QTL Analysis Of The Grain Morphologic Traits And Micronutrient Content Of Wheat (Triticum Aestivum L.) Under Different Environments

Wheat yield and quality are very important for the grain production, as the second-largest crop worldwide. Wheat grain qualities include morphologic quality, nutritional quality and processing quality. For the morphologic quality, peasant prefer sowing big size to small size grain. For nutritional quality, people not only want to eat one's fill but also want to eat one's well along with the standard of living improved, so they pay more attention to grain micronutrition than ever.In order to improve wheat breeding level and study the genetic mechanism of kernel morphologic and micro-nutritional qualities, such as kernel shape, weight, crude fiber, micro-nutritional minerals as well as fatty acid, quantitative trait locus (QTL) analysis was conducted in common wheat using a set of 131 recombinant inbred lines (RIL) derived from'Chuan 35050'×'Shannong 483'(ChSh population). The mian results are as follows.1) QTL analysis of kernel shape and weight Quantitative trait locus (QTL) analysis of kernel shape and weight in common wheat was conducted using ChSh population. The RIL and their two parental genotypes were evaluated for kernel length (KL), kernel width (KW), thousand-kernel weight (TKW), and test weight (TW) in four different environments. Twenty QTL were located on 12 chromosomes, 1A, 1B, 1D, 2A, 2B, 3B, 4A, 4B, 5D, 6A, 6B, and 7B, with single QTL in different environments explaining 5.9–26.4% of the phenotypic variation. Six, three, four, and seven QTL were detected for KL, KW, TKW, and TW, respectively. The additive effects for 17 QTL were positive with Chuan 35050 increasing the QTL effects, whereas the remaining three QTL were negative with Shannong 483 increasing the effects. Eight QTL (40%) were detected in two or more environments. Two QTL clusters relating to KW, TKW, and TW were located on chromosomes 2A and 5D, and the co-located QTL on chromosome 6A involved a QTL for KW found in two environments and a QTL for TKW detected in four environments.2) QTL analysis of wheat quality tested by NIR QTL mapping of wheat quality traits tested by near-infrared reflectance (NIR) in common wheat were conducted using ChSh population. The RILs were evaluated for grain protein content (GPC), grain starch content (GSC), grain crude fibre content (GCFC) and grain hardness (GH) in six environments. A total of 38 QTLs were located on 16 chromosomes with a single QTL explaining 4.2-73.7% phenotypic variation in different environments. Nine, five, fourteen, thirteen and ten QTLs for GPC, GSC, GCFC and GH were detected. Thirteen QTLs (34.2%) were detected in two or more environments. Four co-located QTLs between two traits occurred on chromosomes 1B, 2D, 4B and 5D, and two QTL clusters related to three traits were located on chromosomes 1B and 1D. QGpc.sdau-4A were located in a 5.9-cM marker region of Xissr23b-Xwmc308- Xsrap7c with the highest contributions; and the contributions of QGh.sdau-1D.2 were 37.1, 38.9 and 29.7% in HZ07, HZ08 and YT07, respectively, suggesting that these two QTLs were major QTLs.3) QTL analysis of grain elemnt concent QTL mapping for grain elemnt content tested by ICPOES (inductively couples plasma optical emission spectrometry) in common wheat were conducted using ChSh population. The RILs were evaluated for nine type of elemnt concentration including P, K, Mg, S, Ca, Mn, Fe, Cu and Zn in five environments. A total of 38 QTLs were located on 13 chromosomes with a single QTL explaining 5.9-81.68% phenotypic variation in different environments. Five, three, four, four, six, nine, four, one and three QTLs for P, K, Mg, S, Ca, Mn, Fe, Cu and Zn content were detected. Only five QTLs were detected in two environments. Six co-located QTLs between two traits occurred on chromosomes 1B, 3B, 3D, 4A, 6A and 7A, and four QTL clusters related to different traits were located on chromosomes 1D, 3D, 4A and 7A. The result maybe implye that the grain element content are affected by different environment, and that there is a linkage relation among the QTLs about grain element content.4) QTL analysis of wheat fatty acid QTL mapping for grain fatty acid content tested by Gas Chromatography in common wheat were conducted using ChSh population. The RILs were evaluated for five type of fatty content including almitic acid (C16:0), Stearic acid (C18:0), Oleic acid (C18:1), Linoleic acid (C18:2) and Linolenic acid in five environments. A total of 35 QTLs were located on 13 chromosomes with a single QTL explaining 3.85-43.73% phenotypic variations in different environments. Seven, ten, nine, five and four QTLs for almitic acid, Stearic acid, Oleic acid, Linoleic acid and Linolenic acid concent were detected, respectively. Only five QTLs were detected in two environments. Six co-located QTLs between two traits occurred on chromosomes 1A, 2A, 3B, 4A, 5A and 7B, and only one QTL clusters related to different traits were located on chromosomes5D. The results maybe suggest that there is a linkage relation among the QTLs relating to grain fatty content,and these are in accordance with the correlation coefficients.