| Maize banded leaf and sheath blight (BLSB), caused by Rhizoctonia solani Kiihn, was a destructive disease that results in significant yield loss in most maize-growing areas in Southwest of China. Maize disease resistance molecular breeding based on discovering of resistance related BLSB genes and development of resistance maker, was an effective approach to enhance maize resistance and reduce yield loss. And on basis of phenotype evaluation, whole genomics which was used to gene association analysis had been an effective method for disease resistance gene isolation and identification. A maize association mapping population consisted of 144 maize inbred lines was constructed as our research materials. The disease resistance phenotype was evaluated under the condition of artificial inoculating, the population genetic diversity and structure was analyzed combined with SNP maker of whole genomics and the SNPs correlated with BLSB resistance were located by association analysis which was on base of whole genome screening. The main results were as follows:1. The 144 maize inbred lines were identified by artificial inoculated Rhizoctonia solani in Yaan Sichuan province and Xishuangbanna Yunnan province. The results of showed that in 2010 there were 77 high sense,61 middle sense and 6 middle resistance; in 2011 there were 1 high resistance,24 middle resistance,45 high sense and 74 middle sense. 5 of the 144 showed high resistance (HR) or middle resistance (MR), which accouted for 3%of the all materials. The average disease index of R01C060 in the two seasons was 10.41 and 7.41 and it was the only one who showed high resistance in the 144.2.45,295 SNP makers were obtained in this research which was of high quality and diversity. The average gene diversity was 0.365 and the variation range was 0.095-0.500; The average PIC was 0.291 and the variation range was 0.090-0.375 distributed in 0.350-0.375. There wer 6459 SNPs distributed on chromosome 1, accouted for 14.46% and the other 7.12%-11.40%distributed on other chromosomes.3. The genetic diversity of association mapping population was analysed by 45925 SNPs which covered the whole genomics of maize. Population structure analysis showed that the 144 inbreds could be classified into 3 groups and 6 subgroups which corresponding to the six main germplasm sources:PA, PB, Lan, SPT, LRC and BSSS.4. The association analysis results based on whole genome screening showed that under the consideration of population structure and P<0.001, the number of SNPs associated with lesion height, relative lesion heigth, disease rate and disease index were 54, 39,45 and 305 in 2010; the number of SNPs associated with lesion height, relative lesion heigth, disease rate and disease index were 72,53,102 and 246 in 2011. And the SNP makers, which associated with lesion height, relative lesion heigth and disease index, both detected in 2010 and 2011 were 9,2 and 53.5.94 SNPs loci were explored after blast in NCBI, MaizeGDB and other data base while 17 SNPs of which were mapped in the BLSB resistance QTL localized by our previous work. The 17 SNPsmarker were located chr.2,4,6,9 while 3,6,2,8 SNPs.6.12 candidate genes were found to have important function in the resistance pathway by gene function analysis. They were:Grx, Trx, tubby like protein, ARF27, nudix hydrolase 8, protein kinase APK1A, shaggy-related protein kinase, serine/threonine-protein phosphatase PP1, calmodulin binding protein, salicylic acid-induced fragment 1 protein, lipoxygenase 2 (LOX 2)...
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