Seedling Cold Tolerance Evaluation And Genome-wide Association Analysis Of Rice Core Collection Group

150 parts of rice core collection group as materials were identified and evaluated the seedling cold resistance and based on a simplified genome sequencing technology （SLAF-seq） to build SLAF-seq library and develop genome-wide SNP marker, which were combined with cold tolerance phenotype data to conduct genome-wide association analysis. The results showed that the variation of seedling cold resistance of core collection group was rich and showed a trend of obvious normal distribution. Screened and identified 5 parts of extremely strongcold resistance material,9 parts of extremely weak cold resistance material. Got 24889 polymorphism SNPS markers with high quality and detected 26 SNP loci which were associated with seedling cold resistance significantly by mixed linear model procedure of TASSEL software. The markers on the chromosome 6,8,10 were at most, all of them were 4 markers. The marker whose contribution rate was the greatest located on chromosome 6 and explained 33% of phenotypic variation.we retrieve 43 genes have been cloned near significant site, has been positioned 42 QTL and 93 nominated candidate genes. Scanning the genes near 26 significant correlation SNP loci, we detect 43 cloned genes and 42 positioned QTL in±200Kb,while in the±20Kb range we detected 93 candidate genes. The cloned gene DREB1C and the identified gene qCTB8 have been confirmed to be related to the cold tolerance of rice.DREB1C is located on the sixth chromosome, which is 113471bp away from the significantly related to SNP₁320300; qCTB8 is located on the eighth chromosome, which is 130441bp away from the significantly related to SNP₂824184.The gene expression analysis showed that the expression levels was significantly changed between these two genes in the extreme materials. We have further analyzed the candidate genes that have been detected, The results showed that the expression levels of some genes were significantly changed after cold treatment, such as the gene Os01g0791150, which located on the first chromosome that is 18884bp away from the significantly related to SNP₃5276904.The preliminary judgment found that these genes were associated with cold tolerance, however the cold tolerance mechanism was not clear, we need the further study. The results of this study provided the gene source for cold tolerance research and molecular breeding of rice, it also provided a basis for the cloning of cold tolerance candidate genes...