QTL Mapping For Several Agronomic And Quality-related Traits Of Wheat

Wheat(Triticum aestivum L.)is one of the most important cereal crop in the world.Common wheat is a heterohexaploid(2n = 6x = 42)and contains three chromosome groups A,B and D,so the genome information is very large.Because of the widespread existence of its repeated sequences in the genome,the molecular research of wheat lags behind rice,corn and other crops.Many agronomic traits of wheat,such as yield and quality mostly belong to quantitative traits and the phenotypic value is the result of the interaction between genes and environment.Therefore,QTL mapping for important agronomic and quality traits of wheat is significant for molecular marker-assisted selection breeding and improving breeding efficiency.In this study,a RIL population with 164 lines,derived from the cross of Shannong33 and AVS,was analyzed by wheat 55 K SNP genotyping chips technology.The genetic linkage map was constructed.The plant height,spike length,Top internode length and quality traits of wheat were mapped by QTL.The main findings are as follows:1.We were carried out RIL population in plant height,spike length,top first internode length and quality traits in two years and three point,The results of plant height,spike length,top first internode length and quality traits showed significant different among parents,Traits skewness coefficient and group kurtosis coefficient of RIL populations are less than l,displays normal distribution.It indicated that the alleles control seeds shape randomly di stributed on the parents' chrosomes.2.A total of 34 QTLs related to plant height,ear length,and Top internode length were detected in three different environments,which is located on16 chromosomes 1B,2B,2D,3A,3B,3D,4B,4D,5A,5B,5D,6A,6B,6D,7A and 7D,including 14 QTLs controlling plant height(PVE: 3.47%-18.87%),12 spikes(PVE: 0.64%-30.13%),and 8 lower nodes(PVE: 3.95%-16.21%).there are 9 major QTLs and 25 minor QTLs among these 34 QTLs.3.A total of 47 QTLs controlling quality-related traits were detected in three different environments,located on chromosomes 1A,1B,1D,2B,2D,3A,3B,3D,4A,5A,5B,5D,6A,6B,7A and 7B.The maximum number of QTLs controlling the maximum extension resistance is 7,the sedimentation value is 6,and the water absorption is only 1;25 of these QTLs can explain phenotypic variation greater than 10%,and 22 QTLs can explain 5 %-10% phenotypic variation.4.Qph4B(plant height),Qsl2D(spike lenght),Qtfil4B(Top internode length),Qgpc2B(grain protein content)and QSv2B(sedimentation value)can be detected in two environments,which explain over 10% of the phenotypic variations,belong to the stable major QTL.