering the whole genome of sugarbeet was conducted using 1,936 publicly available germplasm in the United States. The results confirmed the narrow genetic base of sugarbeet and identified germplasm accessions with inherently greater diversity that were mostly accessions of wild sea beet (B. vulgaris ssp. maritima), the progenitor species of white fodder beet. These wild accessions displayed a distinct genetic distance from cultivated sugarbeet lines, indicating their high potential for broadening sugarbeet genetic diversity. Analysis of historic resistance evaluations also suggested a higher potential of B. vulgaris ssp. maritima accessions to be used as sources of resistance to major diseases and insects of sugarbeet. A genome-wide association study (GWAS) using historic evaluation data identified genomic regions significantly associated with disease and insect resistance; however, genomic regions associated with resistance to insects or diseases vectored by insects were of low significance indicating the need for additional research to allow for a more precise evaluation of germplasm responses to insects. The research confirms that accessions of B. vulgaris ssp. maritima are potentially valuable for improving biotic stress resistance and broadening the genetic base of sugarbeet.