Location: Soybean/maize Germplasm, Pathology, and Genetics Research
Project Number: 5012-22000-023-011-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2023
End Date: Sep 30, 2024
Objective:
Determine the effect of soybean vein necrosis virus (SVNV) on plant productivity and evaluate soybean germplasm for resistance to SVNV and thrips.
Subobjectives:
1. Determine the incidence of SVNV infection of thrips over time in the Suction Trap Network (https://suctiontrapnetwork.org/).
2. Evaluate a diverse set of soybean genotypes for resistance to both the soybean thrips and SVNV.
3. Use field cage experiments to evaluate select soybean genotypes without stress and with stress (soybean thrips and SVNV) for plant productivity.
Approach:
Sub-objective 1. Because multiple species of thrips cited have been reported to vector SVNV, thrips from suction traps located in Illinois, Indiana, Iowa, Kansas, Louisiana, Michigan, Minnesota, Missouri, and Wisconsin will be collected, sorted out by species, and counted weekly. The incidence of SVNV infection in thrips will be assayed by real-time quantitative reverse transcription polymerase chaine reaction from subsamples of thrips three times during the growing season. This large-scale monitoring will elucidate the seasonal abundance of thrips and allow correlations with outbreaks of SVNV.
Sub-objective 2. Few genotypes of soybean have been evaluated for resistance to thrips viruliferous or non-viruliferous for SVNV. However, we have developed methods to differentiate soybean genotypes for their responses to SVNV and soybean thrips. A panel of around 350 plant introductions (PIs), which served as a core set selected to represent a broad genetic diversity, will be evaluated for resistance to SVNV. Out of this panel, only PI 171451 has been assessed against SVNV. This PI is resistant to the systemic spreading of SVNV (these results were presented in a previous report). Infection of these soybean lines with SVNV will be done using adult thrips since it has been shown that mechanical inoculation of the virus is not effective. The results will provide broad information about soybean resistance to SVNV and allow for a genome-wide association study.
Sub-objective 3. In preliminary yield trials, open-field experiments with the application of SVNV-infected thrips did not produce significant SVNV symptoms. In contrast, experiments in thrips-proof field cages yielded obvious SVNV symptoms and substantial reductions in yields relative to controls. For FY22, data from open-field yield trials (applications of SVNV-infected thrips), experiments in thrips-proof field cages (SVNV-infected thrips, non-SVNV-infected thrips and no thrips control), and from greenhouse experiments (similar treatments to the field cages) will be further summarized after analysis and manuscripts will be submitted for publication.
