Project Methodology
Background
Soybean acreage has dramatically increased in Minnesota during the last four decades, from only 3.0 million acres in 1970 to 7.4 million acres in 2023. A large share of this increase has been in the northern counties of Minnesota. Several factors have contributed to the success of soybean in Minnesota. A very big factor is the development of new soybean varieties that are higher yielding, resistant to pests, and better adapted to the growing conditions and short seasons of Minnesota. At the dawn of soybean production in Minnesota during the 1930s, a farmer could only expect about 15 bushels per acre. By 1980 soybeans grown in Minnesota produced around 30 bushels per acre on average, and today’s soybeans produce around 50 bushels per acre on average across the state of Minnesota. Published studies report that approximately 67% of this increase in yield can be attributed to the development of better varieties through breeding efforts. The foregoing facts demonstrate that soybean breeding is a powerful activity capable of transforming the agricultural landscape and making Minnesota farms more competitive and profitable.
Traits important to Minnesota soybean producers are numerous and varied. Of course, seed yield and proper maturity are the two most important traits. The University of Minnesota program is one of the only public programs in the entire country focusing on the early maturity groups 00, 0 and I. This makes the work being done here critical not only to Minnesota producers, but also to collaborative projects at the regional and national scale. Beyond yield and maturity, the UMN Soybean Breeding program routinely screens for resistance to iron deficiency chlorosis, soybean cyst nematode resistance, Phytophthora root rot, and brown stem rot. Additional diseases and pests can be incorporated in response to new outbreaks, which occurs through collaboration. Communication from growers is welcome to assist us in identifying new pests and diseases to breed against.
In addition to yield and defensive traits, the UMN Soybean Breeding program is important to the development of food-type and specialty soybeans, which provide options to Minnesota producers to enhance profitability. Moreover, maintaining Minnesota’s leadership in the production of food-type and speciality soybeans reduces the supply of commodity soybeans from this region. Food-type soybeans include small-seeded soybeans for natto and soybean sprouts; large-seeded soybeans for tofu and soymilk production; high protein varieties for miso; edamame soybeans; and black-seeded soybeans for specialty food products. The UMN program is also the only program currently introducing high oleic acid into early maturity groups adapted to Minnesota. We will focus on the high oleic soybeans in the coming years to develop products for the Ag Innovation Campus. A non-transgenic approach is being pursued, making these soybeans sellable to all overseas markets.
All food-type soybean and commodity-type soybeans are screened for protein, oil, fatty acid composition, and amino acid composition. Although farmers are not currently directly reimbursed for soybean quality at the farm level, it is imperative that new varieties have high quality because of the demand high quality creates on the international market. About 50% of Minnesota soybeans are exported, and higher quality soybeans result in higher demand for Minnesota soybeans, which ultimately affects the price paid per bushel.
It is widely recognized that the private sector plays the main role in the development of soybean varieties purchased by Minnesota producers. Nevertheless, the presence of a robust public breeding program within Minnesota is just as important as it has ever been. First of all, the varieties and germplasm developed by the UMN Soybean Breeding program are licensed by some seed companies for both direct commercialization and use as breeding parents. The UMN program is at the forefront of identifying and adapting new sources of resistance to insects and diseases, and new combinations of diverse breeding germplasm that hold potential to increase yield. Much of this work is accomplished in collaboration with investigators in plant physiology, plant pathology, entomology, genomics, food science, among other departments. The Soybean Breeding program is an outlet for the research results of scientists in these other disciplines. This high-risk breeding and research is critically important to the long-term sustainability of soybean. In fact, a main interest from major seed increases in UMN germplasm is rooted in its inherent diversity, providing them with some unrelated breeding parents to help them increase yield and prevent plateaus in genetic gain. Thirdly, the MN program conducts research on breeding methodology and provides results to the whole community of soybean breeders and researchers, both public and private. This activity advances the discipline of soybean breeding and genetics as a whole, ultimately helping to create a scientific culture better equipped and educated to deliver improved soybean varieties to farmers over the long term. Finally, the MN Soybean Breeding program educates future soybean breeders who are employed in both the public and private sectors.
Approach
1. Develop commodity and food-type soybean varieties adapted to Minnesota
Variety development is a multi-step process involving crossing between promising parents, inbreeding to create true breeding lines, visual assessment to assess plant health and maturity, and yield and quality trials to generate data that can be used to make selections and identify superior new varieties. Yield trials are classified into preliminary yield trials, new experimental line trials (i.e., advanced yield trials), and regional trials. Regional trials consist of the best lines and are conducted across different states in a cooperative fashion between breeders. Crossing blocks, observation rows, and yield trials are organized based on the intent of the cross (commodity type, SCN resistance, food type, etc.). We routinely evaluate new breeding materials for yield, maturity, seed quality, resistance to IDC, and resistance to SCN.
Specifically, this year, we are going to take a hard look at our breeding procedure and germplasm, and propose some changes to the program to increase yield levels. First of all, we are going to consider a new winter nursery that can provide two generations over the winter. If we can afford this, it will allow us to re-organize our pipeline and test lines earlier. Secondly, we are going to try to source in some new germplasm from private companies and other public programs to increase the yield potential.
2. Conduct public and private variety soybean trials
Each year, the UMN Soybean Breeding program organizes and conducts the Minnesota State Variety trials. Both companies and public institutions are eligible to enter varieties into this trial. The trials consist of two different types: 1) General purpose trial; 2) Special purpose/Food-type trial. The trials are conducted in four zones: far northern, northern, central, and southern. Three locations are planted within each zone. Trials are planted and harvested according to standard practices. Quality and SCN resistance (in the SCN trials) are measured. Results are distributed to the farmers through our new website, varietytrials.umn.edu/soybean.
We will also re-evaluate this program for the future. These trials once served a very important purpose, but the expansion of the private sector trials such as the FIRST trials, we are re-considering the routine planting of these trials. This coming year, we will explore funding models for a complementary set of trials focused on evaluating variety performance following a cover crop treatment. As far as we know, there is not information like this out there, and establishing such a trial system could be beneficial for a future in which more cover crops are planted on soybean acres.
3. Discover and develop new sources of resistance to soybean pests and diseases.
Close collaboration with fellow researchers in plant pathology and entomology creates a dynamic that ties discovery of novel sources of resistance directly with variety development. As soon as putative new sources of resistance are discovered, those sources are included in the UMN Soybean Breeding crossing block. New crosses carrying the new sources of resistance are advanced in the breeding pipeline as described under Objective 1. Examples of projects involving new sources of disease/pest resistance initiated this past year include white mold (Drs. Ranjan and McCaghey), stink bug (Dr. Koch), and stem canker and leaf and stem blight (Dr. Malvick).