Development of Glycine max Germplasm Highly Resistant to Sclerotinia sclerotiorum

Sclerotinia stem rot (SSR) of soybean caused by Sclerotinia sclerotiorum is a devastating disease of soybean, especially in the Upper Midwest region of the United States. To mitigate yield losses due to this disease, many control methods are available for producers, including cultural control practices, chemical control, and cultivars with quantitative resistance. However, due to there being few commercial cultivars with high levels of resistance, producers are often limited in their seed selection. The aim of this study was to develop novel conventional soybean cultivars with high levels of resistance to SSR, favorable agronomic traits, and resistance to additional economically important diseases. Initial crosses were conducted in 2016 with two different sources of SSR resistance. Across multiple generations of screening for resistance to SSR, three highly resistant soybean lines were identified as the elite lines. These elite lines were demonstrated to be highly resistant across multiple years in both greenhouse and field trials, including high levels of resistance to multiple diverse S. sclerotiorum isolates. The three selected elite lines also resulted in moderately high yields and favorable agronomic traits, such as low lodging and moderate branching, indicating their viability to be released for production. In addition to SSR resistance, these three elite lines demonstrated resistance to other economically important soybean diseases, such as frogeye leaf spot, anthracnose, Cercospora leaf blight, and brown stem rot. Overall, this work has led to three SSR-resistant soybean lines that could be useful for future breeding efforts or commercial soybean production.This article is published as Webster, Richard Wade, Megan McCaghey, Brian Mueller, Carol Groves, Febina Merlin Mathew, Asheesh Singh, Mehdi Kabbage, and Damon L. Smith. "Development of Glycine max Germplasm Highly Resistant to Sclerotinia sclerotiorum." PhytoFrontiers (2023). doi:10.1094/PHYTOFR-01-23-0009-R. Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license