Quantitative Trait Loci for Biofortification Traits in Maize Grain

Abstract

Detecting genes that influence biofortification traits in cereal grain could help increase the concentrations of bioavailable mineral elements in crops to solve the global mineral malnutrition problem. The aims of this study were to detect the quantitative trait loci (QTLs) for phosphorus (P), iron (Fe), zinc (Zn), and magnesium (Mg) concentrations in maize grain in a mapping population, as well as QTLs for bioavailable Fe, Zn, and Mg, by precalculating their respective ratios with P. Elemental analysis of grain samples was done by coupled plasma-optical emission spectrometry in 294 F(4) lines of a biparental population taken from field trials of over 3 years. The population was mapped using sets of 121 polymorphic markers. QTL analysis revealed 32 significant QTLs detected for 7 traits, of which some were colocalized. The Additive-dominant model revealed highly significant additive effects, suggesting that biofortification traits in maize are generally controlled by numerous small-effect QTLs. Three QTLs for Fe/P, Zn/P, and Mg/P were colocalized on chromosome 3, coinciding with simple sequence repeats marker bnlg1456, which resides in close proximity to previously identified phytase genes (ZM phys1 and phys2). Thus, we recommend the ratios as bioavailability traits in biofortification research.

Participatory Plant Quality Breeding: An Ancient Art Revisited by Knowledge Sharing. The Portuguese Experience

“…Marker-assisted selection is a powerful tool for the indirect selection of difficult traits at an early stage, before production of the next generation, thus speeding up the process of conventional plant breeding and facilitating the improvement of traits that cannot be improved easily by conventional methods (reviewed by [67]). The identification and location of genes controlling quantitative traits through Quantitative Trait Loci (QTL) analysis has already been successful undertaken on maize nutritional quality [68,69,70].…”

Comprehensive phenotypic analysis and quantitative trait locus identification for grain mineral concentration, content, and yield in maize (Zea mays L.)

“…Quantitative trait locus (QTL) mapping is a powerful approach to study and manipulate complex traits important in agriculture (Abiola et al 2003). A wide range of genetic variation for grain mineral accumulation has been revealed among maize accessions, suggesting that traits of mineral accumulation are complex quantitative traits (Šimic et al 2012;Qin et al 2012;Baxter et al 2013). Therefore, QTL analysis could greatly accelerate genetic modification of mineral amount in maize grain by marker-assisted selection (MAS) and even discovery of underlying candidate genes.…”

“…Several QTL studies have been conducted in maize for grain mineral concentration (Garcia-Oliveira et al 2009;Zhou et al 2010;Lung'aho et al 2011;Qin et al 2012;Šimic et al 2012;Baxter et al 2013Baxter et al , 2014. Stable or consistent QTL across different environments could only be identified in some of these above studies.…”

Identification of quantitative trait loci for mineral elements in grains and grass powder of barley

“…Significant additive genetic effects as well as parental mean effects have previously been detected for P, K, Ca, and Na (Fernandes Santos and Boiteux, 2015). Co-localization of QTLs for element concentration has previously been found in various species, such as rice (Yu et al, 2015) and in maize grain (Simić et al, 2012). Co-localization of QTLs for the qP3/qMg3/qZn3 region was shown to have the largest effects for P, Mg, and Zn contents, whereas the qK6.1/qCa6/qZn6/qMn6/qCu6 region was found to be responsible for five of seven mineral elements in milled rice in RIL populations (Yu et al, 2015).…”

“…Co-localization of QTLs for the qP3/qMg3/qZn3 region was shown to have the largest effects for P, Mg, and Zn contents, whereas the qK6.1/qCa6/qZn6/qMn6/qCu6 region was found to be responsible for five of seven mineral elements in milled rice in RIL populations (Yu et al, 2015). Three QTLs for Fe/P, Zn/P, and Mg/P were co-localized on chromosome 3 in maize, coinciding with the SSR marker bnlg1456 (Simić et al, 2012). Co-localization of QTLs for functional components has been previously found in functional rice, including resistant starch and total alkaloid content in both brown and polished rice (Zeng et al, 2016a).…”