Genome-wide Association Mapping Of Salt Tolerance Trait In The Germination Period In Brassica Napus

Rapeseed is an important oil crop,and provide the residents’ consumption 60% of plant oils.germination stage of rapeseed is a sensitive period to salt stress,and the salt stress has adversity influence on rapeseed germination and growth.In the present study, the natural population included 214 rapeseed with extensive genetic diversity was used to investigate the germination potential, germination rate, root length, stem length and fresh weight,Genome-wide association analysis performed with 19,167 SNPs was conducted for these five traits.The analysis of population structure and relative kinship : The natural population is divided into two groups, PI and P2, group P1 contained 26 lines accounted for 12.15% of all the lines. The 26 lines were mainly from western of China. The rest 188 rape belonged to group P2 accounted for 87.85% of all the lines. They were mainly from southern of China. In addition, the kinship between any two lines below 0.05 accounted for 68%, and about 55%pairs of lines is near to 0. Which showed that Show that there is no obvious relationship between material.The Genome-wide association study of B.napus seed germination under salt stress:The contrasting among the model K、Q and K + Q, showed that model K + Q is the optimal model for this experiment. under the best model K+Q, 6 loci are detected significantly associated with B.napus rape seed germination under salt tolerance, Among these loci, three loci have significantly associated with relative germination rate,one loci is significantly associated with relative stem length and the rest two loci are significantly associated with relative fresh weight, but there is no loci to be found that significantly associated with relative germination potential and relative root length, in order to find the loci that likely to be associated with this two salt stress indexes as much as possible, choosing K model and Q model as the statistical model to test, finally 24 loci were detected, fifteen loci are significantly associated with relative germination potential, eight loci are significantly associated with relative root length,These loci are all located on the chromosomes except A2、A4 and A7,and could explained the phenotype variation from 0.061（Bn-scaff₂2183₁-p675530） to0.1196（ Bn-A06-p2307291）,and are all reliable and stable.