| In this study,we developed two recombinant inbred lines(RIL)for quantitative trait locus(QTL)mapping of soybean yield related agronomic traits.We adopt a resequencing strategy for parents and reduced-representation genome sequencing strategy for the individuals in the two populations for developing molecular makers.QTLs identified in this study were consistent with other reported studies.According to the resequencing data of the parents,we found polymorphism loci within confidence interval of the QTLs for the next study of fine mapping.And we also obtained the knockout mutant plants of the soybean circadian clock gene Gm ELF4 b,and its effect on soybean flowering time and leaf senescence was preliminarily analyzed.The two RIL populations in this study were E1 and e1-as background,respectively.From the QTL analysis results we found that the QTL interval of soybean growth period related traits were overlapped with those of other yield related QTLs.This might prove that the growth period traits may be one of the important factors that affect production.It might be pleictropism effect that the same site controls different traits.And it was also possible that different QTLs of different traits were mapped in the same interval.SE population was E1 background,two QTL analysis methods were chosen to detect QTLs of different traits in different environment.Three QTLs of growth period related traits could be stably detected.They were on chromosome 6,11 and 16,respectively.The QTL on chromosome 6 was the major QTL influencing R1、R8 and RP traits,tightly linked with E1,it might be the known E7 site.In addition,QTLs,whichcontrol branches number,pod number and grain number traits,were also located in the same interval of growth period related traits QTL on chromosome 6.The QTL on chromosome 11 mainly detected in post-flowering and maturity traits,speculated that it might be mainly affect the post-flowering growth and development process of soybean.The QTL on chromosome 16 was detected in the pre-flowering period and maturity traits,speculated that it might mainly play role in the early flowering regulation processes.The hundred grain weight QTL was on chromosome 19,which contained the Dt1 locus.And there was polymorphism between SE parents in Dt1,it proved that Dt1 may regulate soybean seed development,affect the hundred grain weight.DW population was e1-as background,one major QTL on chromosome 4 could be stably detected in different environments and the reported E8 locus was within the QTL interval,we speculated that we locate the E8 site.Hundred grain weight QTL was also detected in this interval.Branch number QTL was also detected on chromosome 6 in DW population.According to the physical position of the molecular markers within the confidence interval,QTLs in the two population were overlapped.And DW population was not detected growth period related QTLs in this interval,we speculated that candidate genes of controlling branch in this two population might be different.It might also be the same,but had no relationship with controlling growth period traits.The mutant plants of Gmelf4 b flowered five days earlier than the control group in the long day conditions in artificial climate chamber.Gm FT2 a and GmFT5 a were up-regulated in the mutant materials.We analysised the expression level of GmELF4 a and GmELF4 b in E1,E2,E3 and E4 near isogenic lines of Harosoy background.E1 repressed the expression of Gm ELF4 a and Gm ELF4 b,E3 and E4 accelerate the expression of GmELF4 a and GmELF4 b.E2 had no significant influence.The leaf of Gmelf4 b mutant showed early senescence phenotype.And transcriptome sequencing found that the expression of gene PR1,which is related to plant aging and disease-resistance,was significantly up-regulated in MAPK signal transduction pathway.Through the screening results of yeast c DNA library,we found that GmELF4 a and GmELF4 b protein may interact with some transcription factors to regulate the growth and development of soybean. |
