USA
January 21, 2026
Soybean farmers around the world face a persistent and costly enemy hidden beneath the soil: soybean cyst nematode (SCN), a microscopic roundworm that attacks plant roots and drains yields. SCN is one of the most damaging pests affecting soybean production globally, resulting in significant losses every year.
In a new study published in Molecular Plant–Microbe Interactions (MPMI), researchers have uncovered a wealth of previously untapped genetic resistance to SCN by mining deep into soybean genomes.
Most soybean varieties grown today rely on a very narrow set of resistance genes that originated from just a few soybean lines. Over time, SCN has adapted to these defenses, making the resistant varieties less effective and leaving farmers with fewer tools to protect their yields.
To identify new sources of resistance, a research team co-led by Gunvant Patil and Vikas Devkar from Texas Tech University, along with Sushil Chhapekar and Henry Nguyen from the University of Missouri, analyzed the genomes of over 1,100 soybean accessions, including both cultivated and wild varieties. They carefully compared key regions associated with resistance, revealing several soybean accessions with unique genetic profiles that are not found in commonly used resistant varieties. Some of these plants showed strong or broad resistance to multiple SCN populations, meaning they can defend against a wider range of soybean cyst nematodes.
The study also revealed a surprising finding: Soybean lines with similar profiles of known resistance genes sometimes showed very different levels of protection against the nematode. This suggests that additional, previously unknown resistance genes are helping the plant defend against infection, thus opening doors to discovering entirely novel resistance genes and mechanisms.
One soybean line in particular, known as PI 602492, and a wild soybean line PI 522226 stood out for their consistent resistance to several SCN populations. Importantly, their resistance appears to function independently of the genes that dominate modern soybean breeding.
Speaking about these new findings, Gunvant Patil said, “What excites us most is the discovery of entirely new and underutilized genetic sources of soybean cyst nematode (SCN) resistance that work independently of the resistance used in most commercial soybean varieties today.” He added, “Identifying accessions that remain effective against multiple nematode populations offers a real opportunity to overcome resistance breakdown and build more durable protection for soybean crops worldwide.”
Beyond immediate applications, this research highlights the value of wild and exotic soybean relatives, which are often overlooked in breeding programs. These plants harbor genetic diversity that could help future-proof crops against evolving pests under conditions of increasing agricultural pressure and climate change.
For additional details, read the paper “Identification of Novel Genetic Resources for Broad-Based Soybean Cyst Nematode Resistance Independent of Conventional Loci,” published in MPMI.
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