Genome-wide Association Analysis Of Yield Related Traits In Upland Cotton(Gossypium Hirsutum)

As an important cash crop,cotton plays an important role in textile industry and edible oil utilization.Breaking the bottleneck of cotton yield have always been the goal of Chinese breeders.This study built 349 natural population of the upland cotton germplasm resources,through 10 × resequencing of the upland cotton genome-wide mutation detection technology,the data of 12 yield related traits in three environment are using on genome-wide association analysis to find yield relevant SNP loci.these results laid a foundation for further yield traits of the upland cotton.The main results are as follows:1.Variation analysis and correlation analysis of yield traits,The variation coefficients of BN,TRN,PSCY and CWR were all large in multiple environments,and the phenotypic data had wide variation.The correlation between yield traits and yield was complex.Most yield related data,such as PH,FBN,FSBS,BN,TRN and so on,were positively correlated with yield.The correlation coefficients of yield traits and yield in the three environments and BLUP values were ranked as BN > TRN > BW > FBN > PH > BW > SI > LP.2.Population struture and linkage disequilibrium analysis,A total of 25 Tb data and 1,980,000 high-quality SNP loci were generated by resequencing with an average depth of 11.65 ×.Through buliding Phylogenetic tree,PCA analysis and population structure analysis,349 upland cotton germplasm materials were divided into 3 groups.The analysis of linkage disequilibrium shows that the LD attenuation distance of the natural population is 300 Kb.3.Genome-wide association analysis: MLM(PCA+K)and MLM(Q+K)association models were compared,and MLM(Q+K)was determined to be the best association model for this natural population.A total of 153 significantly correlated SNP sites were identified for 12 yield traits,of which 47 were significantly correlated with plant height,31 were significantly correlated with boll number,and 39 were significantly correlated with boll weight.Moreover,compared with D genome,12 yield traits were associated with more SNPS in A genome.This study explored the basic principles and methods of the upland cotton GWAS analysis,provided references and suggestions for the application of the subsequent GWAS technology in the upland cotton,and laid a foundation for the upland cotton yield molecular breeding.