Sustainable Soybean Production—Part II

Breeding and variety development will provide advances that arguably will have the greatest impact on sustainable soybean production in the US and the Midsouth, and will provide the genetic resources to enhance Mississippi soybean farming.

The US soybean germplasm collection contains genetic material that can be screened for new traits and genes that will provide enhanced genetics for improved yield potential, host-plant resistance, and enhanced seed traits in forthcoming new varieties. Soybean breeders and geneticists also have access to global germplasms that may have additional genes that can be incorporated into new genotypes to impart resistance to plant pathogens and insects, and management of abiotic stresses.

These resources, coupled with advances in transgenics or biotechnology, have provided and will continue to provide the genotypes necessary to increase actual and net yields through improved resistance to both biotic and abiotic stresses.

The following points emphasize how soybean breeding efforts and advances in genetics research will continue to enhance production sustainability and Mississippi soybean farming.

• Conventional breeding strategies have been and will continue to be successful in developing soybean lines and varieties with traits that improve yield and resistance to pests. Examples are the identification of genes that confer resistance to Asian soybean rust and the development of lines and varieties withresistance to soybean aphid.


• Varieties that possess specialty or value-added traits that improve or enhance seed quality for human food and animal feed uses are available or forthcoming. Examples are the high-oleic/low-linolenic oil lines/varieties and low phytate lines. Development of varieties with these and other enhancements will improve soybean’s position in the marketplace and further contribute to sustainability of production.


• Breeding lines that have traits that will allow soybeans to better withstand periods of drought have been developed, and are available for incorporation into variety-development programs.


• Transgenic varieties with resistance to nonselective herbicides have been and continue to be developed. Forthcoming transgenic traits will impart resistance to more than one herbicide or class of herbicides. An example is the Enlist™ weed management system forthcoming from Dow AgroSciences.


• Both public and private soybean breeding programs currently use transgenic varieties as parent material for future variety development. This allows new soybean varieties to have resistance to multiple pests and herbicides since the new varieties that are developed will build on the transgenic traits present in the parent material.

The challenge for Midsouth soybean breeders and geneticists will be to ensure that past advances that have provided resistance/tolerance to pathogens such as stem canker and nematodes, and herbicides such as metribuzin and glyphosate are not lost in the progressive development of new varieties.
The challenge for Midsouth soybean producers will be to identify specific conditions and pests that can be managed by varietal traits. This will be important since not all varieties will contain all the genetic traits that may be necessary to control problems or conditions that exist in all fields. Thus, using variety yield as a selection criterion should be supplemented with also looking at pest resistance and herbicide tolerance traits in newly-released varieties that become available for use in Mississippi soybean farming.


larryheatherly@bellsouth.net