Genetic Research Of Heading-time Related Genes In Wheat Line XN6426 And Development Of Near Isogenic Lines Of Gene ZCCT-1 In Bread Wheat

Wheat is one of the most important food crops.Heading time is closely related to its adaptability,yield and quality.It is important for breeding and producing of the wheat to analys heading-time related genes and develop their near-isogenic lines.In this study,we dated the heading time of the wheat line XN6426 planted in controlled greenhouse with high-temperature(16~25?)and long-day lighting(?16 h)to identify the character of springness and winterness,analysed the composition of heading related genes in the line XN6426 with developed and newly designed molecular markers.The heading related genes of line XN6426 were mapped by the SSR markers based on deduction from different SNP loci between early and late heading pools.Different allele types of ZCCT-1 gene in different wheat populations were dected,and transferred the target genes to near-isogenic lines by backcross methods.The main results were as follows:1.Combinations of heading related genes which are mainly known in line XN6426: The growth habit of wheat line XN6426 was spring by heading-time under controlled greenhouse with high-temperature and long-day.Its heading related genes were detected by using known molecular markers.Photoperiod gene loci in line XN6426 were composed by light-insensitive alleles.The alleles at Vrn-A1,Vrn-B1,Vrn-D1,Vrn-B3,Vrn-D4 loci in line XN6426 are recessive,indicating that those genes were composed by the recessive alleles.Genes ZCCT-A1 and ZCCT-B1 missed in line XN6426.We cloned part of ZCCT-1 gene with newly designed markers.Sequence alignment with the known AS75 sequences,the 33 Arg in the CCT domain of ZCCT-D1 gene in XN6426 mutated to glutamine Q.Also,we cloned the ZCCT-D2 gene,did not find any difference in the CCT domain of XN6426.But there were three amino acid deletions which also founded in Chinese spring,and the ZCCT-D2 gene in XN6426 had three specific mutation points of amino acid.2.Mapping of heading related genes in wheat lines XN6426: The heading time of F2population(XN6426 × Jing 411)was dated in controlled greenhouse with high-temperature and long-day.Continuous distribution and obvious peaks in F2 was found.The heading time in F2 was controlled by two genes using SEA-F2 software.This result was also confirmed inthe F2 population planted in the field.We built early and late heading pools.SNP polymorphism between the two pools were analysed by wheat 90 k SNP.The results showed that the frequency of polymorphism SNPs in the chromosome 4B,5B and 5A were relatively higher.The SNP dense were different in the different area of the chromosomes.There was one region in the chromosome 1A,1B and 6B,respectively,two regions were founded in 5A and5 B chromosome respectively.And many SSR markers were found in dense regions and districted that was near the dense regions.The bands from markers Barc151 and Wmc327 have polymorphism between the parents' and the polar pools.Furthermore,we screen the F2 population with the markers Barc151 and Wmc327 that we chose and found one QTL near Barc151 and Wmc327.3.Transferrig the near isogenic lines of wheat ZCCT-1 gene: We got 15 variation alleles which contained different ZCCT-1 genes by screening the F2 population carrying on different mutation types.We selected jin411 and jingdong8 as recurrent parent to produce BC1 and BC2 by the use of backcross method.