Identification Of Quantitative Trait Loci For Grain Weight Related Traits In Wheat Founder Parent ‘Linfen 5064’

Founder parents play a vital role in wheat breeding and production.However,the founder parents are summarized based on the subsequent pedigree analysis.How they were derived from a large panel of germplasm,and the essence of being able to breed a large number are the core issues.As a founder parent,Linfen 5064 has the characteristics of short plant height,large kernels,high quality,early maturity,and disease resistance.In this research,a total of two DH populations LN and LJ were constructed by crossing between Linfen 5064 × Nongda 3338(LN)and Linfen 5064 ×Jinmai 47(LJ),respectively,in which "Linfen 5064" was used as the female parent,and Nongda 3338(LN population)was male parent.Here,the traits associated with grain yield(grain size and grain filling stage)in nine environments were studied via QTL mapping,and then identified genomic regions associated with the important traits in founder parent Linfen 5064.Furthermore,its molecular genetic mechanism was analyzed subsequently.The subsequent analysis are as follows:1.A total of 72 stable QTLs associated with the grain yield were identified located on chromosome 4B,5A and 6A of two DH populations,with the phenotypic variance explaining(PVE)ranging from 1.93%-37.17% and 1.80%-48.78%,respectively.Totally 15 QTLs were found to be special from founder parent Linfen5064 with PVE more than 10%,in which QTL-2D,QTL-6A.1 and QTL-7A were identified in two populations.Through Meta-QTL analysis,a total of 64 MQTLs associated with thousand-grain weight(TGW)were detected,and the minimum confidence interval(CI)was 1.09 cM,which presented 5 core MQTLs overlaps with Linfen 5064.In conclusion,the detected QTLs regions from founder parent Linfen5064 seems to be crucial for TGW-related traits.2.A total of 15 QTLs genomic regions were detected from Linfen 5064 via the analysis of additive effects.The genetic effects were higher in Linfen 5064 than that in Nongda 3338 and Jinmai 47.Finally,the excellent allelic variations with Linfen5064 could result into the increased TGW by 2.26g-6.51 g,grain length by 0.04-0.21 mm,grain width by 0.06-0.13 mm,grain thickness by 0.05-0.09 mm,and grain filling by 0.07-0.31 mm.Among them,the TGW and grain thickness in the QTL-6A.2genomic region had the largest yield-increasing effect(6.51 g,0.08mm).