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Breeding for Fusarium Head Blight Resistance of Nebraska Wheat by Marker-Assisted Selection and Genomic Selection
Abstract
Fusarium head blight (FHB), mainly caused by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schwein.)], is a devastating disease affecting wheat (Triticum aestivum L.) yield, end-use quality, and food safety. The objectives of this study were: 1) identify how marker-assisted selection (MAS) contributes to improving FHB resistance of Nebraska germplasm; 2) create elite lines with Fhb1 through backcrossing for release; 3) evaluate genomic selection (GS) accuracy of Nebraska breeding lines for severity (SEV) and incidence (INC); 4) develop criteria for creating improved training population(s) for better GS accuracy.Six backcross populations were developed by crossing Overland_Fhb1 and six elite Nebraska breeding lines with different FHB resistant levels as recurrent parents. A diagnostic Kompetitive allele specific PCR (KASP) marker was used to track Fhb1 effects in improving FHB resistance of Nebraska winter wheat. By the BC3F1 generation, significant increase in FHB resistance was identified in the heterozygous individuals with Fhb1. The recurrent lines with native FHB resistance had consistently improved FHB resistance with stacked Fhb1. As a result, we recommend ingrogressing Fhb1 into Nebraska breeding lines, especially lines with native FHB resistance using MAS and combining Fhb1 with other available quantitative trait loci (QTLs) to develop FHB resistant cultivars.To investigate the feasibility of historical breeding lines for GS, we conducted a set of cross-validation scenarios by varying composition of training populations. We found that repeatability of SEV and INC from historical data was suitable to perform GS. Based on k-fold cross-validation (Scenario 1), higher prediction accuracy (PA) was obtained from larger training population sizes. The overall PA for INC (0.33 – 0.64) was higher than for SEV (0.20 -0.42). PA was lower when genomic prediction was performed for a testing population from a different environment (Scenario 2). Significant increases were identified (Scenario 3) when a subgroup of experimental lines from new environments were included in the training population. In conclusion, GS is a promising method to improve FHB resistance of Nebraska germplasm.
Subject Area
Agronomy|Genetics|Plant sciences
Recommended Citation
Wang, Fang, "Breeding for Fusarium Head Blight Resistance of Nebraska Wheat by Marker-Assisted Selection and Genomic Selection" (2022). ETD collection for University of Nebraska-Lincoln. AAI29167506.
https://digitalcommons.unl.edu/dissertations/AAI29167506