QTL Mapping Of Wheat Growth And Development And Stem Related Traits

Great troubles of global food production have emerged due to the frequent occurrence of extreme weather.The reduction in available cultivated land makes the problem of food security even more severe.As a food crop on which humans depend for survival,ensuring high yield and stable yield is an important strategy for us to solve food security problems.QTL mapping is an effective way to achieve high yield,stable yield and high quality of wheat by detecting the important QTL locus.In this study,a recombinant lines(RILs)population derived from crosses Xinong 1376 and Xiaoyan 81 was researched.The wheat 50 k gene chip was used to detect the population and to construct the high-density genetic map.QTL mapping was performed on the development-related traits and stem-related traits of the population.The main results are as follows:1?In the 50 K chip,a total of 15847 polymorphic markers were screened,and after further removed redundant markers,2524 molecular markers were obtained for constructing the genetic linkage map.The constructed map covered the genetic distance of the wheat genome of 3119.2 cM with an average map distance of 1.2 cM.2?For the development-related traits,a total of 43 QTL loci were identified,distributed in 1A(3),1B(3),2D(2),3B(3),4A(2),4B,4D,5A(8),5B,5D(6),6A(3),6B(2),6D(2),7A(2),7D(4)chromosomes.11 locus controlling heading date,12 locus controlling flowering date,8 locus controlling interval heading stage between two sowing date and 12 locus controlling seedling growth habit are included.A single locus can explain 0.31-78.57% of the phenotypic variance,of which 7 QTLs is the main effect QTL with PVE(phenotypic variance explained)more than 10%,and 15 QTLs can be detected in no less than two environments.3?For the stem-related traits,a total of 45 locus were mapped in this study,which were widely distributed in 1A,1B,2A(8),2B,3A(2),3B(2),3D(3),4B(3),4D(6),5A(4),5B(2),5D(5),6B(5),6D,7A chromosomes,7 locus controlling the first basal internode length,8 locus controlling the second basal internode length,6 locus controlling the first basal stem diameter,2 locus controlling the second basal stem diameter,1 locus controlling the first basal stem wall thickness,3 locus controlling the second basal stem wall thickness,7 locus controlling the first basal stem pith diameter,3 locus controlling the second basal stem pith diameter,and 8 locus controlling the plant height.A single locus can explain 1.23-37.63% of the phenotypic variance,of which 17 QTLs with PVE greater than 10% and 18 QTLs can exist stably in no less than two environments.4?Eight QTL clusters harboring multiple QTL were detected in this study which distributed in 1B,2A,3B,4D,5A,5D(2),and 6D chromosomes.The QTL clusters located on 1B,2A,and 4D are mainly related to stem traits.However,the QTL clusters located on 3B,5A and 5D are both related to developmental stability and stem related traits.Among them,the QTL located on the 5D chromosome between the markers AX-89774282 and AX-110823295 is closely linked to the VRN-D1(vernalization gene)which can regulate all development-related traits involved in this study and some stem related traits(plant height,the length of basal internode)simultaneously.Located on chromosome 2A,the QTL between markers AX-109842248 and AX-108991361 can regulate basal internode stem diameters,basal internode pith diameter and the plant height simultaneously.