Abstract
High-density linkage maps can improve the precision of QTL localization. A high-density SNP-based linkage map containing 3207 markers covering 3072.7 cM of the Brassica napus genome was constructed in the KenC-8 × N53-2 (KNDH) population. A total of 67 and 38 QTLs for seed oil and protein content were identified with an average confidence interval of 5.26 and 4.38 cM, which could explain up to 22.24% and 27.48% of the phenotypic variation, respectively. Thirty-eight associated genomic regions from BSA overlapped with and/or narrowed the SOC-QTLs, further confirming the QTL mapping results based on the high-density linkage map. Potential candidates related to acyl-lipid and seed storage underlying SOC and SPC, respectively, were identified and analyzed, among which six were checked and showed expression differences between the two parents during different embryonic developmental periods. A large primary carbohydrate pathway based on potential candidates underlying SOC- and SPC-QTLs, and interaction networks based on potential candidates underlying SOC-QTLs, was constructed to dissect the complex mechanism based on metabolic and gene regulatory features, respectively. Accurate QTL mapping and potential candidates identified based on high-density linkage map and BSA analyses provide new insights into the complex genetic mechanism of oil and protein accumulation in the seeds of rapeseed.
Highlights
Linkage group A01 A02 A03 A04 A05 A06 A07 A08 A09 A10 C01 C02 C03 C04 C05 C06 C07 C08 C09 A genome C genome Total (A +C)
QTL studies have led to the identification of numerous loci that are responsible for variation in seed oil content (SOC) and seed protein content (SPC), but the corresponding genomic regions with their complex metabolism and regulatory mechanisms have not been studied with great accuracy
A. thaliana acyl-lipid and storage protein-related orthologous genes mapped in a confidence interval (CI) of QTLs on the B. napus genome might be valuable to identify the candidate genes and dissect the complex metabolism and regulatory mechanism associated with SOC and SPC
Summary
Linkage group A01 A02 A03 A04 A05 A06 A07 A08 A09 A10 C01 C02 C03 C04 C05 C06 C07 C08 C09 A genome C genome Total (A +C). A. thaliana acyl-lipid and storage protein-related orthologous genes mapped in a confidence interval (CI) of QTLs on the B. napus genome might be valuable to identify the candidate genes and dissect the complex metabolism and regulatory mechanism associated with SOC and SPC. This present report consists of the following three parts: (1) the construction of a high-density genetic linkage map based upon SNP markers combined with non-SNP (SSR and STS) markers that have been used previously to generate a primary linkage map in the KenC-8 ×N53-2 (KNDH) population[39]; (2) precise QTL mapping of SOC and SPC across multiple environments based on a high-density genetic linkage map and rapid detection of associated genomic regions (AGRs) using BSA; (3) identification of candidate genes within QTL regions and provision of primary insights into the complex metabolism and regulatory mechanism of SOC and SPC in B. napus
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have