Analysis of grain quality traits and their QTL using F_2:5 pedigrees derived from Ningchun No.4×Hedong black wheat

【Objective】 Quality traits and their important QTLs of F_2:5pedigrees derived from the cross between Ningchun No.4 and Hedong black wheat were analyzed.It would provide good resources for quality traits improvement of wheat in Ningxia.【Method】 Ningchun No.4,Hedong black wheat and 248 F_2:5pedigrees derived from the cross between above two parents were as materials.By means of variance analysis,correlation analysis,cluster analysis and composite interval mapping method,twelve grain quality traits and their important QTLs were studied.【Result】 The distribution of twelve quality traits in F_2:5pedigrees were obviously separated,the average values of moisture content,water absorption rate,sedimentation value,stabilization time and hardness index were all over the high parents,the proportions of ultra-high parents were 59.27%-92.74%.The average values of crude protein content,wet gluten content,flour yield rate and formation time were between those of high parent and low parent,the proportions of over mid-parent were 42.34%-50.81%,and the proportions of over high-parent were 12.50%-27.42%.The average values of falling number,extension area and volume weight were all below the low parents,the proportions of over mid-parent were 1.61%-33.87%,and the proportions of over high parent were 1.61%-31.05%.Based on the measured results of grain quality traits,248 pedigrees were divided into six clusters at Euclidean distance being 13.GroupⅡhad the highest average wet gluten content(32.16%)and falling number(363.55 s).GroupⅢwas the first place in crude protein content(14.89%),water absorption rate(62.88%),extension area(152.28 cm²),volume weight(779.20 g/L),formation time(4.15 min)and hardness index(69.93).GroupⅤhad the lowest moisture content(11.68%)and the longest stabilization time(13.16 min).GroupⅥhad the highest flour yield rate(68.86%)and sedimentation value(41.31 m L).Sixty-eight quality trait QTLs were detected in thirty-nine intervals constituted by sixty-nine SSR molecular markers.Among them,QTLs of moisture content,crude protein content,wet gluten content,flour yield rate,water absorption rate,falling number,sedimentation value,extension area,volume weight,stabilization time,formation time and hardness index were 5,2,4,9,2,12,4,4,1,9,9 and 7,respectively.They were distributed in 16 chromosomes including 1A-7A,1B,2B,3B,6B,1D,2D,3D,6D and 7D.Their maximum LOD score was 3.03,the contribution rates to phenotype were 3.17%-43.81%,and additive effects were-14.8275-15.3442.Multiple QTLs of grain quality traits were detected in chromosomes 1A,2A,4A,7A,2B,3B,6B,1D,2D,3D,6D and 7D.The results showed that QTL enrichment regions of quality traits existed in the 12 chromosomes.【Conclusion】 Most of the quality traits belong to quantitative traits controlled by multiple genes in wheat.There are many over parent types in F_2:5pedigrees derived from the cross between Ningchun No.4 and Hedong black wheat.GroupⅢbelongs to the best excellent group of grain quality traits.Sixty-eight detected QTLs may be used for the genetic improvement of grain quality traits in wheat.