Active accumulated temperature (AAT) serves as a pivotal metric for assessing soybean adaptation across diverse climatic conditions, particularly in the northeastern regions of China. This study embarked on a genome-wide association analysis (GWAS) to elucidate the genetic determinants influencing AAT and its impact on flowering time among soybean varieties. Leveraging a panel of 140 elite soybean varieties encompassing both Chinese and European early-maturity groups and employing high-density genotyping, significant associations were identified on chromosome 6. Notably, a key gene, Glyma.06g204500, emerged as a central component, exhibiting strong linkage to the well-established E1 locus, alongside three distinct haplotypes. This investigation underscores Glyma.06g204500’s potential role in mediating soybean’s response to temperature fluctuations, offering novel insights into the genetic mechanisms underpinning soybean adaptation to local environmental conditions.

Genetic adaptation of soybean phenological stages to high‐latitude long‐day environments is the major pre‐requisite for enhancing regional plant‐based protein production. Both E‐genes controlling flowering and growing environment determine timing of flowering and maturity, and E‐gene composition might differ between Chinese and European soybeans bearing the potential for improving adaptability. Therefore, 140 early maturity elite soybean cultivars of either Chinese or European origin were genotyped for the E1 to E4 flowering loci, and genotypes were tested across 17 European environments spanning a latitude range from 45 to 52°N in order to determine effects of various E‐allele combinations. Differences in E‐allele composition between Chinese and European cultivars were largest for the loci E1 and E3. Wild‐type alleles significantly delayed flowering, and effects of particular E‐alleles were depending on geographic latitude. Consequently, photoperiod‐insensitive E‐haplotypes carrying several non‐functional alleles proved to be suitable for cultivation in higher latitudes, whereas photoperiod‐sensitive late‐maturity E‐haplotypes are adapted to lower latitudes only. Thus, breeding for new E‐haplotypes through combining Chinese and European alleles could enhance the potential for further soybean adaptation to northern growing regions.

Soybean (Glycine max [L.] Merr.) seed hardness is a critical physical trait that dictates processing efficiency and end-product quality, yet the underlying genetic and metabolic regulatory networks remain poorly elucidated. To systematically decipher the mechanisms governing this complex quantitative trait, a multi-omics approach integrating a genome-wide association study (GWAS), transcriptomics, and metabolomics was conducted on a panel of 162 soybean germplasm accessions from Northeast China. Four significant quantitative trait nucleotides (QTNs) on chromosomes 15 and 19 were identified by GWAS. Subsequent RNA-seq and liquid chromatography–mass spectrometry (LC-MS) analyses comparing extreme phenotypes identified 573 differentially expressed genes (DEGs) and 784 differentially accumulated metabolites (DAMs). Joint multi-omics analysis revealed 14 consistently enriched pathways, highlighting the crucial role of secondary metabolite biosynthesis. Notably, Glyma.19G030500, which encodes an isoflavone malonyltransferase, was identified as the primary hub gene. These findings offer valuable genomic targets for the marker-assisted breeding of soybean varieties with optimized processing qualities.

Understanding the genetic basis of leaf sucrose content can provide a novel way in improving soybean yields. To identify the related QTLs, 190 materials of chromosome fragment substitution lines (CSSLs) were used in this study. The CSSLs were developed from the cross between the cultivated soybean Suinong 14 (SN14) and wild soybean ZYD00006. Only one QTL with a high logarithm of odds (LOD) score was detected in 2021 and 2022 among 3780 bin markers (combined by 580,524 SNPs) distributed in 20 chromosomes. Nine candidate genes were screened and Glyma.14G029100 was considered as the hub gene. A promoter difference and CDS mutant was found among the parents and the reference genome, which lead to the relative transcriptional level difference.. Our results lay the groundwork for further research into its genetic mechanism.