QTL Analysis For Salinity Tolerance Of Wheat Somatic Hybrid Introgression Line Shanrong No.3 Based On SNP Array

Common wheat(Triticum aestivum L.) is one of the staple crops in china, and plays an important role in agricultural production. Soil salinization has become one of the main barriers to agriculture, which seriously affect the yield and quality of crops. Salt tolerance is a complex quantitative trait controlled by multiple genes in wheat, which affected by environment easily. In recent years, the development of high throughput SNP chip technology has brought new impetus to the reseach of constructing genetic linkage map and working on QTL positioning.A lot of work is being carried out on QTLposition of many important traits in crops.We previously bred a wheat introgression cultivar SR3, which was selected from the hybrids between the common wheat JN177 and its close relative Thinopyrum ponticum via the asymmetric somatic hybridization. In comparison with JN177, SR3 has a stronger salt resistance ability, through the analysis of salt tolerance related QTL of the whole genome, we can make clear the genetic structure and mechanisms for salt tolerance of specific somatic hybrid introgression line Shanrong No.3, which makes a diffierence to study the effct to genomic and phenotypic variation of asymmetric somatic hybridization.In this study, a double haploid (DH) population was constructed between common wheat cultivar JN17 and wheat somatic hybrid introgression lines-- SR3. A high density genetic map was constructed by using SNP chip markers to analysis the QTL related to salt tolerance. The main results are as follows:1. The genotyping of both parents and DH population was applied using the wheat 90K SNP chip; a total of 14668 polymorphic SNPs were selected, consisting of 1781 single locus. The 1781 single locus constitute 36 linkage groups which spanned a total length of 5752.62 cM with an average distance of 3.18 cM between markers.2. QTLs of six traits for salinity tolerance using Qgene4.3 were analysised. A total of 47 QTLs were mapped on 14 chromosomes,1A、2A、3A、4A、5A、7A、 2B、4B、5B、6B、B.2D、4D and 5D. Among them,27 QTLs dispay genetic contribution over 10%. Among them,5 QTLs for seedling height were located on chromosomes 4B、4D、5B; 3 QTLs for root length were located on chromosomes 2A、 2B and 7A; 8 QTLs for fresh stem weight4A、5A、5B and 7A; 4 QTLs for dry stem weight were located on chromosomes IA、5A and 6B; 7 QTL for fresh root weight was located on chromosome 1A、1B、3A、3B、4A、4B and 5A; 1 QTL for dry root weight was located on chromosome 1A.3. QTLs of six traits for relative salinity tolerance using Qgene4.3 were analysised and 21 QTLs were detected. Among them,11 QTLs ’additive alles come from Ji’nan 17 and 10 QTLs’ additive alles come from Shanrong No.3. Among the LOD value is relatively large (greater than 5) ones, qDSW4B-2, qDSW5A-1, qDSW5B-1 from Shanrong No.3, genetic contribution rate werel7%,18% and 13%; qDSW4A-1, qDSW7B-1 Ji’nan 17, genetic contribution were 13% and 12%.