Location: Northwest Irrigation and Soils Research
Project Number: 2054-21220-006-000-D
Project Type: In-House Appropriated
Start Date: Jan 24, 2023
End Date: Jan 23, 2028
Objective 1: Identify traits with the potential to increase productivity and sustainability of sugar beet while reducing economic losses due to beet curly top, Rhizoctonia root rot, rhizomania, postharvest storage losses, Cercospora leaf spot, and frost. Sub-objective 1.A: Develop elite germplasm with novel sources of resistance to BCTV, C. beticola, R. solani, BNYVV, and storage rots. Sub-objective 1.B: Develop sugar beet lines with freezing/frost protection. Objective 2: Develop new sugar beet genetic stocks and breeding lines capable of resolving the genetic determinants of agriculturally important traits, and provide the material and markers to breeders for efficient trait utilization. Sub-objective 2.A: Generate experimental populations for gene discovery. Sub-objective 2.B: Generate new and novel agronomically important traits using DNA mutagenesis. Objective 3: Create in-depth genomic resources that are trait-focused and apply molecular genetics methods to decipher the molecular mechanisms, genes, and gene products influencing important phenotypic variation. Sub-objective 3.A: Delineate molecular mechanisms related to diverse traits in sugar beet genotypes exhibiting CLS and rhizomania resistance and the non-bolting phenotype. Sub-objective 3.B: Evaluate the role of sugar beet host-associated bacterial and fungal microbiome in resistance against beet curly top, rhizomania, and post-harvest storage quality. Sub-objective 3.C: Investigate the interaction between different sugar beet germplasm sources and strains of BCTV found in sugar beet to identify different sources of resistance and how their gene expression and molecular resistance mechanisms may differ. Sub-objective 3.D: Develop additional management strategies for beet curly top and pest control in sugar beet.
The Sub-objective 1A research goal is to release elite sugar beet germplasm with novel sources of resistance to Beet curly top virus (BCTV), Rhizoctonia solani, Beet necrotic yellow vein virus (BNYVV), Cercospora beticola,and storage rots. To achieve this goal PI lines and breeding populations will be characterized for their resistance level by screening in disease nurseries. Additional screening will be conducted on germplasm not previously investigated, if novel sources are not found initially. The Sub-objective 1B research goal is to release elite sugar beet germplasm with freezing/frost tolerance by using a leaf syringe agroinfiltration system to transiently express recombinant proteins in sugar beet leaves. Tobacco or Arabidopsis could be utilized to characterize these proteins, if sugar beet is uncooperative. The Sub-objective 2A research goal is to discover novel disease resistance genes by screening progeny of F2 derived, synthetic, and recurrent selection populations, and F3 families in disease nurseries. If extreme weather events are encountered, enough seed will always be saved to allow for additional plantings. The Sub-objective 2B research goal will be to generate new agronomically important traits (such as frost tolerance, non-bolting, etc.) through DNA mutagenesis and link them to specific loci in the sugar beet genome. If no beneficial mutations are identified, the M2 and M3 lines can still be useful for discovery of important genes through loss of function. Sub-objective 3A will test the hypothesis that mutation-induced changes in gene expression and protein/metabolite production in the sugar beet lines will positively affect pathogen resistance and negatively affect bolting. Genomic analysis of sugar beet EMS mutant lines when combined with RNAseq, proteomics, and metabolite analysis will provide genomic markers associated with the trait of interest. If something unexpected happens with the experiments, we have sufficient seed to replicate the experiments. Sub-objective 3B will test the hypothesis that host plant specific microbiome can positively affect disease resistance. Sugar beet leaf microbiome changes based on 16S and ITS sequencing in response to BCTV, BNYVV, and post-harvest storage will be investigated in resistant and susceptible lines. If something unexpected happens with the experiments, we have sufficient seed to replicate the experiments. Sub-objective 3C will test the hypothesis that sugar beet cultivars/lines with different sources of resistance will vary in their response to BCTV strains. BCTV clones will be infiltrated into sugar beet leaves to evaluate their responses in lines previously shown to exhibit differential responses to BCTV strains. If the leaf-infiltration clones prove to be unstable, stab-inoculation clones can be used. Sub-objective 3D will test the hypothesis that seed and foliar insecticide treatments can be used to supplement or extend the control of BCTV and pests beyond that provided by neonicotinoid seed treatments and host resistance by screening in field plots. If extreme weather events are encountered, enough seed will always be saved to allow for additional plantings.