Mapping of a QTL for oleic acid concentration in spring turnip rape (Brassica rapa ssp. oleifera)

Abstract

Bulk segregant analysis was used to search for RAPD (random amplified polymorphic DNA) markers linked to gene(s) affecting oleic acid concentration in an F2 population from the Brassica rapa ssp. oleifera cross Jo4002 x a high oleic acid individual from line Jo4072. Eight primers (=8 markers) out of 104 discriminated the 'high' and 'low' bulks consisting of extreme individuals from the oleic acid distribution. These markers were analysed throughout the entire F2 population, and their association with oleic acid was studied using both interval mapping and ANOVA analysis. Six of the markers mapped to one linkage group. A quantitative trait locus (QTL) affecting oleic acid concentration was found to reside within this linkage group with a LOD score >15. The most suitable marker for oleic acid content is OPH-17, a codominant marker close (<4cM) to the QTL. The mean seed oleic acid content in the F2 individuals carrying the larger allele of this marker was 80.14±9.76%; in individuals with the smaller allele, 54.53±6.83%; in the heterozygotes, 65.47±8.15%. To increase reproducibility, the RAPD marker was converted into a SCAR (sequence characterized amplied region) marker with specific primers. Marker OPH-17 can be used to select spring turnip rape individuals with the desired oleic acid content.

Partitioning genetic effects due to embryo, cytoplasm and maternal parent for oil content in oilseed rape (Brassica napus L.)

“…If the seed traits were controlled by the genes of the three genetic systems at the same time then the genetic estimations for seed traits obtained from only one genetic system without excluding the influences of other genetic systems would be biased and might mislead breeders. Recently, quantitative trait locus (QTL) mapping has been conducted on oilseed rape to dissect the effects of individual loci for seed traits in terms of rape-oil yield (Tanhuanpää et al, 1996;Thormann et al, 1996;Zhao et al, 2005). QTL analysis in which the molecular marker near the available locus can be screened is important in molecular breeding strategies such marker associated selection (MAS) used to screen the target materials precisely and improve selection efficiency for quantitative traits (Tanhuanpää et al, 1996;Somers et al, 1998;Gupta et al, 2004).…”

“…Recently, quantitative trait locus (QTL) mapping has been conducted on oilseed rape to dissect the effects of individual loci for seed traits in terms of rape-oil yield (Tanhuanpää et al, 1996;Thormann et al, 1996;Zhao et al, 2005). QTL analysis in which the molecular marker near the available locus can be screened is important in molecular breeding strategies such marker associated selection (MAS) used to screen the target materials precisely and improve selection efficiency for quantitative traits (Tanhuanpää et al, 1996;Somers et al, 1998;Gupta et al, 2004). So far, QTL mapping for seed traits has been based on the maternal plant because of the QTL method used to map agriculturally plant traits.…”

A Systems Genetics Approach Identifies Gene Regulatory Networks Associated with Fatty Acid Composition in Brassica rapa Seed

“…BnaFAE1 is a candidate gene for erucic acid and total oil content in B. napus seed (Peng et al, 2010), while BrFAD3 is a candidate gene for the synthesis of linolenic acid in seed triacylglycerols in B. rapa ssp. oleifera (Tanhuanpää and Schulman, 2002). To our knowledge, this is the first genome-wide genetic study for the FA composition and transcriptional regulation of developing seeds of B. rapa.…”

Mapping QTLs for mineral accumulation and shoot dry biomass under different Zn nutritional conditions in Chinese cabbage (Brassica rapa L. ssp. pekinensis)

“…Furthermore the syntenic relationship with the related genus Arabidopsis is now well established (reviewed by Schranz et al 2006) and allows the comparison of map positions between Brassica and Arabidopsis. For B. rapa QTL analyses have been described for a wide variety of morphological and physiological traits such as seed colour, pubescence, flowering time (Teutonico and Osborn 1994;Song et al 1995;Nozaki et al 1997;Lou et al 2007), oleic acid concentration (Tanhuanpaa et al 1996), linolenic acid content (Tanhuanpaa and Schulman 2002), clubroot resistance (Suwabe et al 2006) and black rot resistance (Sogengas et al 2007). As microspore culture can be applied efficiently in Brassica species, doubled haploid (DH) populations are presently the preferred mapping populations for QTL studies because of their immortality and homozygosity which allows replicated experiments.…”