Co-location of seed oil content, seed hull content and seed coat color QTL in three different environments in Brassica napus L.

Abstract

Increasing seed oil content is an important breeding goal for Brassica napus L. (B. napus). The identification of quantitative trait loci (QTL) for seed oil content and related traits is important for efficient selection of B. napus cultivars with high seed oil content. To get better knowledge on these traits, a molecular marker linkage map for B. napus was constructed with a recombinant inbred lines (RIL) population. The length of the map was 1,589 cM with 451 markers distributed over 25 linkage groups. QTL for seed oil content, seed hull content and seed coat color in three environments were detected by composite interval mapping (CIM) tests. Eleven QTL accounted for 5.19-13.57% of the variation for seed oil content. Twelve QTL associated with seed hull content were identified with contribution ranging from 5.80 to 22.71% and four QTL for seed coat color accounted for 5.23-15.99% of the variation. It is very interesting to found that co-localization between QTL for the three traits were found on N8. These results indicated the possibility to combine favorable alleles at different QTL to increase seed oil content, as well as to combine information about the relationship between seed oil content and other traits.

Identification of QTL for seed coat colour and oil content inBrassica napusby association mapping using SSR markers

“…Allelic data from a total of 389 SSR markers that had been mapped on two linkage maps of RIL populations Yan et al 2009b), and were used for structure analysis of the 217 rapeseed genotypes. These data were used in a genomewide approach to identify markers linked to seed coat colour and oil content.…”

“…A second set of 46 primer pairs with loci in the region of quality traits QTL such seed colour and oil content in our two B. napus RIL populations Yan et al 2009b) were used for targeted association mapping of the two traits.…”

“…Additionally, the inheritance of these traits is complicated and involves multiple gene loci, and the traits are influenced by environmental factors (Shirzadegan 1986;Van Deynze et al 1995). However, a number of studies have detected a major QTL for seed colour on chromosome A9 (Liu et al 2005bBadani et al 2006;Fu et al 2007;Xiao et al 2007;Yan et al 2009b;Zhang et al 2011). Meanwhile, many molecular markers linked to related genes for seed colour have also been identified, for example, the TT10 was considered as the candidate gene, according to the microsynteny of this QTL with Arabidopsis genome sequences , and the findings showed that BnTT10 functions in proanthocyanidin polymerization and lignin biosynthesis, as well as seed coat pigmentation in B. napus .…”

“…These works showed that seed oil content is quantitative in nature and controlled by multiple genes termed quantitative trait loci (QTL), found in almost all the 19 linkage groups, and the trait is affected by environment (G )E) (Burns et al 2003;Zhao et al 2005Zhao et al , 2006Delourme et al 2006;Qiu et al 2006;Amar et al 2008;Yan et al 2009b;Chen et al 2010Chen et al , 2013Sun et al 2012). Moreover, a QTL associated with oil content located in the linkage group 1 (A1) near the public SSR markers BRAS041 or BRAS078 of B. napus has been frequently reported (Zhao et al 2005(Zhao et al , 2012Delourme et al 2006;Qiu et al 2006;Chen et al 2013;Jiang et al 2014), and we also found CB10369 and BRAS041 were mapped to the adjacent regions.…”

“…Therefore, detecting the loci that control these complex traits by quantitative trait locus (QTL) mapping will pave the way for markerassisted selection. QTL mapping studies have been performed in B. napus, for characteristics such as seed coat colour (Liu et al 2005bBadani et al 2006;Fu et al 2007;Xiao et al 2007;Yan et al 2009b;Zhang et al 2011), oil content (Zhao et al 2005(Zhao et al , 2006Delourme et al 2006;Qiu et al 2006). However, conventional QTL mapping efforts using the segregating progeny of a biparental cross allow for the detection of only a subset of loci/alleles within the crop and offer limited resolution, due to the small number of informative recombination events between linked genetic loci.…”