University of Nebraska-Lincoln Norborne, Missouri, United States
Abstract Text: Soybean cyst nematode (Heterodera glycines, SCN) is the most yield-limiting pathogen of soybeans in the United States. SCN can cause significant yield loss without noticeable aboveground symptoms. It has been detected in 60 Nebraska counties, where management relies primarily on the rotation of resistant soybean varieties. SCN virulence (HG Type) has evolved over time, reducing the effectiveness of overused resistance sources. This study aims to analyze 150 soil samples collected from Nebraska soybean fields in 2021, 2022, and 2023. Knowing which SCN HG types are most common will help understand why resistance declines and how to breed better soybeans in the future. The second component of the study involves molecular analysis to help assess the genotypic diversity of SCN populations across Nebraska. To date, one-third of the study has been completed using 50 samples, revealing a higher reproduction rate of SCN on the two most used resistance sources. Molecular analysis identified two haplotype groups among 46 SCN populations, indicating low genetic diversity within Nebraska SCN populations. This research will enhance understanding of SCN population behavior and support the development of improved management strategies for sustainable soybean production.
