QTL Mapping For Main Agronomic Traits In Wheat Under Various Nitrogen Supplying Dates

QTL mapping for main anionomic traits were studied using a168-line doubledhaploid(DH) population derived from two elite Chinese wheat cultivars Huapei3and Yumai57. QTL analyses were performed using the software of QTLNetwork2.0. QTL for10traitsunder various nitrogen supplying dates, the results were as the following:1. Doubled haploid(DH) population were construed with parent line Huapei3and Yumai57. Four nitrogen supplying dates were set.We inquired plant height,ear length,ear lowersegment length,flag leaf length,flag leaf width,Sterile spikelets per spike,fertile spikelets perspike,grains per spike,thousand kernel weight and grain protein content. The results suggestedall the traits were coincided with the normal distribution function. So they were suited to beanalyzed with QTL.2. Analyzing plant height related traits of wheat under various nitrogen supplying dates.55QTL were detected under four nitrogen supplying dates.13QTL from controltreatment(T0),14QTL from nitrogen application at regreen stage(T1),14QTL from fertilizertopdressing at jointing stage(T2) and14QTL from nitrogen application at flag leaf stage(T3).The phenotypic variance explained by single QTL varied from0.16%to17.49%.Such asQPh3A, QPh4D-1, QPh4B, QSl6B, QSl7B-1, QIlbs4B-1, QIlbs4D and QIlbs7D were detectedunder multiple nitrogen supplying dates.3. Analyzing flag leaf related traits of wheat under various nitrogen supplying dates.29QTL were detected under four nitrogen supplying dates.Including7QTL from controltreatment,9QTL from nitrogen application at regreen stage,7QTL from fertilizer topdressingat jointing stage and6QTL from nitrogen application at flag leaf stage.QFll2D, QFll5B andQFlw1B-1were only detected in T0.4. Analyzing spike related traits of wheat under various nitrogen supplying dates.28QTLwere detected under four nitrogen supplying dates.Including5QTL from control treatment, 11QTL from nitrogen application at regreen stage,7QTL from fertilizer topdressing atjointing stage and5QTL from nitrogen application at flag leaf stage.Hereinto, QSsps2D andQSgn2B were detected under four nitrogen supplying dates.5. Analyzing grain traits of wheat.23QTL were detected under four nitrogen supplyingdates.6,6,5,6QTL were detected,respectively.The phenotypic variance explained by singleQTL varied from2.88%to10.04%.Qtgw5B, QGpc6A, Qtgw3A, QGpc2A-2were onlydetected for the measured trait under a certain nitrogen supplying, Qtgw2D-2was detectedunder all nitrogen supplying dates.