Genetic Variation Of Yield And Quality Traits In Radiation Mutagenesis Population Derived From Cotton J02-508

Cotton is one of the most important cash crop in our country,natural cotton fiber is the raw material of the textile industry.The improvement of fiber quality and yield plays significant roles in cotton industry,the cultivation of new cotton varieties with the actual production target is helpful to improve the economic benefits of cotton industry.To explore the genetic structure of cotton yield,fiber quality and other traits,this study used ⁶⁰Co-?-ray radiation to treat J02-508,a variety of Upland cotton?Gossypium hirsutum L?,and obtain 224 mutant lines.A genome-wide association analysis was carried out based on the phenotypes and whole genome sequencing molecular markers in the M₄ mutant population using the MLM mixed linear model.The main results are as follows:1?The treats in M₄ generation population of J02-508 mutagenesis tended to be stable.The variation range of trait BW?20.82%-37.36%?and PH??7.11%-9.41%?is the largest,the variation of trait MAT??0.67%-0.55%?and FU??0.62%-1.06%?is the smallest,and other traits also have varying variation,such as BS??14.55%-?8.71%?,LP?1.02%-14.09%?,FL??4.70%-?0.59%?,FS??11.54%-?6.61%?,FE??2.31%-4.31%?,FMI??5.58%-4.93%?,SFI??1.69%-14.90%?,SCI??11.11%-?3.06%?.A series of mutant lines have been selected,six high rod mutant lines,such as Gh1916,Gh1942;two dwarf mutant lines,Gh1960,Gh2063;four mutant lines with good fiber quality,such as Gh1918,Gh2011;five mutant lines with poor fiber quality,such as Gh1920,Gh1923.Provided mutant materials for the selection of individual plant with targete traits.2?Based on whole-genome resequencing,5,348,977 high-quality SNPs loci were obtained for subsequent genome-wide association analysis,including by filtering markers with a reading rate of less than 80 percent or minor allele frequency less than 2 percent.These 5,348,977 high-quality SNPs data were covered within the entire genome 26 chromosome with 2218,377 Mb interval,and an average distance of 0.415 Mb between the markers,and 2,642,155,2,706,822SNPs were distributed on the A subgroup and D subgroup,respectively,it indicates that population variability is abundant.3?Based on the SNP genotype analysis of principal component,Neighbor-Joining?NJ?phylogenetic tree and kinship,221 mutant lines in J02-508 mutagenesis M₄ population were divided into five subgroups,and the trait difference between subpopulations were obvious.4?A series of trait-related candidate genes was detected by a genome-wide association analysis of 12 traits with 5,456,587 SNPs within the mutagenesis population using the MLM mixed linear model.A total of 141 candidate genes were detected,14 candidate genes were related to the fiber length and lint percentage;12 candidate genes were related to the fiber length;candidate genes Gh_A01G053700.1 and Gh_A10G235200.1 were related to the lint percentage;60 candidate genes were related to the fiber micronaire;and 53 candidate genes were related to the other traits,like boll weight and fiber maturity index.