QTL mapping of soybean node numbers on the main stem and meta-analysis for mining candidate genes

Abstract

The soybean (Glycine max) node number on the main stem (NNMS) is closely related to seed yield of soybean. The aim of this study was to identify important loci affecting soybean NNMS using meta-analysis based on a reference physical map. Twenty-nine NNMS-related QTLs were mapped across 8 years with a recombination inbred line (RIL) population. Fifty-four QTLs related to NNMS of soybean identified from the database and our research were collected and each QTL was projected onto the soybean physical map. Through meta-analysis, 11 consensus soybean NNMS QTLs were obtained and located on LG D1b, LG C2, LG B1, LG F, LG L, and LG I. The map distance was from 0.02 to 4.22 Mb, the variation of original QTLs was from 2 to 4, and the mean R2 values ranged from 6.90% to 27.40%. Furthermore, 488 candidate genes were located in these consensus QTLs, 6 of which had a relationship with NNMS. These results may help lay a foundation for fine mapping of QTLs/genes related to NNMS that can be used to help breed high-yield soybean cultivars.

Keywords

• QTL mapping
• Soybean node numbers
• Meta-analysis
• Candidate genes