| Cottonas an important cash crop, provided the most important nature textile fiber, and plays an important role in many different countries. Two types of cotton fiber, including lint and fuzz are developed from single epidermal cells of the seed. The long fiber can be rolled down from the seed surface but the short fiber cannot. The fuzzless mutants are not only important materials to study the fiber initiation and development, but also important resource for cotton breeding.In this study, we used the F2 population, obtained from the hybridization of fuzzless mutants and wild fuzz parents of G. hirsutun and G. barbadense. Using the traits of fuzz and chromosomal localization, we found that the n2 gene was localized on the A12 chromosome. Also, we sequenced the 1DPA,3DPA ovules and the mixture ovules and fiber of 5DPA transcriptome of four lines from the RIL using the next-generation sequencing technology. (Illumina HiSeq 2000 Platform).1. Genetic analysis of the fuzzless phenotype in cottonThe F2 population from the hybridization of fuzzless mutants (FLMs) and wild fuzz parents were used to investigate the phenotypes and chromosome mapping. The results showed that the fuzz trait was controlled by a pair of genes.2. Molecular mapping of the fuzzless gene n2We used the interspecfic population (n2NSM XH25) F2 consisted of 95 individuals to map the n2 gene. According to the results reported previously of our lab, the SSR markers were anchored on the Chr.A12, Chr.D12. We used the SSR markers designed according to the genome sequence of Graimondii to linkage analysis in the F2 population with 95 individuals. The results showed that the fuzzless locus was mapped nearby to the marker of H2, H3, H4, H5 and H6, and further,n2 was located between H4 and H5, with a distance of 2.77 cM anchoring D sequence of physical distance is 82Kbp.3. Transcriptome sequencing and differential expression analysisTwo diploid cotton species(jianglingzhongmian zhejiangxiaoshanlvshu) RIL, i.e. Gossypium arboreum. Four materials of 474,477,480 and 483 in RIL. After data pre-processing,Due to the completion of the cotton diploid A genome was sequenced, the data has not been announced, Thus, we chose to further analyze the data by applying de novo strategy.In order to conduct a comprehensive analysis of the genome, and at the same time, double objective difference comparison, we use the method of de novo mosaic,the cDNA libraries were also assembled together as a reference transcriptome using Trinity. The data sets corresponding to G. Arboreum, G arboreum were assembled into 154581 transcripts, respectively, clustering into 79977 individual clusters. The N50s of the unigenes are remarkably high, achieving 2233 respectively.the results of different genes:First group to gene rarely, only related to lipid metabolism genes;Second sets of genes enriched in photosynthesis, hormone metabolism, abiotic stress, protein synthesis related genes; Third sets of genes enriched in RNA metabolism, protein synthesis, signal receptor, calmodulin genes; Fourth gene set enrichment to the cell wall synthesis and other cell wall proteins, lipid metabolism, secondary metabolism, hormone metabolism, nucleic acid metabolism, chromosome formation, signaling receptors, cytoskeleton, development of storage protein related gene; Gene enrichment to the fifth groups are some reverse regulation gene.According to the third chapter of fuzzless localization results recessive gene n2, combined with the correlation analysis of transcriptome sequencing, found three differentially expressed genes in the vicinity of the positioning block, wherein Genel is related to the gene is the main impetus of super family protein subunit 2; Gene2 is NAC family genes; Gene3 is ribonuclease 3. |
PDF Full Text Request