Quantitative Trait Loci Mapping And Correlation Analysis On Grain Phytate Concntration In Durum Wheat × Wild Emmer Wheat RILs Population

A tetraploid wheat population consisting of 152 Recombination Inbred Lines(RILs) derived from a cross between Triticum dicoccoides(G18-16) and durum wheat cultivar(Langdon) were planted in four distinct environments with different treatments in this study. The genetic and physiological basis of grain phytate and six component nutrients concentrations were studied for QTL analysis. The correlation network was constructed between the parameters of grain phytate and other 26 traits of component nutrient, mineral elements, and agronomy. The results showed that:1. A total of six QTL effects associated with grain phytate concentration(PHY) were detected in the RILs population planted in four environments, e.g. 2005 Dry, 2005 Wet, 2007 Wet and 2014 GZ over three years. Higher PHY was conferred by the G18-16 allele at four loci(1B, 2A, 2B, 6B) and by the LDN allele at two loci(2B, 2). The identified QTLs located on chromosomes 2A and 6B which near the SSR marker was Xgwm1054 and Xgwm768, respectively under 2005 Dry, 2005 Wet, 2007 Wet environments together, with a LOD score range of ca. 3.1 and 3.9, explaining phenotypic variation range of 4% to 11.9%. Eight extreme PHY RILs were selected to further studies. The highest lines were WR-79, WR-136, WR-162, and WR-187, while WR-4, WR-40, WR-87 and WR-161 were the lowest lines.2. Total of 58 nutrient QTLs, which were total soluble protein(TSP), amino groups(NH2), total phenolics(TP), total flavonoids(TF), inorganic phosphorus(Pi) and yellow pigment content(YPC), were mapped on 14 chromsomes, with a LOD score range of ca. 2.03 ~ 11.08, explaining phenotypic variation range of 2.04 % ~ 54.7 %(2 QTLs). There were the QTLs of 9 TSP, 4 NH2, 16 TP, 7 TF, 12 Pi and 4 YPC. Comparing with the previous studies, some of the QTLs were same or similar, while some of the QTLs were newly mapped.3. The variations of the grain phytate and multicomponent nutritional cocentrations in the RILs population in the four environments were tested in the study. The results showed that PHY had significant difference(P<0.001) among the four environments. PHY under irrigation condition was significantly lower than that under drought condition. The six multicomponent nutritional concentrations, except yellow pigment and total flavonoids concentrations of RILs in the four environments were significantly differences.4. The network analysis of grain phytate and other 26 traits of component nutrient, mineral elements, and agronomy showed that there were positive correlations between grain phytate and total soluble protein, amino, inorganic phosphorus and total phosphorus, respectively. Also, there were co-located QTL effects of the QTLs of these traits. These correlations and the special heredity between phytate and the four nutrients indicated cooperativity in metabolism. Moreover, abundant significant correlations between six nutrients and other 26 traits in the RILs population were found.The huge potential of genetic resources for grain phytate and some component nutrients concentrations in the wild emmer wheat and durum wheat cultivar was demonstrated by the results obtained in the current study. The identified QTLs could be used to the future marker-assisted selection programs, facilitating the use of wild alleles for yield enhancement in elite wheat cultivars. Also, it provides an insight into the functional basis of the physiology, genomic architecture and evolution of useful component nutrients acculmulation in wheat grain under different environments.