QTL Mapping by Chromosome Segment Substitution Lines (CSSLs) Reveals Candidate Gene Controlling Leaf Sucrose Content in Soybean (Glycine max (L.) Merr.)

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.