Location: Crop Production and Pest Control Research
Project Number: 5020-22000-019-000-D
Project Type: In-House Appropriated
Start Date: May 3, 2018
End Date: May 2, 2023
Objective:
Objective 1: Identify new sources of resistance to Hessian fly and aphids in cereal crops for use in breeding programs to reduce damage from these pests and associated pathogens.
Sub-objective 1a. Identify germplasm accessions, from wheat and related species, that confer resistance to Hessian fly.
Sub-objective 1b. Characterize effectiveness against Hessian fly of insecticidal and antifeedant proteins from wheat and other plant sources for potential use as transgenic resistance to pyramid with and protect native resistance loci.
Sub-objective 1c. Identify and evaluate germplasm accessions that confer resistance to wheat against greenbug.
Objective 2: Characterize and evaluate plant-pest interactions at the molecular level in cereals to improve methods of control for insect pests of wheat.
Sub-objective 2a. Compare Hessian fly-wheat and greenbug-wheat interactions among different cereals/grasses to identify genes consistently associated with resistance, susceptibility, virulence and avirulence.
Sub-objective 2b. Investigate timing and composition of overlapping resistance and susceptibility responses when both virulent and avirulent Hessian fly larvae inhabit the same wheat plant, as can happen in field infestations.
Sub-objective 2c. Increased understanding of the molecular basis of the quadratrophic interactions between wheat, greenbug, Buchnera and viruses.
Objective 3: Evaluate germplasm and regional insect populations to assist cereal breeders in selecting effective sources of resistance for their breeding programs.
Sub-objective 3a. Evaluation of wheat breeding lines in regional uniform nursery tests.
Approach:
Objective 1. Resistance phenotypes in new and under-utilized resistant wheat lines will be characterized using genotype-by-sequencing.
Objective 2. The Hessian fly-wheat and greenbug-wheat interactions among different cereals/grasses will be used to identify genes consistently associated with resistance, susceptibility, virulence and avirulence. This will be accomplished by analyzing Illumina HiSeq time-course data of resistant, tolerant and susceptible wheat and the Hessian fly on those hosts. Genes of interest will be verified by quantitative real-time polymerase chain reaction (qRT-PCR). We will characterize the induction of susceptibility also known as obviation. Transcript profiling and qRT-PCR will quantify the abundance of transcripts leading to biomarker genes for compatible and incompatible interactions at a variety of timepoints. In wheat, gene expression differences when infested with aphids carrying barley yellow dwarf virus (BYDV) will be characterized by whole genome mRNA profiles using high throughput sequencing and qRT-PCR. Selected genes of interest that are significantly upregulated or down regulated in both the aphid and wheat will be examined further.
Objective 3. To assist cereal 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 in a greenhouse setting. A variety of insect populations will be used to determine resistance and susceptibility of available wheat lines. The efficacy of resistance Rgene intervention will be assessed by comparing the change in frequency of phenotypic resistance to historical data.
