|MA, JIANXIN - Purdue University|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/9/2023
Publication Date: 9/13/2023
Citation: Detranaltes, C.E., Ma, J., Cai, G. 2023. Identification of Soybean Germplasm and Associated Molecular Markers with Resistance to Fusarium graminearum. Agronomy Journal. 13. Article 2376. https://doi.org/10.3390/agronomy13092376.
Interpretive Summary: Pre-emergence seed rots and post-emergence seedling decay are among the most serious symptoms caused by soybean seedling diseases. For the past two decades, soybean yield loss due to seedling diseases have consistently ranked as the second highest behind only those caused by soybean cyst nematode. Fusarium graminearum is one of the major pathogens causing seedling disease in soybean. In this study, we screened a set of 208 diverse soybean accessions in maturity groups 0-IV for resistance to this pathogen. Eight accessions were found to be significantly more resistant. A genome-wide association study found five single nucleotide markers associated with resistance. This study identifies valuable new sources of F. graminearum resistance and selection markers that will be critical for breeding new resistance into commercial soybean cultivars.
Technical Abstract: Soybean ranks second by total production of all crops grown in the United States. From surveys of soybean production regions in the US and Canada, seedling diseases have been consistently identified as one of the top 5 biotic limitations on yield for over two decades. The role of Fusarium graminearum as an aggressive member of this complex was unknown until relatively recently, and consequently publicly and commercially available varieties with resistance to this pathogen are unavailable. To address the need for resistant germplasm and to improve our understanding of the genetic basis underlying the resistance, we screened a set of 208 accessions of soybean from the United States Department of Agriculture Soybean Germplasm Collection (USDA-SGC) under controlled greenhouse conditions. A ratio of root weight of inoculated plants compared to mock-inoculated controls was used to evaluate the degree of resistance. A linear mixed model identified eight resistant accessions with significantly higher resistance than the population mean. Previous genotyping publicly available through the SoyBase database was used in a genome-wide association study (GWAS) to determine single nucleotide polymorphism (SNP) markers associated with resistant and susceptible phenotypes. A total of five significant marker-trait associations (MTAs) were discovered on chromosomes Gm02, Gm03, Gm06, Gm07, and Gm13, each accounting for 4.8, 4.3, 3.8, 4.1, and 3.0% of the phenotypic variance, respectively. This study thus lays a foundation for better selection of germplasm resistant to F. graminearum.