The importance of breeding/genetics for soybean's future

There is no doubt that weeds and disease pathogens have developed/are developing resistance to chemical herbicides and pesticides. There is also no doubt that the soybean genome likely cannot be manipulated to counter the effects of weed infestations, but this is not the case with disease pathogens. In fact, over the last several decades, great strides have been made in developing soybean varieties that are resistant to infection by some of the more devastating nematodes and pathogens such as the one that causes stem canker. This has been done by plant breeders who have worked diligently to find a gene or genes that will allow the soybean plant to resist or avoid infection by outside agents.

It is well-documented that the soybean cyst nematode [SCN] is a major pest of soybean in the U.S. It is also well-known that past active breeding efforts have incorporated resistance to SCN into the soybean genome. However, this resistance–largely derived from PI 88788–is being overcome by the SCN so that it is becoming a less valuable resistance source for soybean producers who are battling this pest. Results from a recent survey by the SCN Coalition show that the number of soybean farmers who are actively managing SCN has increased, along with their knowledge of the tools that can be used in this management and the yield loss when this pest is not managed. This group has also created the SCN Profit Checker so that farmers can estimate the yield and profit loss attributable to this pest. All of this leads to one unmistakable conclusion, which is INCREASED BREEDING EFFORTS IN BOTH THE PUBLIC AND PRIVATE SECTORS ARE NEEDED TO IDENTIFY AND INCORPORATE OTHER SCN-RESISTANCE SOURCES INTO THE SOYBEAN GENOME, AND INCORPORATE THESE RESISTANCE SOURCES INTO VARIETIES THAT ARE AVAILABLE TO SOYBEAN FARMERS. This same philosophy can be applied to all breeding endeavors to impart resistance to pathogens that negatively affect U.S. soybean production.

Climate change is upon us as indicated by the Earth’s rising air temperatures and the increased frequency of violent storms. According to information in an article titled Needs and opportunities to future-proof crops and the use of crop systems to mitigate atmospheric change by Dr. Stephen Long of the Univ. of Illinois, the need for change in the soybean genome is urgent in order to avoid/mitigate the adverse effects from factors that are associated with climate change. Pertinent points from the article follow.

•   A few of the expected future climate changes may benefit crops, but the majority will likely lead to yield losses unless crops are adapted to the anticipated changes.

•   Discovering the genetic traits that will confer beneficial attributes that will allow crop plants to adapt to/withstand climate extremes will require an intensified plant breeding/genetic engineering effort. This will likely require the incorporation of transgenes from crop relatives as well as the editing of the current soybean genome by the more acceptable, non-transgenic gene editing process.

•   More efficient deregulation of key biotechnologies is urgently needed so that plant breeders and geneticists can freely access the tools that are available to make the changes that will be necessary to “future-proof” soybeans against atmospheric change.

There are cases–e.g. crop rotation to reduce SCN populations, early planting to avoid soybean rust infection in the Midsouth–where a production practice is used to thwart the adverse effects from an outside agent. However, in the long term only the enhancement/manipulation of soybean’s genetics can truly thwart the negative effects that will result from climate change and infections by damaging agents. This will require an intensified effort from both the public and private sectors to train plant breeders and geneticists and to develop and use new processes for soybean’s genetic enhancement.

Composed by Larry G. Heatherly, June 2025, larryh91746@gmail.com