The University of Minnesota Soybean Breeding program is critical to the development of new early-maturing soybean varieties and incorporation of novel forms of pest and disease resistance into Minnesota-adapted germplasm. The UMN breeding program also conducts a statewide variety trial of both private and public soybean lines, offering an unbiased source of information to farmers for variety selection. We are proposing to build off past success and continue these activities while looking to implement new genotyping and imaging technologies to increase efficiency and throughput. Searching for novel sources of genetic variation controlling seed composition that could lead to new markets will also be an emerging priority over the coming year. The presence of an operating public breeding program is highly beneficial to the development of new-use and specialty-type soybeans in response to demand created by domestic and international markets.

1. Develop general-purpose (both conventional and glyphosate tolerant) and food-type soybean varieties adapted to Minnesota, and new sources of pest and disease resistance for application to Minnesota-adapted varieties.
2. Continue testing public and private soybean varieties available to Minnesota soybean producers.
3. Discover and develop new sources of resistance to soybean pests and diseases.

4. Collect preliminary data on variation among soybean varieties for early-season canopy coverage as a tool for weed control.

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.). Planting at over 13 locations is conducted in May. Trials are designed using a randomized complete block design with less than 50 entries to reduce spatial variation within trials. Notes on stand establishment are recorded in June. Crossing and notes on iron deficiency chlorosis are recorded in July. Greenhouse screening of Phytophthora begins in July. Rogueing off-type plants begins in August. Harvest and notes on maturity begin in September. Visual selections on observation rows occur during October. Samples are collected from each plot and measured for protein, oil, and carbohydrate and fatty acid composition during November through March. Data is analysed for purposes of making selections during November through February. Decisions on variety releases occur in December.

A new goal this year is to increased efficiencies and decreased workload under reduced budgets. We will minimize the number of preliminary yield trials in northern MN, remove smaller sites from our northern region, and cooperate more with private partners to grow and manage plots.

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 www.soybeans.umn.edu as well as through MSRPC.

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.

4. Collect preliminary data on variation among soybean varieties for early-season canopy coverage as a tool for weed control.
Weed control continues to be a major issue for soybean growers. Early season canopy coverage and rapid canopy closure helps to reduce weed pressure through shading of the weeds. A neglected aspect of variety characterization and breeding is canopy coverage. It’s possible that standing variation for early-season canopy coverage exists among commercial varieties. If varieties could be found that have greater canopy coverage, they could be planted to help reduce weed pressure and become another weed control tool.

Through the support of MSRPC, we have developed good capabilities in collecting image data using unmanned aerial vehicles. From these images we can extract precise data on canopy coverage at any given developmental stage if the fields are flown regularly through the season. We will use these data to quantify the variation that exists among commercial soybean varieties for canopy coverage. If substantial variation exists, we will work with weed scientists and use these data to help design future experiments aimed at determining the benefit of variety selection, for canopy coverage, on weed control.

The maintenance of a strong public breeding program within Minnesota gives Minnesota farmers access to more early-maturing variety choices, whether they be commodity-type or food-type. Discovery and development of new traits and sources of resistance helps keep Minnesota soybean production sustainable. The breeding program is a key outlet of gene discoveries made by other researchers on campus. The Minnesota Variety Trials offer an unbiased source of information on variety performance which farmers can use to manage their farm.