Mapping of Two Major QTLs Controlling Flowering Time in Brassica napus Using a High-Density Genetic Map

Molecular mapping and candidate gene identification of two major quantitative trait loci associated with silique length in oilseed rape (Brassica napus L.)

Rapeseed is a significant global source of plant oil. Silique size, particularly silique length (SL), impacts rapeseed yield. SL is a typical quantitative trait controlled by multiple genes. In our previous study, we constructed a DH population of 178 families known as the 158A-SGDH population. In this study, through SL QTL mapping, we identified twenty-six QTL for SL across five replicates in two environments. A QTL meta-analysis revealed eight consensus QTL, including two major QTL: cqSL.A02-1 (11.32-16.44% of PVE for SL), and cqSL.C06-1 (10.90-11.95% of PVE for SL). Based on biparental resequencing data and microcollinearity analysis of target regions in Brassica napus and Arabidopsis, we identified 11 candidate genes at cqSL.A02-1 and 6 candidate genes at cqSL.C06-1, which are potentially associated with silique development. Furthermore, transcriptome analysis of silique valves from both parents on the 14th, 21st, and 28th days after pollination (DAP) combined with gene function annotation revealed three significantly differentially expressed genes at cqSL.A02-1, BnaA02G0058500ZS, BnaA02G0060100ZS, and BnaA02G0060900ZS. Only the gene BnaC06G0283800ZS showed significant differences in parental transcription at cqSL.C06-1. Two tightly linked insertion-deletion markers for the cqSL.A02-1 and cqSL.C06-1 loci were developed. Using these two QTL, we generated four combinations: A02SGDH284C06158A, A02SGDH284C06SGDH284, A02158AC06158A, and A02158AC06SGDH284. Subsequent analysis identified an ideal QTL combination, A02158AC06SGDH284, which exhibited the longest SL of this type, reaching 6.06 ± 0.10 cm, significantly surpassing the other three combinations. The results will provide the basis for the cloning of SL-related genes of rapeseed, along with the development of functional markers of target genes and the breeding of rapeseed varieties.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11032-024-01464-x.

Brassica napus Haploid and Double Haploid Production and Its Latest Applications

Rapeseed is one of the most important oil crops in the world. Increasing demand for oil and limited agronomic capabilities of present-day rapeseed result in the need for rapid development of new, superior cultivars. Double haploid (DH) technology is a fast and convenient approach in plant breeding as well as genetic research. Brassica napus is considered a model species for DH production based on microspore embryogenesis; however, the molecular mechanisms underlying microspore reprogramming are still vague. It is known that morphological changes are accompanied by gene and protein expression patterns, alongside carbohydrate and lipid metabolism. Novel, more efficient methods for DH rapeseed production have been reported. This review covers new findings and advances in Brassica napus DH production as well as the latest reports related to agronomically important traits in molecular studies employing the double haploid rapeseed lines.