Confirmation of QTL for BPMV Tolerance and Evaluation of Effect of BPMV on Soybean Yields in Tolerant and Susceptible Soybean Lines

Impact on Soybean Production and Value

There is no known resistance to Bean Pod Mottle Virus in soybean. We identified genomic regions that are associated with the amount of virus in the plant, and it appears that the QTLs that limit virus reproduction and/or distribution in the plant may limit the effect on yield loss when BPMV is present.

The more important discovery from this work is that we identified a genomic region, probably a single gene, that is associated with tolerance to BPMV; that is, no yield reduction when the line is infected with BPMV. This is a unique finding that could be useful in developing soybean cultivars with improved yield and stress tolerance.

George Graef, Loren Giesler and Amy Timmerman (2013)


Key Terminology

Alleles are alternative forms of the same gene that are located on different chromosomes.

Near isogenic lines (NILs) are breeding lines that are genetically identical except for specific regions of interest that are associated with a gene, or genes, of interest. This allows researchers to study the effects of the genes of interest without the influence of other genetic variability.

Quantitative traits are traits, or phenotypes, that are influenced by two or more genes and the environment.

Quantitative trait loci (QTL) are regions of DNA that contain, or are closely linked to, genes of quantitative traits.

Recombinant inbred lines (RILs) are lines that are established by crossing two parental strains and inbreeding the resulting progeny. After several generations of inbreeding, the RILs are nearly isogenic and can be evaluated against other RILs to study QTLs.


Study Objectives

This study evaluated a set of soybean recombinant inbred lines (RILs) that exhibited different levels of virus when infected with bean pod mottle virus (BPMV). The objectives were to: 1) Confirm the effect that QTL regions had on limiting the virus amount in tolerant and susceptible lines and 2) Determine the effect that BPMV had on soybean yield in the tolerant and susceptible lines.


Findings

It was determined that BPMV can result in 13% yield loss when a high percentage of plants are infected at an early development stage. QTL that limit virus reproduction and/or distribution through the plant may limit the yield loss associated with infection. More importantly, it was discovered that a single region of the soybean genome, probably a single gene, is associated with tolerance to BPMV so that no yield reduction is observed when the line is infected with the virus.


Next Steps

Current work has begun using DNA markers to identify the candidate genes associated with the tolerant QTL and to create NILs to test and confirm the tolerance response. These results will be important to breed for soybean lines that are tolerant to BPMV.