Response Of Seedling Biomass And Agronomic Traits In Maturity Stage Of Wheat To Nitrogen,Phosphorus And Potassium Deficiency And It's Genetic Analysis

Wheat is an important grain crop in China,and the low and medium yield fields account for about 2/3 of the cultivated land area,the deficiency of nitrogen,phosphorus and potassium is the main limiting factor of low and medium yield fields.The regulation of ratio of root and shoot is one of the important mechanisms for plants to adapt to nitrogen,phosphorus and potassium nutrient deficiency environment.This study used " Tainong 18× Linmai 6" derived RIL population as the research sample,set up CK,LN,LP,LK,a total of four treatments.The responses of biomass and root-shoot ratio at seedling stage and agronomic traits at maturity stage to N,P,K deficiency were studied by combining seedling liquid culture with field test,and quantitative traits locus(QTL)was analysed.The main results were as follows:1.Under the LN,LP and LK treatments,the RSDW trait increased significantly and TDW decreased significantly.LN treatment reduced SN,GNS and GLW of wheat,LP treatment decreased PH,SN and BSSS significantly,LK treatment reduced the PH,SN,TGW and BSSS of agronomic traits significantly.2.The biomass and root-shoot ratio traits at seedling stage,main agronomic traits at maturity stage and related responsiveness traits were significantly affected by both genetic and environment factors,and the heritability of tested traits was higher under different N,P,K treatments.18 selected traits of variation between different genotypes reached extremely significant level.The generalized heritability of seedling traits was 66.66% to 77.24%,and that of agronomic traits at maturity ranged from 51.50% to 93.68%.3.Under treatment of CK,LN,LP and LK,there was a stable and significant correlation between phenotype data of different traits.RSDW had extremely significant positive correlation with GNS and SL,and had extremely significant negative correlation with SN and BSSS.PH had extremely significant positive correlation with SN,TGW and GL.SN had extremely significant positive correlation with BSSS,and had extremely significant negative correlation with GNS,TGW and GW.GNS had positive correlation with TGW and GW,and had extremely significant negative correlation with BSSS.4.TDW and RSDW of seedling stage in a total of 40 to locate QTL,distribution on chromosome 10(1D,3B,3D,4A,4B,5A,5D,6A,6B and 7D),a single QTL explain genetic contribution rate was 5.01% ~ 54.41%,the biggest LOD value was 38.66.Among them,21 QTL additive effect from TN18 and 19 QTLs were from LM6.A total of 3 RHF-QTLs weredetected on 4B and 6B chromosomes.QRsdw-4B could be detected in 7 treatments,the average contribution rate was 21.31%,which played an important role in the adaptation of wheat to different N,P,K environments.5.A total of 431 QTLs were located for the 11 agronomic traits(PH,SL,SN,GNS,TSS,BSSS,TSSS,TGW,GL,GW,GLW)at maturity stage,included 73 RHF-QTLs which were distributed on 20 chromosomes except 3D.The genetic contribution rate of a single QTL was0.05% to 65.60%,and the maximum LOD value was 194.77.The additive effects of 230 QTLs were from TN18,201 QTLs were from LM6.6.A total of 30 QTLs were identified of 18 N,P,K deficiency responsivity indexes of 6traits(RTDW,RRSDW,RPH,RSN,RGNS,RTGW)on 12 chromosomes The explained genetic contribution rate of a single QTL was 4.57% to 19.49%,and the maximum LOD value was 45.12.1 RHF-QTLs were detected on 4B chromosomes.The additive effect of 19 QTLs was derived from TN18,11 QTLs from LM6.7.The total 35 RHF-QTLs form 14 QTL clusters(C1-C14),and at least 2 RHF-QTLs were located in these QTL clusters at the same time.containing 13 traits,distributed on 11 chromosomes.The co-located QTL of these multiple traits indicate that different traits may be controlled by a common QTL/gene,and also indicate the potential genetic relationship between them.8.There may be a close genetic relationship between RDW and RSDW at seedling stage and important agronomic traits at maturity stage.QTL clusters C7 simultaneously locates 7important RHF-QTLs of RDW and RSDW at seedling stage and agronomic traits at maturity stage,average contribution rate reached 26.6%,indicating that this QTL is an important QTL related to the genetic control of RDW and RSDW and agronomic traits in both seedling stage and maturity stage,and has the value of in-depth study.