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báo cáo khoa học: " Association mapping of common bacterial blight resistance QTL in Ontario bean breeding populations"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Association mapping of common bacterial blight resistance QTL in Ontario bean breeding populations | Shi et al. BMC Plant Biology 2011 11 52 http www.biomedcentral.com 1471-2229 11 52 BMC Plant Biology RESEARCH ARTICLE Open Access Association mapping of common bacterial blight resistance QTL in Ontario bean breeding populations Chun Shi1 Alireza Navabi1 2 and Kangfu Yu1 Abstract Background Common bacterial blight CBB incited by Xanthomonas axonopodis pv. phaseoli Xap is a major yield-limiting factor of common bean Phaseolus vulgaris L. production around the world. Host resistance is practically the most effective and environmentally-sound approach to control CBB. Unlike conventional QTL discovery strategies in which bi-parental populations F2 RIL or DH need to be developed association mappingbased strategies can use plant breeding populations to synchronize QTL discovery and cultivar development. Results A population of 469 dry bean lines of different market classes representing plant materials routinely developed in a bean breeding program were used. Of them 395 lines were evaluated for CBB resistance at 14 and 21 DAI Days After Inoculation in the summer of 2009 in an artificially inoculated CBB nursery in south-western Ontario. All lines were genotyped using 132 SNPs Single Nucleotide Polymorphisms evenly distributed across the genome. Of the 132 SNPs 26 SNPs had more than 20 missing data 12 SNPs were monomorphic and 17 SNPs had a MAF Minor Allelic Frequency of less than 0.20 therefore only 75 SNPs were used for association study based on one SNP per locus. The best possible population structure was to assign 36 and 64 of the lines into Andean and Mesoamerican subgroups respectively. Kinship analysis also revealed complex familial relationships among all lines which corresponds with the known pedigree history. MLM Mixed Linear Model analysis including population structure and kinship was used to discover marker-trait associations. Eighteen and 22 markers were significantly associated with CBB rating at 14 and 21 DAI respectively. Fourteen markers were .