Document Type

Dissertation - Open Access

Award Date

2022

Degree Name

Doctor of Philosophy (PhD)

Department / School

Agronomy, Horticulture, and Plant Science

First Advisor

Sunish Sehgal

Abstract

Wheat is one of the most important staple crops providing 20% of energy for 35% of the world population. Fusarium head blight (FHB), primarily caused by the fugal Fusarium graminearum Schwabe, is a damaging disease in wheat that affects global wheat production every year and causes food safety issues. The disease not only reduces the grain yield and quality but also produces mycotoxin in the diseased kernels making them unsuitable for human consumption or as livestock feeds. Breeding FHB resistant cultivar is the most effective and economical approach to managing the disease. This study combines genome-wide association study (GWAS) and genomic approaches (GS) to identify resistance loci/markers and evaluate the efficiency of genomic prediction (GP) in hard winter wheat breeding lines in the South Dakota State University (SDSU) winter wheat breeding program. In the first study, we conducted a multi-locus genome-wide association study (ML-GWAS) with 9,321 high-quality single nucleotide polymorphisms (SNPs) and a panel of 257 elite breeding lines from the South Dakota State University (SDSU) breeding program to uncover the genetic basis of native FHB resistance in the US hard winter wheat. Marker-trait associations (MTAs) were identified with eight different ML-GWAS models, the most appropriate being Fixed and random model Wheat is one of the most important staple crops providing 20% of energy for 35% of the world population. Fusarium head blight (FHB), primarily caused by the fugal Fusarium graminearum Schwabe, is a damaging disease in wheat that affects global wheat production every year and causes food safety issues. The disease not only reduces the grain yield and quality but also produces mycotoxin in the diseased kernels making them unsuitable for human consumption or as livestock feeds. Breeding FHB resistant cultivar is the most effective and economical approach to managing the disease. This study combines genome-wide association study (GWAS) and genomic approaches (GS) to identify resistance loci/markers and evaluate the efficiency of genomic prediction (GP) in hard winter wheat breeding lines in the South Dakota State University (SDSU) winter wheat breeding program. In the first study, we conducted a multi-locus genome-wide association study (ML-GWAS) with 9,321 high-quality single nucleotide polymorphisms (SNPs) and a panel of 257 elite breeding lines from the South Dakota State University (SDSU) breeding program to uncover the genetic basis of native FHB resistance in the US hard winter wheat. Marker-trait associations (MTAs) were identified with eight different ML-GWAS models, the most appropriate being Fixed and random model lines. Our results demonstrate the potential of integrating genomic selection in hard winter wheat breeding to improve FHB resistance.

Number of Pages

188

Publisher

South Dakota State University

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Rights Statement

In Copyright