Genome-wide Association Studies (GWAS) Of Several Economic Traits On Nibea Albiflora (Richardson)

In order to seek the molecular markers and candidate genes affecting the economic related traits of Nibea albiflora “Jinlin NO.1”,there were four economic taits,the growth,net weight rate,swim bladder index and gonadosomatic index studied by GWAS.It provided basic data for the study of the genetic improvement and control mechanism of the Nibea albiflora.The results of this study were as follows:1、In the study,there were four morphological traits,the body length,body height,body thickness,and body weight of the 16-month-old “Jinlin NO.1”（393 fish）that were significantly positively correlated.Among them,the correlation coefficient and determination coefficient of body length to body weight were the largest,indicating that the three morphological traits were the main traits that affected body weight.There was a significant correlation between the net weight rate,the swim bladder index and the gonadosomatic index（P < 0.01）,but there was a significant negative correlation between the gonadosomatic index and the swim bladder index.2、In this study,we performed a genome-wide association analysis of four traits in 39316-month-old “Jinlin NO.1”（393 fish）.Amount of sequence per individual was 1.372 Gb.A total of 498,932 SNP markers were cleaned and 81,991 effective SNP markers were obtained after filtration.None of the four traits were achieved genome-wide significantly related SNP loci by using the EMMAX model,but there were some clusters of SNP with significant correlations.There were 12 clusters of SNP related to growth traits that were screened.These SNP clustered mainly in LG1,LG6,LG8,LG9,LG17,LG21 and Unassembled_scaffold.According to the results,some SNP were related to more than one trait,such as YD14388.t1,YD14360.t1,YD13280.t1,YD13283.t1.They had a large association with weight traits,so did body length.It is suggested that these traits may be controlled by the same gene（with pleiotropic effect）or closely linked genes.Based on six different SNP clusters,13 potential candidate genes associated with growth traits were screened out,including camsap1,col27a1,tbx18,ept1,zfhx2,loc104918090,at1g35710,zfhx2,lcorl,ppp2r2 c,arhgap29,olfm3,loc104931259.Their functions were mainly involved in the regulation of biological processes,cell morphology,and the structure of skeletons,embryonic development and bone tissue development.3、we performed genome-wide association analysis on the three traits of 16-months-old“Jinlin NO.1”,net weight rate,swim bladder index and gonadosomatic index,and selected 3,4and 3 related SNP clusters respectively.These clusters of SNP mainly distributed in LG2,LG9,LG12,LG20 and LG21.Two SNP locus in LG2₁4124885 was found to be significantly associated with the swim bladder index（P < 0.01）.Six SNP with significant association trends and seven related functional genes were also screened out,including bmp1,stom,stbd1,shroom2,loc104923519,gli2 and inhbb.A total of 18 functional genes were screened out for the three traits.In this study,most of these genes are transcriptional regulators and are involved in the regulation of cell cycle,which may affect the net weight rate,swim bladder index,and gonadosomatic index.Some genes screened out were reported in fish.