Gene Mapping Of A Fiberless Mutant Of Upland Cotton And Application Of High Resolution Melting

Cotton fiber is an important natural material for textile industry, cotton is an important economic crop and oil crop, and it also plays an important part in national economy. The epidermal cells of cotton ovule differentiate into lint and fuzz. Cotton fiber mutants are not only important genetic resources, but also model material of fiber development.Xuzhou 142 fiberless(XZ142w) is a fuzzless-lintless mutant of Upland cotton cultivars xuzhou 142(Gossypium hirsutum L.). This study constructed an F2 population of cross XZ142(♀) × XZ142w(♂) to investigate the inheritance of XZ142 w, and then mapping the mutant genes of XZ142 w with SSR and SNP markers, namely, naked genes li3 and n2. The optimized high resolution melting(HRM) technology was then used to screen the single nucleotide polymorphic(SNP) primer pairs designed from a comparative transcriptomic(-3 and 0 DPA) analysis between the two parents and genotype of SNP markers in F2 population, and the genotyping results was used for gene mapping. Main results as follows:1, 4000 SSR primer pairs were screened by polyacrylamide gel electrophoresis(PAGE) between XZ142 and XZ142 w, resulting 152 polymorphic SSR makers, and li3 and n2 were both anchored on chromosome 26(Chr26). According to the result of chromosome anchoring, 50 SNP primers were designed that were based on the differentially expressed genes with SNP in the transcriptiomes, 9 of them were polymorphic SNP primers between the parents through the HRM. SSR and SNP markers with polymorphism were used for F2 groups, and a linkage map of 106.5 cM(LOD=6) was finally constructed with JoinMap4.0. The li3 locus is flanked by two SSR markers, SWU17492 and SWU17386, which are 2.7 and 11.6 cM away, respectively; and n2 was mapped in a region of 19.1 cM flanked by the markers ICR20158(a SNP marker) and ICR36274(a SSR marker), 5.3 cM and 13.8 cM away, respectively.2, In this study, HRM technology was used for detecting the cotton SNPs, and the differences between the parents were successfully distinguished. HRM was used for genotyping of F2, and then the genotyping results and SSR data were used to construct linkage map. The detection process of LightCycler480 was optimized, namely, PCR amplification and dissolution curve were separated. The results show that optimized method is not only to keep high performance, but also the time of dissolution curve was shorten, which will significantly improve the detection efficiency.In this study, we constructed an F2 populations of gene mapping with molecular markers, and the genetic intervals of li3 and n2 of XZ142 w were found. HRM technology was used to detect SNPs and genotyping of F2 progeniture in cotton, and the results can be successfully used for gene mapping. This research lays a good foundation for further fine mapping and gene cloning.