Organic Soybean Breeding

Organic Soybean Breeding

• Istvan Rajcan from the University of Guelph presents an introduction to organic agriculture.
• Soybean is scientifically known as Glycine max (L.) Merr.
• Soybean is considered the world's largest protein and oilseed crop.
• Approximate seed composition includes 40% protein and 20% oil.
• Soybean was introduced from China to the USA in 1765, Canada in 1893, and South and Central America & Europe.
• World soybean production, according to USDA 2022 data, is led by Brazil at 31%, followed by the United States at 30%, and Argentina at 20%. Canada makes up 2%.
• Key crops like rice, maize, soybean, and wheat are crucial for food security and sustainability.
• It is expected that human population will increase exponentially by 2050, and increasing food production is needed.
• Global warming leads to rising land surface and ocean temperatures, caused by increased greenhouse gases like CO2.
• Climate change increases the frequency and intensity of droughts, heat waves, cold snaps, and flooding.
• Climate change directly and indirectly affects crop yields and alters the composition and behaviour of insects and pathogen populations.

Soybean Seed Components

• A soybean is composed of 42% protein, 35% carbohydrates, 19.5% oil, and 3.5% minor constituents.

Soybean Qualities and Uses

• Soybeans are used in nutraceuticals, oils (with a high-quality fatty acid profile), and as a source of protein.
• Many products (>300) are made from soybeans

Canadian Soybean History

• In 1893, Professor Charles Zavitz introduced soybean to Canadian agriculture.
• In the 1920s, professor introduced the first Canadian soybean variety "OAC 211" as a forage soybean

Soybean Production in Canada

• In 2017, Canada had a record production area of 2.95 million hectares, and approximately 42% was grown in Ontario.
• Western Canada surpassed Ontario for the first time that year.
• The total area in 2023 was 5.631 million acres, with Ontario representing 51% of the total.
• Increases in acreage and yield have resulted in a large jump in total Canadian production.
• Manitoba is now the second-largest province in soybean production.
• Manitoba and Saskatchewan have made up for the slowing growth in Eastern Canada.
• Publicly developed non-GM soybean varieties have a higher share in Quebec compared to other provinces

University of Guelph Soybean Breeding

• Since the 1970s, more than 150 soybean varieties have been released by the University of Guelph.
• OAC Bayfield has been grown for more than 20 years.
• Examples of Diverse soybean varieties include OAC Wallace, OAC Kent, OAC Drayton, OAC Avatar, OAC Prescott, and OAC Strive.
• OAC Malory and OAC Kamran are Soybean Cyst Nematode(SCN) resistant.
• VIOLA* and BETTINA* are registered in Austria.
• Many cultivars are registered and grown in Ukraine.

Soybean Breeding Process

• From initial crosses to F2, around 230 crosses are made per year in growth rooms (GR).
• F1 seeds are harvested in April, planted in GR.
• Seedlings are then transplanted in Ridgetown, ON, to leverage the warmer climate.
• F2 seeds are produced in October and sent to Costa Rica for two generation advances via Single Seed Descent (SSD).
• Back in Woodstock, Canada, F4 seed is planted for single plant selection.
• Up to 40,000 plants are planted in the F4 "Costa Rican" nursery in Woodstock, ON, for F4 seed.
• 4000 to 6000 single F4 plants are selected based on visual agronomic appearance.
• Single plant selections are planted the following year as single row plots, 4 m long (F5 "headrows")
• Selection is based on maturity and plot agronomic appearance
• 500-700 plots are selected from the 'headrows' to go into the F4:6 preliminary yield trials (PYT) at one location.
• The PYT with F4:6 lines are planted as un-replicated Completely Randomized Design (CRD) with 5 checks (repeated 3 times).
• 150 to 200 F4:7 lines are grown in advanced yield trials in two locations with 3 reps each.
• 30 to 50 F8 lines multi-location in ON, QC, MB over a 2 year period.
• Breeder seed production is initiated after the first or second year of Ontario yield trials.
• 3 to 5 cultivars released to the seed industry every year.

Organic Agriculture Defined

• Organic agriculture is a management-intensive approach to farming.
• Organic agriculture seeks to take advantage of agroecosystems to enhance crop production
• Organic agriculture is characterized by complex rotations, biological pest control and cyclical fertility systems involving integrated livestock systems.
• This approach is influenced by millennials who are the biggest consumer group, with 77% considering themselves well-informed about organic products

Breeding for Organic Production Systems

• Breeding for organic production is due to conventional varieties are currently used by organic farmers and organic systems encounter more environmental stresses
• Environmental stresses include increased weed pressure and reduced nutrient availability
• The genetics may be different for optimal organic performance.
• An organic ideotype with key traits is important with a cultivar trial to test the traits.
• Key traits in organic farming include Weed Suppressive Ability (WSA) measured in early vegetative growth.
• Key traits also include Nutrient Use Efficiency (NUE) measured at the R5 stage and Root Morphology in the top 20 cm of soil at R5.
• Organic soybean project overall goal: Build knowledge on how to efficiently develop new soybean cultivars for organic growers through plant breeding to maximize competitiveness, efficiency and volume of organic soybean production.
• One objective of organic soybean breeding is to determine differential responses of soybean cultivars/lines between organic vs. conventional systems and to analyze phenotypic traits associated with yield.
• Another objective is to identify and evaluate quantitative trait loci (QTL) for yield under organic systems and compare them to those for conventional systems.

Studies & Findings

• Studies included yield trials with 50 conventionally developed Ontario soybean cultivars.
• Trials were planted in a RCBD, with standard and organic traits measured.
• There were breeding trials using two breeding populations: IR12-055 (OAC Sunny x S05-T6) and IR12-062 (OAC Calypso x DH618)
• The selections were independently compared in organic and conventional fields.
• Physiological traits measured include biomass and root morphology, with detailed analysis of leaf tissue (N, P, K) and root samples (surface area, nodule dry mass) using the WinRhizo program.
• Canopy traits were measured for canopy coverage (V3, V4, V5)
• Green leaf area (GLA) was measured using Green Pixel Count divided by Total Pixel.
• Summary of Physiological and Root Morphology Traits in studies:
• Root surface (RS) significantly higher at Organic vs. Conventional sites.
• Nodule dry mass (NDM) significantly greater at Organic vs. Conventional sites.
• For both traits, much smaller differences between cultivars found at C vs. O sites.
• Conventional seemed to enhance both the RS and NDM and produced greater cultivar differences.
• Leaf tissue N, P, and K are significantly different between Organic and Conventional sites.
• Genotype x environment interaction for production type found for P only.
• Same cultivars accumulated P differently when grown O vs. C sites.
• NDM and yield were negatively correlated - due to plants using more energy to develop nodules on the roots.
• It was found in 2020, that yield generally shows a 20% drop at Organic sites vs Conventional due to problematic weed control.
• Some cultivars performed better at Organic vs Conventional sites:
• OAC Madoc ranked 9th at Organic and 38th at Conventional
• OAC Calypso ranked 1st at Conventional and 23rd at Organic
• OAC Drayton ranked 5th at Organic and 9th at Conventional
• Selection for organic vs. conventional production systems is population-specific.
• Selecting for an organic production system on conventional sites leads to the loss of valuable genotypes.
• QTL associated with performance on organic sites would facilitate organic soybean breeding using Marker Assisted Selection (MAS).
• In conclusion, climate change necessitates enhanced efforts by agronomists and plant breeders.
• Furthermore, various biotic and abiotic stresses are expected to intensify.
• Modern tools like molecular markers and genomics may assist in breeding soybeans for organic systems.
• Important to address weed management for organic sites.