Quantitative trait locus analysis of fatty acid concentrations in maize

Abstract

A study was conducted to determine the number and chromosomal location of quantitative trait loci (QTL) influencing the concentration of five fatty acids in 200 F2S1 lines derived from an Illinois High Oil (IHO) by Illinois Low Oil (Early Maturity) (ILO(EM)) cross. Restriction fragment length polymorphism (RFLP) analysis was performed on the 200 S1 lines and concentrations of palmitic (16:0), stearic (18:0), oleic (18:1), linoleic (18:2), and linolenic (18:3) acids were determined in self-pollinated kernels harvested from plants grown in replicated field trials during 1992 and 1993. A series of 74 cDNA and genomic clones were used and these revealed 80 polymorphic loci spaced, on average, 24 cM apart throughout the maize genome. Analysis of variance detected significant (p < 0.05) associations between several RFLP loci and the concentration of each fatty acid. A total of 15 RFLP loci clustered in 12 chromosomal regions were associated with the concentration of 16:0, 17 loci clustered in 10 regions were associated with the concentration of 18:0, 12 loci clustered in eight regions were associated with the concentration of 18:1 and 18:2, and 17 loci clustered in eight regions were associated with the concentration of 18:3. Multiple linear regression models consisting of four RFLP loci explained 24 and 62% of the total phenotypic and genotypic variation (R2) among the 200 F2S1 lines for 16:0, five loci explained 51 and 71% of the variation for 18:0, three loci explained 67 and 79% of the variation for 18:1, two loci explained 67 and 81% of the variation for 18:2, and seven loci explained 52 and 78% of the variation for 18:3 in these 200 F2S1 lines. The ratio of 18:1 to 18:2 was tightly interrelated as the same QTL were associated with the concentrations of 18:1 and 18:2. A quantitative trait locus that explained 63% of the phenotypic variation in the ratio of 18:1 to 18:2 is tightly linked to umc65 on chromosome 6 in the region of the linoleic acid1 locus.

Targeting of the Arabidopsis Homomeric Acetyl-Coenzyme A Carboxylase to Plastids of Rapeseeds

“…W h e n a11 data are combined, a statistically significant increase is obtained. Furthermore, the increase in 18:l content is consistent with results i n maize, indicating a positive correlation between total seed oil content a n d 18:l percentages (Alrefai et al, 1995).…”

QTL verification of grain protein content and its correlation with oil content by using connected RIL populations of high-oil maize

“…However, more recently, several studies have demonstrated positive correlations between grain protein and oil contents (Dudley and Lambert, 2004;Wassom et al, 2008;Zhang et al, 2008). Further research has attempted to reveal the genetic mechanisms underlying kernel composition traits by mapping QTLs using different genetic germplasms such as IHP and ILP (Goldman et al, l993;, IHO and ILO (Alrefai et al, 1995;Berke and Rocheford, 1995;Laurie et al, 2004;Willmot et al, 2006;Wassom et al, 2008), Beinongda high-oil (BHO) (Song et al, 2004;Zhang et al, 2008), tropical high-oil (Mangolin et al, 2004), Alexho Single-Kernel (ASK) high-oil (Zheng et al, 2008;Li et al, 2009;Wang et al, 2010;Yang et al, 2012), and popcorn (Liu et al, 2008) maize populations. Based on data obtained from these studies and from the public genetic linkage map of maize (www.maizegdb.org), 79 QTLs for grain protein content and 52 QTLs for grain oil content have been detected.…”

Genetic Control of Storage Oil Synthesis in Seeds of Arabidopsis

“…With the advent of molecular markers and the development of quantitative trait loci (QTL) mapping procedures, genes that control storage lipid synthesis can be identified and marker-assisted selection used to move beneficial QTL alleles into elite agricultural genotypes in oilseed breeding programs (Lande and Thompson, 1990). QTL analyses of oil content have been made in a number of crops, including oilseed rape (Brassica napus; Ecke et al, 1995;Burns et al, 2003), soybean (Glycine max; Lee et al, 1996;Csanadi et al, 2001), maize (Zea mays; Alrefai et al, 1995), and sunflower (Helianthus annuus; Mokrani et al, 2002;Leon et al, 2003). An analysis of groat oil content in oats revealed the presence of a small number of QTLs and an association between the major QTL and the plastidic acetyl-CoA carboxylase gene (Kianian et al, 1999).…”

“…In Arabidopsis, mutagenesis experiments facilitated the identification of genes responsible for fatty acid elongation and desaturation (James and Dooner, 1990;Lemieux et al, 1990;Arondel et al, 1993;Okuley et al, 1994;James et al, 1995). Since then, QTL affecting fatty acid composition that colocate with loci for fatty acid elongase and fatty acid desaturase genes have been identified in Brassica species, sunflower, and maize (Alrefai et al, 1995;Ecke et al, 1995;Jourdren et al, 1996;Cheung et al, 1998;Fourmann et al, 1998;Lionneton et al, 2002;Perez-Vich et al, 2002;Burns et al, 2003;Mikkilineni and Rocheford, 2003).…”