Genome-wide Association Analysis Of The Anti-insect Factor Salicylic Acid In Tea Plant

Salicylic acid(salicylic acid,SA)is a ubiquitous endogenous signal molecule that can activate plant anaphylaxis(hypersensitive response,HR)and systemic acquired resistance(systemic acquired resistance,SAR).Salicylic acid can transfer and induce plant resistance in plants.To identify the genes related to salicylic acid in tea plants have a great significance for screening specific tea resources with high salicylic acid and cultivating tea varieties resistant to tea diseases and insect pests.In this study,299 local tea germplasm resources in Guizhou were used as materials,the core collection population of Guizhou local tea plant was sequenced by genotyping(GBS)sequencing technique,the salicylic acid content of the materials was determined by high performance liquid chromatography(HPLC),and the salicylic acid content and sequencing results of Guizhou local tea germplasm resources were analyzed by genome-wide association analysis(GWAS).The results are as follows:(1)phenotypic statistical analysis of salicylic acid content showed that enviroment 1,the skewness,kurtosis of salicylic acid content were-0.2590,-0.4360 respectively.In enviroment 2,the skewness was-0.3460,the kurtosis was-0.3390.(2)The analysis of population structure showed that 299 tea germplasm resources could be divided into 5 groups according to their growth status and species.Q1 have 16 materials,Q2 have 26 materials,most of them were modern local variety,Q3 have 13 materials,most of them were wild Camellia tachangensis(F.C.Zhang)population,Q4 have 106 materials,most of them were ancient local variety,and Q5 have 138 materials.(3)The nucleotide polymorphism(?),observed heterozygosity(HO)and Tajima'D analysis of 5 populations showed that 5 infer populations' s observed heterozygosity(HO)respectively are Q5=0.0842?Q4=0.0732?Q3=0.0462?Q2=0.0684?Q1=0.0596;5 infer populations' s Tajima'D respectively are Q5=0.6385?Q4=0.3479?Q3=0.5639?Q2=0.2130?Q1=0.2130;5 infer populations' s nucleotide polymorphism(?)respectively are Q5=0.2282,Q4=0.1925,Q3=0.1046?Q1=0.1742,Q2=0.1519?(4)FST between Q1 and Q3 is 0.2059,Q2 and Q4?Q5 is 0.1041?0.0640?0.0383;FST between Q2 and Q3 is 0.2714,Q1 and Q4?Q5 is0.1041?0.0584?0.0543;FST between Q3 and Q2 is 0.2714,Q4 and Q1?Q5 is 0.2287?0.2059?0.1099;FST between Q4 and Q3 is 0.2287,Q1?Q2?Q5 is 0.0640?0.0584?0.0361;FST between Q5 and Q3 is 0.1099,Q2?Q1?Q4 is 0.0543?0.0383?0.0361?(5)Combined with the results of GBS sequencing,79560 high quality SNP sites were selected.The genome-wide association analysis of salicylic acid phenotypic traits was carried out by using TASSEL software.Salicylic acid was associated with 6 models of(1)GLMQ=SNP+Q(2)GLMP=SNP+P,(3)MLMQ+K=SNP+Q+K,(4)MLMP+K=SNP+P+K,(5)CMLMQ+K,(6)CMLMP+K,22 SNP loci were associated with-lgp-value>5 as the screening threshold.Among them,there were 6 loci on chromosome 11,3 loci on chromosome 15,2 loci on chromosome 2,2 loci on chromosome 3,2loci on chromosome 3,2 loci on chromosome SCONTIG592.(6)In this study,according to the 22 loci associated,a total of 8 genes that may be related to salicylic acid were found,The serial numbers are respectively CSS0033791?CSS0037650?CSS0035116?CSS0017205?CSS0040476?CSS0032908?CSS0042839?CSS0011624.According to the functional annotation of each gene,the gene numbered CSS0033791,the gene numbered CSS0042839 may be related to the regulation of salicylic acid in tea plant.