Development of new molecular markers and quantitative trait loci for oil content of Brassica napus L.

Abstract

Brassica napus L. from Brassicaceae consisting AACC genome is one of the most important oil crops that contributes to the Canadian economy. The oil produced by B. napus can be made into high profit oil-related products such as cooking oil and machinery lubricant, and it can be classified as either rapeseed or canola depending on the amount of erucic acid and glucosinolates in the seed. Numerous studies on mapping quantitative trait loci (QTL) associated with the seed oil content (SOC) in B. napus have been conducted. Studies have identifed the location of oil-related genes such as BnFAE genes located on chromosomes A8 and C3 which are responsible for the production of erucic acid in the seed. One doubled haploid (DH) population ZT (Topas x Zhongyou821) consisting of 94 DH genotypes was used to collect SOC data in field experiments and under controlled environmental conditions in the greenhouse. A new molecular marker detection method that includes PCR-based sequencing library preparation and Illumina sequencing detection (PISD) was used to identify single nucleotide polymorphisms (SNPs). Two genetic maps, named PISD and combined (standard genotyping-by-sequencing, GBS), were created and 1,092 and 1,821 SNPs molecular markers were used to identify QTL for SOC in the B. napus DH ZT genotypes. In total, six and 8 major QTL were identified using the two genetic maps respectively. In addition, QTL for SOC on chromosomes A8 and C3 were identified as being closely linked to BnFAE1.1 and BnFAE1.2, which are responsible for the production of erucic acid. These results show a better understanding of gene control and can be useful for B. napus breeding industries for erucic acid content in the future.