Identification of candidate genes associated with resistance to Heterodera sojae in soybean

We identified QTLs and candidate genes associated with resistance to Heterodera sojae and then designed KASP markers from candidate genes on chromosomes 1 and 18 for marker-assisted selection. Heterodera sojae is a recently discovered cyst nematode species that parasitizes soybean roots, reducing soybean growth and yield. However, genes associated with resistance to H. sojae in soybean remain unknown. A genome-wide association study of genes related to resistance to H. sojae was performed with a panel of 385 soybean accessions using an Axiom 180 K SoyaSNP array and whole-genome sequencing data. Thirteen significant single-nucleotide polymorphisms (SNPs) were identified; among them, four SNPs located on chromosomes 1 and 18 were selected to identify candidate resistance genes and develop kompetitive allele-specific PCR (KASP) markers for efficient genotyping. Haplotype analysis revealed 16 candidate genes within two haplotype blocks adjacent to the SNPs that were significantly associated with resistance to H. sojae. The functions of these candidate genes were predicted based on the JGI Plant Gene Atlas, which showed that they were specifically expressed in soybean roots. The KASP markers developed based on these SNPs can be used to perform marker-assisted selection in soybean breeding programs to develop soybean cultivars resistant to H. sojae.