Developing high-yielding and stress-resilient soybean varieties

Soybean is the most widely cultivated legume crop and ranks among the top five crops in the world (Martignone et al., 2023) with a total production of 395 million metric tons in 2023–2024 (USDA, 2024). It provides a significant amount of protein and edible oil for human consumption and is a key source of protein for animal feed. However, soybean production is increasingly challenged by climate-change-related factors such as extreme temperature, water stress, diseases, and insect pests (Landau et al., 2022; Song et al., 2016; Bandara et al., 2020). These will intensify in the coming decades as global temperatures and CO₂ continue to rise (Dijk et al., 2021), threatening food security and farm profitability (Ray et al., 2013). 

To sustain and enhance soybean productivity, breeding programs must focus not only on enhancing current yield levels, but also on improving soybean resilience to biotic and abiotic stresses. It is important to focus on agricultural research, farmer support, and development efforts to mitigate future food shortages and climatic challenges. The U.S. is the second largest producer of soybean after Brazil, accounting for ~30% of global supply with an annual production of 113 million metric tons (USDA, 2024). Its Mid-South region grows approximately 12 million acres (14% cultivation area) of soybean, contributing to about 15% the country's total production (USDA, 2024; Rogers et al., 2015). However, undesirable weather and occurrence of diseases/pests during the growing season poses a significant threat to soybean productivity as it limits the yield potential of soybean varieties (Evans & Fisher, 1999). 

Research efforts at the University of Missouri Fisher Delta Research, Extension & Education Center (MU-FDREEC) have been instrumental in developing improving soybean varieties tailored to region’s unique environmental challenges, contributing to more resilient and productive cropping systems. The MU-FDREEC soybean breeding program aims to develop improved soybean varieties and enhance germplasm for improved productivity, adaptability, and profitability of Mid-South farmers. This article explores the contribution of the MU-FDREEC breeding program, highlighting its role in developing high-yielding, broadly adapted soybean varieties with improved seed quality, multiple disease resistance, and tolerance to environmental stresses.

Why high yield and resilience matter in soybean

Soybean contributes to ~60% of global oilseed production (Martignone et al., 2023). Over the past 80 years, soybean on-farm yield has steadily increased thanks to the dedicated efforts of breeders and agronomists, who have developed and deployed improved soybean varieties (Specht et al., 2014; Boehm et al., 2019). These new varieties offer better yield potential, desirable agronomic characteristics, and resistance to various diseases and pests (Carter et al., 2004). 

To better understand and enhance soybean yield potential, breeders regularly determine their progress by studying genetic improvements in yield over time (Boehm et al., 2019). They focus on selecting varieties that can perform well in different environments. Each year, breeding programs aim to boost soybean productivity by selecting plants with favorable traits including higher yield, resistance to lodging, ability to withstand environmental stresses- drought, weeds and diseases (Rogers et al., 2015).

Beyond yield improvement, varieties with stress resilience offers significant economic benefits by reducing the need for costly inputs—pesticides, herbicides, and irrigation. This not only lowers production costs, but also enhances farm profitability and promotes long-term sustainability. By providing farmers with resilient and productive soybean varieties, breeding efforts contribute to a more stable and sustainable agricultural system capable of meeting the growing global demand for soybean.

Soybean-breeding program achievements 

The MU-FDREEC soybean-breeding program plays a crucial role in advancing soybean production in the Mid-South through innovation and research. This program focuses on developing high-yielding soybean varieties with improved disease resistance and enhanced quality to support farmers’ profitability. In the last five years, MU-FDREEC was able to successfully release 24 new soybean varieties with high yield, resilience, and additional traits (Table 1). Significant contributions by MU-FDREEC have also made in developing a range of soybean varieties, including conventional, Roundup Ready, Liberty, high-protein, high-oleic, and low-linolenic acid content (Table 2). More recently, the program is focusing on releasing XtendFlex and Enlist herbicide traits. One of its most notable achievements is the development of SOYLEIC, a non-GMO, high-oleic soybean trait that eliminates trans fats while maintaining functional properties of soybean oil. These varieties are now commercially produced across 20 states in the U.S. 

In addition to enhancing seed composition and breeding methodologies, the program has achieved great progress in combating key diseases, which are a major threat to soybean production. In collaborations with various institutions across the U.S., MU-FDREEC has identified new genes to improve soybean varieties resistant to these diseases such as soybean cyst and root-knot nematodes, benefiting farmers worldwide. Over the past two decades, the MU-FDREEC soybean-breeding program has grown into one of the top public breeding programs, supplying germplasm and technology to major seed companies for variety development. The program’s sustained commitment to collaboration with farmers, industry partners, and the USDA, ensures that cutting-edge research is translated into real-world benefits, driving agricultural sustainability and economic growth. 

Role of research in developing superior varieties

Research plays a vital role in developing improved soybean varieties by enabling breeders to make informed decisions that balance multiple important traits. While selecting for higher yield over time, breeders also consider other agronomic traits such as lodging resistance, maturity, and pod load. These traits can be indirectly affected by yield selection. Additionally, yield improvement efforts often impact end use quality traits such as protein and oil content, which are known to have an inverse relationship with yield (Boehm et al., 2019). To enhance the breeding program's effectiveness, integrating herbicide incorporation strategies, such as Enlist and XtendFlex, is essential. These technologies not only support weed management, but also contribute to the development of soybean varieties with enhanced herbicide tolerance, ensuring improved agronomic performance and adaptability in diverse growing environments. 

At MU-FDREEC, researchers use advanced breeding methods to accelerate development of improved soybean varieties. One such tool is marker-assisted selection, a method that helps breeders to select plants with superior genetic profiles without the need for extensive field evaluations, improving selection accuracy and reducing breeding time. The use of greenhouses for off-season crossings and winter nurseries in Costa Rica allows rapid generation advancement, enabling the development of new varieties in shorter time. To enhance selection efficiency, the program has recently integrated unmanned aerial vehicles (UAVs) and advanced technologies into the soybean-breeding pipeline, addressing the major bottleneck of phenotyping (Figure 1). Traditional methods are slow and labor-intensive, while UAVs rapidly capture high resolution data across multiple field locations providing valuable insights into plant health, stress response and growth patterns. This accelerates the selection of superior varieties. UAVs are also used for precise herbicide application, improving field management and reducing labor costs. By combining traditional breeding expertise with modern technology, MU-FDREEC continues to develop high yielding, resilient soybean varieties with improved seed quality.

Practical benefits for Mid-South farmers 

The improved soybean varieties developed through research at MU-FDREEC offer significant practical benefits to the farmers in the Mid-South region. With built-in resistance to major diseases and pests in the region, farmers can lower their dependence on pesticides, leading to cost savings and more sustainable farming practices. Improved seed quality traits, such as high oil and protein and a superior fatty acid profile, enhance the marketability of soybean, ensuring better returns for farmers. Several varieties have desired herbicide traits for weed control, including technologies such as Liberty Link and Roundup Ready. Moreover, traits like lodging resistance and optimized plant architecture contribute to easier harvestability and efficient field management. By adopting these advanced soybean varieties, farmers can maximize field productivity, improve profitability, and be more sustainable.

Future directions in soybean breeding

At MU-FDREEC, future soybean-breeding efforts focus on improving yield potential by optimizing photosynthetic efficiency (Koester et al., 2014; Vogel et al., 2021), enhancing resilience to climate change, by developing varieties that can withstand extreme weather events and evolving pests and diseases. Research also aims to improve seed nutritional value to meet growing global demand for high quality food and feed and develop varieties suited for sustainable and regenerative agricultural practices that promote soil health and reduce environmental impacts. By incorporating advanced breeding technologies, such as genomic selection, marker-assisted selection, and precision phenotyping with UAV drones, breeders can efficiently analyze large populations and accelerate the development of high-yielding, stress-tolerant soybean varieties to meet the evolving needs of farmers and agricultural industry. 

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