Genetic and Genomic Tools to Asssist Sugar Beet Improvement: The Value of the Crop Wild Relatives

Abstract

Sugar beet (Beta vulgaris L. ssp. vulgaris) is one of the most important European crops for both food and sugar production. Crop improvement has been developed to enhance productivity, sugar content or other breeder's desirable traits. The introgression of traits from Crop Wild Relatives (CWR) has been done essentially for lessening biotic stresses constraints, namely using Beta and Patellifolia species which exhibit disease resistance characteristics. Several studies have addressed crop-to-wild gene flow, yet, for breeding programs genetic variability associated with agronomically important traits remains unexplored regarding abiotic factors. To accomplish such association from phenotype-to-genotype, screening for wild relatives occurring in habitats where selective pressures are in play (i.e., populations in salt marshes for salinity tolerance; populations subjected to pathogen attacks and likely evolved resistance to pathogens) are the most appropriate streamline to identify causal genetic information. By selecting sugar beet CWR species based on genomic tools, rather than random variations, is a promising but still seldom explored route toward the development of improved crops. In this perspective, a viable streamline for sugar beet improvement is proposed through the use of different genomic tools by recurring to sugar beet CWRs and focusing on agronomic traits associated with abiotic stress tolerance. Overall, identification of genomic and epigenomic landscapes associated to adaptive ecotypes, along with the cytogenetic and habitat characterization of sugar beet CWR, will enable to identify potential hotspots for agrobiodiversity of sugar beet crop improvement toward abiotic stress tolerance.

The effect of heat stress on sugar beet recombination

“…The original sugar beet breeding pool has been considered genetically narrow given its single origin in white fodder beet (Frese et al 2009 ), and there has been a concerted effort in recent decades to broaden the crop’s gene pool. While the introgression of traits from wild relatives, in particular for biotic stress resistance, has been successful (Monteiro et al 2018 ), it has also reportedly resulted in the introduction of undesirable traits from the exotic germplasm though linkage drag (Panella and Lewellen 2007 ).…”

Genomes of the wild beets Beta patula and Beta vulgaris ssp. maritima

“…One of the most important crops is sugar beet as the main source for sugar production, animal feed and sustainable energy in Europe, and competing with sugar cane worldwide. In sugar beet breeding programs, the introduction of wild alleles played and still plays an important role for the acquisition of resistances and for yield improvement (Biancardi et al ., ; Monteiro et al ., ).…”

Structure and floristic composition associated with an endangered species Beta patula Aiton (Amaranthaceae) in the Islands of Madeira Archipelago

“…The source of these genes was obtained from accessions of CWR populations ( Hajjar and Hodgkin 2007 ; Capistrano-Gossmann et al 2016 ) showing their importance for in situ and ex situ conservation. In a recent work, Monteiro et al 2018 ) pointed out the introgression of traits from CWR for decreasing biotic stresses constraints in sugar beets, namely using Beta and Patellifolia species, both having disease-resistant characteristics.…”