Quantitative Trait Locus Mapping Combined with RNA Sequencing Reveals the Molecular Basis of Seed Germination in Oilseed Rape

Abstract

Rapid and uniform seed germination improves mechanized oilseed rape production in modern agricultural cultivation practices. However, the molecular basis of seed germination is still unclear in Brassica napus. A population of recombined inbred lines of B. napus from a cross between the lower germination rate variety ‘APL01’ and the higher germination rate variety ‘Holly’ was used to study the genetics of seed germination using quantitative trait locus (QTL) mapping. A total of five QTLs for germination energy (GE) and six QTLs for germination percentage (GP) were detected across three seed lots, respectively. In addition, six epistatic interactions between the QTLs for GE and nine epistatic interactions between the QTLs for GP were detected. qGE.C3 for GE and qGP.C3 for GP were co-mapped to the 28.5–30.5 cM interval on C3, which was considered to be a novel major QTL regulating seed germination. Transcriptome analysis revealed that the differences in sugar, protein, lipid, amino acid, and DNA metabolism and the TCA cycle, electron transfer, and signal transduction potentially determined the higher germination rate of ‘Holly’ seeds. These results contribute to our knowledge about the molecular basis of seed germination in rapeseed.

Detection of closely linked QTLs and candidate genes controlling germination indices in response to drought and salinity stresses in barley

“…From a genetic viewpoint, the process of seed germination is influenced by complex interactions like plant hormone signal transductions. In a study, it was suggested that signal transduction is essential for seed germination in Brassica napus 27 . Moreover, it was reported that the signal transduction system is very important for asparagus bean in protecting itself from salinity 28 .…”

Exploration into Natural Variation Genes Associated with Determinate and Capitulum-like Inflorescence in Brassica napus

“…Combining the traditional BSA method and the next-generation sequencing (NGS) technique, the BSA-Seq technique has been widely used in QTL mapping for the precise identification of target genes [ 25 , 26 , 27 ], such as in rapeseed [ 28 ], rice [ 27 ], maize [ 29 ], and so on. Furthermore, the combined analysis of BSA-seq and RNA-seq data enabled the identification of candidate genes [ 30 , 31 , 32 ].…”