Location: Crop Production and Pest Control Research
Project Number: 5020-21000-001-000-D
Project Type: In-House Appropriated
Start Date: May 3, 2023
End Date: May 2, 2028
Objective:
Objective 1: Identify germplasm that contains new sources of Hessian fly and greenbug resistance in cereal crops for use in breeding programs.
Sub-objective 1.A: Evaluate and identify diploid wheat that confers resistance against Hf.
Sub-objective 1.B: Evaluate transgenic and elite hexaploid lines for resistance to Hf.
Sub-objective 1.C: Identify new sources of Gb resistance among the Global Durum wheat Panel.
Objective 2: Characterize the molecular mechanisms underlying plant resistance and susceptibility to Hessian fly and greenbug to guide knowledge-based strategies for enhanced insect resistance in cereal crops.
Sub-objective 2.A: Increased understanding of gene regulation during wheat-Gb and wheat-Hf interactions.
Sub-objective 2.B: Determination of wheat cell wall composition in Hf-resistant and -susceptible wheat.
Sub-Objective 2.C: Gb microbiome differences between biotypes feeding on resistant and susceptible wheat.
Sub-objective 2.D: Identify and test function of candidate genes associated with Gb virulence leading to plant susceptibility.
Sub-objective 2.E: Understanding mechanism conferred by HF resistance (R) genes.
Objective 3: Identify and characterize effectors to understand their role in insect virulence and virus transmission in cereal crops.
Sub-objective 3.A: Identify and characterize Hf and Gb effectors associated with insect virulence and plant susceptibility.
Objective 4: Evaluate germplasm and Hessian fly populations in various nurseries to assist cereal breeders in selecting effective sources of resistance.
Sub-objective 4: Regional Uniform Nursery Tests for breeding lines to evaluate wheat germplasm and insect populations.
Approach:
Objective 1. The diploid Aegilops tauschii panel and Einkorn wheat lines will be evaluated for their resistance to Hessian fly and the candidate resistance genes identified will be used to create transgenic and elite hexaploid wheat lines. Durum wheat lines will be evaluated for resistance to greenbug and resistant phenotypes will be further characterized for type of resistance.
Objective 2. Identification and characterization of miRNAs in wheat, greenbug and Hessian fly will reveal genes regulated by miRNA to increase understanding of plant immune and insect virulence. Cell wall changes in wheat will be further examined utilizing glycome profiling to further characterize composition changes in the wall, leading to better management strategies. Greenbug biotype evolution will be examined by focusing on the gut microbiome changes that occur in response to resistant wheat. Genes that are strongly induced in greenbug feeding on susceptible wheat will be knocked down utilizing RNAi in the hopes of understanding aphid virulence. Newly registered synthetic hexaploid wheat will be further examined to understand the mechanism by which the R genes confer resistance to Hessian fly.
Objective 3. Identification and functional characterization of effector proteins in wheat in response to insect feeding will allow for understanding the role these effectors play in regulating wheat-Hf and wheat-Gb interactions.
Objective 4. To assist breeders in selecting effective sources of resistance, we will evaluate germplasm and regional insect populations. New sources of germplasm containing resistance to Hessian fly will be identified using traditional screening procedures. A variety of insect populations and biotypes will be used to determine resistance and susceptibility of available wheat lines. The efficacy of resistance (R) gene intervention will be assessed by comparing the change in frequency of phenotypic resistance to historical data.
