Genetic Analysis And Linkage Marker Development Of Black Glume Traits In Wheat

Wheat is one of the main grain crops in China.An all-round study on wheat is helpful to promote its stable and prolific growth trend.Glume color is one of the key factors of wheat morphological identification.The study of glume color is of great significance to research on breeding,evolution and gene cloning.In this study,the genetic analysis of the black glume character of wheat strain 15N44 was carried out through the combination of chip scanning technology and SSR marker.The results were as follows:1.The black glume wheat strain 15N44 and white glume wheat strain CH1521 were used as parents to cross to obtain the F₁ population,the F₁ population was backcrossed with the parents to obtain the BC₁F₁ population respectively,and the harvested F₁ seeds were sown and hybridized to obtain the F₂ population,and the seeds harvested from the F₂ single plant were planted in the field to obtain the F_2:3 families.DNA was extracted from leaves at the seedling stage,and glume color traits of F₁,BC₁F₁,F₂ and F_2:3populations were identified and recorded at maturity stage.A total of 129 single plants were harvested from the F₁ population,all of which exhibited black glumes;A total of105 single plants were harvested from the BC₁F₁（15N44/CH1521//15N44）population,all of which exhibited black glumes;158 single plants were harvested from the BC₁F₁（15N44/CH1521//CH1521）population,of which 82 exhibited black glumes and 76exhibited white glumes.The ratio was 1.08:1,which was determined by chi-square test to be consistent with the segregation ratio of 1:1;227 single plants were harvested from the F₂ population,of which 168 showed black glumes and 59 showed white glumes,with a ratio of 2.78:1,which was determined by chi-square test to be consistent with the segregation ratio of 3:1.After analyzing the phenotypic identification results,it was concluded that the black glume trait in wheat strain 15N44 was controlled by a single dominant gene,which was inherited by nuclear inheritance and named Bg1.2.Based on the phenotypic identification results of F_2:3 lines,30 pure black glume monocots and 30 pure white glume monocots were selected from their F₂ generation,and their DNA was taken in equal amounts and mixed separately.,extreme gene mixing pools of black and white glume were constructed,and the 90K SNP chip was used for the whole genome detection of the mixing pools.113 SNP differential sites were obtained after removing the signal deletion sites and SNP marker sites that are heterozygous in the chip scan,among which 58 were distributed on chromosome 1A.There were 11 SNP differential loci on chromosomes 1B and 1D accounted for 9.3%of the total.There were24 SNP differential loci on chromosome 2 accounted for 21.2%of the total number,and the remaining 20 SNP differential loci were scattered on other chromosomes.It was concluded that wheat black glume gene Bg1 was located on chromosome 1AS.3.A total of 120 pairs of SSR markers were designed based on the results of chip scanning and the gene sequences on 0-14 Mb of Chinese Spring.59 pairs of markers with polymorphism in parents 15N44 and CH1521 were first screened by PCR amplification and polypropylene gel electrophoresis.The 11 pairs of markers linked to the target genes were then screened by a small population consisting of 11 pure black glume monocots and 11 pure white glume monocots from the F₂ population.which were 1AS05,1AS08,1AS17,1AS48,1AS61,1AS76,1AS80,1AS89,1AS111,1AS114 and 1AS119.After amplification of the linked markers with all the single plants in F₂ population,the bands on the gel map of polypropylene electrophoresis were analyzed.Finally,the black glume gene Bg1 was located in the genetic interval of 2.5 c M between the linked markers1AS17 and 1AS48.The genetic distance between Bg1 gene locus and 1AS17 was 0.3 c M and that between Bg1 gene locus and 1AS48 was 2.2 c M.This study provides a preliminary localization of the black glume gene of wheat strain 15N44,which will lay the foundation for its fine localization,and then contribute to the cloning study of the black glume gene of wheat.