It's been nearly 70 years since soybean cyst nematode was discovered in North Carolina, and the first varietal resistance was introduced in 1965. However, SCN is still the leading cause of soybean yield loss.
Heavy reliance on a single source of native genetic resistance with the PI88788 gene in commercial soybean lines is resulting in nematode populations that can overcome or partially overcome the resistance. There's urgent need for new answers to this old problem.
"The primary reason PI88788 was used for so long is that as a single gene, it was easy to breed with," said Tim Pruski, BASF soybean breeder. "And, it was really effective for a long time. But nothing lasts forever. Nature finds a way."
In a special species called Seed Solutions, DTN/Progressive Farmer examines many aspects that contribute to the increased productivity of today's seed offerings. We also assess various public and private efforts that have both protected genetic diversity while also unlocking hidden genetic secrets that allow crops to perform even in the face of pests, disease and environmental stresses.
Today, in our third story of the series, we share the latest advancements in the battle against soybean cyst nematode, the leading cause of yield loss in soybeans.
OTHER SOURCES OF RESISTANCE
Another source of resistance called Peking is becoming more available in commercial varieties, but it requires a minimum of two genes to have base resistance. Making sure other attributes, such as yield, aren't compromised in the breeding process becomes more complicated, Pruski notes.
BASF is currently developing a Bt trait, a Cry14Ab protein, as the first genetically modified solution for nematode control. The nematode-resistant soybean (NRS) will be stacked with PI88788 initially. Pruski said BASF also hopes to have a Peking option available.
"Five years of internal field trials within our trait development group indicate there's an 8% yield improvement over today's SCN resistant varieties," Pruski said. Last year, the company evaluated 30,000 Enlist E3/NRS lines, and slightly more than 4,000 made it to 2023 yield trial testing. The NRS lines are expected in commercial lineups by end of decade, pending regulatory approvals.
BASF has entered into trait licensing agreements with other leading soybean-breeding companies to ensure that varieties will be broadly available with the NRS trait in a stack with Enlist E3.
Links to recent SCN articles:
"Free Calculator Figures Soybean Cyst Nematode Cost," at https://www.dtnpf.com/…
"Catch Soybean Cyst in the Act," https://www.dtnpf.com/…
See related Editors' Notebook blog about the series, "The Power of 'Magic Beans,'" at https://www.dtnpf.com/…
To see other stories in the Seed Solutions series:
Seed Solutions - 1, "National Seed Bank Provides Future Security," at https://www.dtnpf.com/…
Seed Solutions - 2, " How Seed Companies Respond to New Corn Threats," at https://www.dtnpf.com/….
Pamela Smith can be reached at email@example.com
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