Soybean cyst nematode (SCN) is a persistent threat to growers throughout Minnesota. Fields infested with SCN are more susceptible to other disease, pest, and environmental stresses. Moreover, many parts of Minnesota have seen a breakdown in varietal resistance, with the appearance of new SCN races capable of overcoming the widely grown 88788-source of resistance. If fact, three of our testing sites (including Crookston) had SCN populations determined to be of HG Type 2 which are virulent on PI 88788.
Developing new germplasm with alternative forms of resistance to combat resistance breakdown for long-term success is an important function of the public sector breeding efforts. With this in mind, our overall objective is to advance the development of SCN-resistant soybean varieties as well as provide accurate and unbiased sources of information on the resistance of commercial soybean varieties. Our specific aims are to: 1) Enhance the efficiency and efficacy of breeding for SCN resistance through the deployment of DNA markers linked to major genes conferring SCN resistance; 2) Advance new sources of SCN resistance and expand the use of these new sources for crossing in the breeding program; 3) Conduct SCN bioassays on commercial varieties entering the 2023 UMN Variety Trials, as well as all non-88788 commercial SCN varieties available to Minnesota growers.

Goals 1. Continue to efficiently produce new SCN-resistant germplasm and varieties and thus expand availability of SCN resistance across all maturity groups grown in Minnesota.
Objective 1. Deploy DNA markers linked to genes conferring SCN resistance to enhance the efficiency and efficacy of breeding for SCN resistance.

Goals 2. Create elite soybean germplasm with non-88788 sources of SCN resistance so that future soybean growers have more tools in their toolbox to compete with this evolving major pest of soybean.
Objective 2. Advance new sources (non-88788) of SCN resistance and expand the use of these new sources as parents for crossing in the breeding program

Goals 3. Provide an unbiased source of information to growers on the level of SCN resistance in 88788-type commercially available varieties as well as those that have non-88788 sources of resistance.
Objective 3. Conduct SCN bioassays on commercial varieties entering the 2024 UMN Variety Trials using race 3, and conduct bioassays on commercially available non-88788 SCN varieties using races 3 and 14.

1) Public and licensed SCN-resistant varieties, particularly ones carrying the non-88788 source of resistance such as Peking, 567516C, and 90763; 2) An unbiased source of information on the actual SCN resistance of currently available 88788-type resistant varieties to race 3 (HG Type 0); and 3) An unbiased source of information on the resistance of advertised non-88788 resistant varieties to SCN race 1 (HG Type 2.5.7).

Updated June 6, 2025:
Summary
The University of Minnesota has continued to create, advance, and evaluate new elite germplasm for SCN resistance involving both 88788 and non-88788 source of resistance recently focusing on introducing non-88788 sources of resistance. 118 new breeding lines with non-88788 sources of SCN resistance are being evaluated in the yield trials. 1160 new breeding lines with non-88788 sources of resistance are being evaluated in plant rows. Breeding populations F2 and F4 generation are being advanced in two locations: Saint Paul and Rosemount this summer. Fifteen new crosses have been made involving SCN Novel combined with various agronomic traits.

Detailed progress status
The Soybean Breeding Program at the University of Minnesota is focused on introducing non-88788 sources of resistance into the elite MN germplasm, yet also continuing to breed for having SCN resistance in majority of breeding germplasm from the 88788 source of resistance. During this quarter, the primary activities were field monitoring and recording notes for flower/pubescence color. We have also started to record maturity notes in the yield trials as well as breeding nurseries.
We have created 15 new populations this summer making crosses involving non-88788 SCN Resistance trait combined with various agronomic traits like high yield, HOLL, protein and aphid resistance traits as well as black soybeans. Seventeen F2 populations and 22 F4 populations involving non-88788 SCN resistance are being advanced in the breeding nurseries in two locations. The majority of other breeding populations that are being advanced in the breeding nurseries also involve at least one of parents that carry SCN resistance from 88788 source. Approximately 11,000 progeny rows in which most of the progeny rows involve at least one of the parents carrying SCN resistance are also being evaluated this summer. Among these progeny rows, 1160 progeny rows involve the non-88788 source SCN resistance.
The breeding lines that are at least at the second year of regional testing are being screened for SCN bioassay and are also being purified (if not purified already) to produce a source seed for breeder’s seed production in the future. All the breeding lines that made at least AYT are being increased as unpurified seed source for future.
All plots, nurseries and seed increases are in good order, and we expect a successful harvest to produce quality data and seed.

Updated June 6, 2025:
Project summary
The University of Minnesota has continued to create, advance, and evaluate new elite germplasm for SCN resistance involving both 88788 and non-88788 source of resistance recently focusing on introducing non-88788 sources of resistance. This past quarter primarily consisted of the collection of yield data. Yield trial data for the regional trials have been submitted, and data from internal preliminary and advanced yield trials are currently being analyzed. Variety release and advancement decisions will be made once regional trials results are returned. Breeding populations in the F1 and F3 generations have been sent to our winter nursery in Chile and planted there for generational advancement. Five new varieties have been transferred to a private breeding company for breeding work.

Detailed progress status
The Soybean Breeding Program at the University of Minnesota is focused on introducing non-88788 sources of resistance into the elite MN germplasm, yet also continuing to breed for having SCN resistance in majority of breeding germplasm from the 88788 sources of resistance. During this quarter, we harvested all the field trials, curated all the notes and data and regional trial (NUST and SCN UT) data have been submitted to the respective cooperators. We are waiting to receive data from regional cooperators that were evaluated across North America and Canada for analysis and making selection and advancements. Currently, scanning samples with NIR for seed traits, and analyzing data for preliminary and advanced yield trials from last summer.
Fourteen new F1 populations created last summer involving Non-88788 SCN resistance trait have been sent to Chile for generation advancement in winter nursery. These populations involving non-88788 SCN resistance were combined with various agronomic traits like high yield, high oleic-low linolenic (HOLL), protein and aphid resistance traits as well as black soybeans. We also sent ten F3 populations involving non-88788 SCN resistance traits to winter nursery for generation advancement. Many other breeding populations that are being advanced in the breeding nurseries also involve at least one of parents that carry SCN resistance from 88788 source. We have also made thousands of single plant selections from non-88788 SCN resistance F4 populations and threshed them individually to evaluate them in progeny rows next year.
From progeny rows planted last summer, we have selected 318 progeny rows involving non-88788 SCN resistance based on visual evaluation that are combined with high yield, HOLL, aphid resistance, and Phytophthora resistance. We will make further selections based on seed quality traits and advance them for preliminary yield trials accordingly next summer.
We are awaiting the results of SCN Regional Trials before any variety release or transfer decisions.

Updated June 6, 2025:
Project summary
The University of Minnesota has continued to create, advance, and evaluate new elite germplasm for SCN resistance involving both 88788 and non-88788 source of resistance recently focusing on introducing non-88788 sources of resistance. Breeding populations were advanced a generation in Chile. High-yielding germplasm carrying SCN resistance trait including non-88788 sources of resistance were selected to evaluate for another level of yield testing in 2025. A targeted crossing and speed breeding program was initiated in the growth chamber to rapidly introduce new SCN resistance genes conferring resistance to the most virulent SCN populations (HG Type 1.2.5.7) in MG 0 and MG 1 breeding germplasm. We discovered this HG Type in Rosemount, MN meaning it is in Minnesota, and we need to start breeding for resistance now before it becomes too widespread.

Detailed progress status
The Soybean Breeding Program at the University of Minnesota is focused on introducing non-88788 sources of resistance into the elite MN germplasm yet also continuing to breed for having SCN resistance in majority of breeding germplasm from the 88788 sources of resistance. During this quarter, we are advancing the breeding populations in the winter nursery in Chile and making selections for progeny rows, and yield trials for testing within Minnesota (PYT, NEL, and state variety trials including food tests) as well as Northern Uniform Soybean Tests (NUST).
Fifteen new breeding populations created during 2024 crossing season and 10 F3 populations created during 2023 crossing season involving non-88788 sources of SCN resistance are being advanced in 2024-2025 winter nursery in Chile. Most of the rest of the breeding populations also involve at least one of the parents for SCN resistance from 88788 sources. Currently, they are starting to turn for maturity.
For the 2025 field season, we have designed 7,500 progeny rows. Most of the progeny rows involve at least one of the parents carrying SCN resistance in which 1012 progeny rows involve non-88788 SCN resistance source. Over 900 lines involving SCN resistance have been advanced to preliminary yield trial for 2025 field season of which 101 lines involve non-88788 sources of SCN Resistance. Similarly, we have advanced 97 lines involving SCN resistance to advanced yield trials for 2025 field season which includes 15 lines involving non-88788 SCN resistance. Thirty-two lines with SCN resistance have been entered into the Northern Uniform Soybean Tests, out of which seven lines were carry non-88788 SCN resistance source from PI 437654. We have combined non-88788 sources of SCN resistance with various traits including HO/HOLL and high protein, along with other resistance traits such as Phytophthora resistance and aphid resistance.
To create new non-88788 SCN resistance lines, we designed four new crosses and planted them in growth chamber this winter involving two non-88788 SCN resistance. One of them is resistant to HG type 1.2.5.7. Currently, the plants are flowering, and crossings are being attempted. We will also design several new crosses involving both of 88788 SCN resistance source as well as non-88788 source this summer.
In addition to testing and evaluating germplasm using both internal and regional, we have distributed germplasm carrying SCN resistance to interested private companies. Several breeding lines have also been distributed to private parties for testing and possible licensing for commercialization and several of them have been licensed.
Several Minnesota lines that demonstrated promising performance in regional tests and/or advanced to another year of testing have been presented in the Tables below. All the Minnesota lines listed in the performance tables below have strong SCN resistance.

Three-Years Summary in SCN Regional Tests – MG I, 2022-2024
Strain Seed Remarks
Yield Maturity Lodging Height weight quality protein oil
bu/a date score in. g/100 score @0% @0%
#Tests 29 27 23 28 27 27 25 25

MN1511CN 54.1 Sept 16 1.4 33.5 15.3 1.5 39.7 21.9 Check
ND Dickey 49.6 Sept 13 1.1 28.1 18.1 1.5 40.7 21.6 Check
MN1905CN 62.5 Sept 23 1.3 33.1 17.7 1.6 40.1 22.5 Check
E15338 60.7 Sept 21 1.6 33.0 17.1 1.5 39.2 21.8 Check
M16-214187 61.7 Sept 20 1.5 29.8 16.1 1.6 38.9 22.2 SCN


Two Years Summary in SCN Regional Tests – MG 0, 2023-2024
Strain Seed Remarks
Yield Maturity Lodging Height weight quality protein oil
bu/a date score in. g/100 score @0% @0%
Locations 13 14 14 12 12 12 11 11

ND Dickey 46.5 Sept 22 1.4 30 17.9 1.2 40.1 20.6 Check
MN0095 40.2 Sept 16 1.4 29 14.1 1.6 40.2 21.4 Check
MN1511CN 51.4 Sept 28 1.6 38 15.0 1.4 39.1 21.1 Check
M17-148028 47.3 Sept 24 1.6 36 18.0 1.8 40.3 20.8 SCN
M17-152020 47.7 Sept 24 1.7 33 18.1 1.8 41.2 21.1 SCN



SCN Regional Tests Summary – MG I, 2024
Strain Seed Remarks
Yield Maturity Lodging Height weight quality protein oil
bu/a date score in. g/100 score @0% @0%
#Tests 9 9 7 10 9 9 8 8

MN1511CN 55.1 Sept 17 1.4 34 15.5 1.5 39.6 21.8 Check
ND Dickey 53.4 Sept 14 1.2 28 18.2 1.5 40.7 21.6 Check
MN1905CN 67.5 Sept 22 1.5 31 16.6 1.4 38.2 23.3 Check
E15338 67.0 Sept 21 1.2 30 15.3 1.4 38.1 22.9 Check
M18-105005 58.6 Sept 19 1.3 31 17.3 1.6 40.1 22.2 R-SCN, High Pro
M18-167057 61.7 Sept 21 1.3 33 17.9 1.6 40.3 22.3 R-SCN HG 1.2.5.7


Northern Uniform Soybean Tests, 2024
Seed
Yield Maturity Lodging Height Size Quality Protein Oil
No. of Tests 8 10 9 8 10 10 10 10
Strain bu/a Date Score In g/100 Score 0% 0%

MN0083 42.0 Sept 16 1.4 29 14.2 1.6 41.0 20.4
MN0095 49.7 Sept 18 1.3 28 13.9 1.7 39.4 21.2
ND Rolette 47.6 Sept 17 1.1 29 13.8 1.6 39.8 20.7
M18-219013 49.4 Sept 21 1.4 29 16.9 1.6 40.5 20.9

Updated June 6, 2025:
Annual Progress Report, 2024
Advancing Varietal Resistance to Soybean Cyst Nematode in Minnesota
PIs: Aaron Lorenz and Senyu Chen

Objectives

The objectives of this project and related accomplishments were as follows:

Goals 1. Continue to efficiently produce new SCN-resistant germplasm and varieties and thus expand availability of SCN resistance across all maturity groups grown in Minnesota.

Objective 1. Deploy DNA markers linked to genes conferring SCN resistance to enhance the efficiency and efficacy of breeding for SCN resistance.

During the summer of 2024, nearly all of our ~100 crosses included at least one parent specifically targeted for SCN resistance were made. All crosses were successfully made and F1 seed was sent to Chile. F2 seeds were returned in time for planting.

F2, F3, and F4 breeding populations previously targeted for SCN resistance were advanced successfully using winter and summer nurseries per standard operating procedures.

In 2024, we genotyped 1388 F4:5 plant rows for SCN resistance These plant rows were targeted for harvest and we harvested each family. Using molecular markers to select which individual plants have SCN resistance greatly enriches our breeding pipeline for SCN resistance. Without this funding to use these markers, we would have a much harder time breeding for SCN resistance.

This is evidenced by the number of SCN resistant breeding lines we entered into the SCN regional trials. In 2024, we entered 20 advanced breeding lines. All but three of these lines was determined to in fact have resistant according to a greenhouse bioassay, indicating the effectiveness of our marker program. Many of the resistant lines performed well in terms of yield and overall agronomics.

We transferred five lines to private companies this reporting period for testing prior to either direct commercialization or breeding.





Goals 2. Create elite soybean germplasm with non-88788 sources of SCN resistance so that future soybean growers have more tools in their toolbox to compete with this evolving major pest of soybean.

Objective 2. Advance new sources (non-88788) of SCN resistance and expand the use of these new sources as parents for crossing in the breeding program

During the summer of 2024, 15 successful crosses were made between adapted soybean varieties and breeding lines or exotic accessions carrying putative novel SCN resistance genes. New sources ranged from Peking sources, as well as some new sources from the germplasm collection that appear to be novel. The F1 seeds resulting from these crosses were sent to Chile for generational advancement. F2 populations were successfully generated from these crosses and have been returned from Chile and planted in the St. Paul breeding nurseries for generation advancement. Additionally, we advanced 17 F2 populations and 22 F4 populations segregating for new sources of SCN resistance. The F4 populations were harvested as single plants based on genotype data, threshed, and planted in 2025 as plant rows. We have 1160 new plant rows being grown in 2025 with novel SCN resistance as a result of this project!

Breeding lines developed from crosses with novel sources of resistance back in 2019 have been advanced to multi-location yield testing. From 1300 plant rows with novel resistance planted in 2024, we selected and harvested 97 for preliminary yield testing in 2025. Of the 102 tested in preliminary yield tests in 2024, 15 were advanced to a second year of testing at three locations in 2025.

One major development during this last year of the project was the discovery a new breeding line with resistance to HG Type 1.2.5.7. This population of SCN has the ability to overcome both the 88788 and Peking sources of resistance, and it has been discovered in Minnesota. This new breeding lines (M18-167052) showed resistance to this source of resistance in a greenhouse bioassay. We are currently planning a series of crosses with this breeding line to introduce this resistance into higher yielding and earlier varieties to expand more sources of resistance for Minnesota soybean growers.



Goals 3. Provide an unbiased source of information to growers on the level of SCN resistance in 88788-type commercially available varieties as well as those that have non-88788 sources of resistance.
Objective 3. Conduct SCN bioassays on commercial varieties entering the 2024 UMN Variety Trials using race 3.
We successfully published this report at
https://varietytrials.umn.edu/soybean

Soybean cyst nematode is the number one pest of soybean, causing large yield reductions wherever it is present in the soil. By far and away the best tool for ameliorating yield losses from SCN is to plant soybean varieties with genetic resistance. Development of varieties with strong resistance is not an easy task as SCN resistance screening is expensive and laborious. It is even possible that commercially available varieties claiming to have SCN resistance do not in fact have such resistance, or the resistance is only moderate. On top of all this, the most commonly deployed source of resistance – 88788-type resistance – has been in use for several decades. Reports of resistance breakdown have become increasingly common in Minnesota, and it is expected the situation will become rapidly worse. New sources of resistance are needed to sustain soybean production.

The research conducted as part of this proposal addresses all three of the above-mentioned issues. Firstly, this project funds the deployment of molecular markers that assist in the selection of SCN resistance. Each year, the UMN Soybean Breeding program screens 3000 – 5000 breeding line candidates for resistance, thus greatly enriching the probability an advanced variety has SCN resistance. During 2024, we made sure that all breeding crosses made contained SCN resistance, a scenario made possible only through these molecular markers. We are also converting many food-type varieties to having SCN resistance, and are having some success: new natto cultivars with SCN resistance have been advanced to foundation seed production and sent out to several potential commercial partners for evaluation.

The incorporation of new sources of resistance into elite varieties adapted to Minnesota is an ongoing long-term project. Nevertheless, it is an important endeavor to help assure that such varieties exist in the future. We have continued to make new breeding populations with new sources of SCN resistance, which will be important sources of new varieties in the future. These are currently progressing through our population developing and yield testing pipeline. Througout this ongoing process, we discovered new breeding lines with resistance to HG Type 1.2.5.7, the most problematic population of SCN discoverd in Minnesota to-date. We will recycle these breeding lines in our breeding program to improve yield in early-maturting backgrounds so that MN farmers have access to more sources of resistance in the future.

The proposed research addresses three areas targeted by the Production Action Team’s mission statement: (1) Plant breeding and genetics; (2) Molecular breeding and functional genomics; (3) Soybean cyst nematode (SCN). The work we propose aims to increase soybean yield and profit potential by providing growers with a broader range of variety options with stable or enhanced yield even in fields infested by SCN. To increase the utility of our work, we are introducing novel sources of resistance into Minnesota soybeans, combining SCN resistance with other marketable traits, and making our germplasm available to the broader community to catalyze additional variety development for the future benefit of Minnesota growers. We will also provide an unbiased source of information on the SCN resistance of commercially available varieties. This is particularly important for the non-88788 varieties, which have not been verified in this way before.