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Identification of Stemborer [Dectes texanus Leconte] Resistance in Soybean [Glycine max (L.) Merr.] and Evaluation of Leghemoglobin (LBC2) Expression in Seed
Increased demand provides technological opportunities to increase or protect production and stabilize demand with expanded market interest. Modern breeding methodology using DNA-based markers and biotechnology can provide valuable genetic variation resources for product development with yield protecting traits and reduce time to market. One major yield protecting trait is for insect resistance. To aid advancements in crop protection we chose to search soybean germplasm for resistance to a specific insect and to expand market interest we partnered with Impossible Foods to design a soybean line for their plant-based meats. In chapter 1, we present what is known about the stemborer, Dectes texanus Leconte (Coleoptera: Cerambycidae) biology and biocontrol along with Genome wide Association Study (GWAS) for insect resistance loci identification. Chapter 1 also contains information on Plant Based Meat Alternatives (PBMAs), hemoglobin structure and function, and specifically leghemoglobin’s association PBMAs and Impossible Foods. Increased insect resistance is a yield protecting trait while the use of soybean in PBMAs protect by increased market interest. In chapter two, field trials were conducted in 2020 and 2021 in Nebraska and Kansas. A total of 960 lines within maturity groups I-IV, comprised of 720 accessions from USDA germplasm and 240 NE-Elite, were screened for larvae infestation. The 720 accessions were also screened for girdled stems caused by D. texanus. In chapter three D. texanus resistant loci were identified in lines that have been previously genotyped with 50,000 SNP markers using the SoySNP50k Illumina Infinium. There are three GWAS using the 713 accessions within maturity groups I-IV and two GWAS using 379 accessions within maturity groups V-VII tested in North Carolina 1972 and 1973 field and cage trials. All GWAS were ran using the FarmCPU model built in the R package, GAPIT. Then in chapter four, legume hemoglobin in soybean for the use of PBMAs was explored. The nodule only expressing legume hemoglobin, LBC2, was transiently expressed in soybean seed deploying vectors which differed in LBC2 sequence and target organelles. Molecular characterization with southern blot, western blot, and immunolabeling microscopy analysis confirm transgenic allele integration and expression.
Johnson, Sarah E, "Identification of Stemborer [Dectes texanus Leconte] Resistance in Soybean [Glycine max (L.) Merr.] and Evaluation of Leghemoglobin (LBC2) Expression in Seed" (2023). ETD collection for University of Nebraska - Lincoln. AAI30575991.