Detection of Candidate Loci and Genes Related to Phosphorus Efficiency at Maturity through a Genome-Wide Association Study in Soybean

Abstract

Phosphorus (P) deficiency is one of the major factors limiting soybean production, and approximately 90% of P absorbed by plants occurs during the reproductive stage. Thus, it is important to understand the genetic mechanism underlying soybean low-P tolerance, especially in the mature period. Here, we evaluated six P-efficiency-related traits at maturity of 219 soybean accessions, namely, plant height (PH), node number of the main shoot (NN), branch number of the main shoot (BN), pod number per plant (PN), 100-seed weight (100SW), and seed yield per plant (SY), under normal-phosphorus (NP) and low-phosphorus (LP) conditions across two environments. Then, a genome-wide association study (GWAS) in conjunction with a high-density NJAU 355 K SoySNP array was performed. As a result, 27 P-efficiency-related single nucleotide polymorphisms (SNPs) were identified. Furthermore, two repeated SNPs, AX-93897192 and AX-93897200, located on chromosome 19 that were associated with both PH and NN were considered as stable SNPs associated with P deficiency, and the candidate gene GmABCG39 was identified. This work will be helpful in breeding high-P-efficiency soybean varieties.