用于区别不同棉花品种基因组特征的微卫星位点筛选

保守性强、重复性好、多态性高的微卫星位点可被有效用于构建作物DNA条形码。选取目前生产上主要推广种植、代表不同来源系统的12个棉花品种作为微卫星位点筛选材料，参考我室构建的四倍体栽培棉种种间高密度遗传图谱信息，从376对覆盖全基因组的SSR引物中，筛选出51对引物可扩增出带型清晰且多态性高的微卫星位点。这些引物在12个供试品种中共产生155个等位位点，每对引物揭示的等位基因位点在2~7之间，平均值为3.04。参照微卫星位点的染色体定位和多态信息，在每条染色体上选择一个多态性相对高的SSR位点，其相应的26对SSR引物被推荐为构建棉花品种DNA条形码的一套首选引物，并初步应用于12个品种的DNA条形码编制。其余25对引物作为候选引物。使用该套引物扩增出的微卫星位点可用于大量棉花品种DNA条形码构建，为棉花品种真实性和纯度的分子鉴定奠定基础。

Screening of Microsatellite Loci for Identifying Genome Barcoding of Cotton Cultivars

Microsatellites or simple sequence repeats (SSRs) loci with high information content, reproducibility and locus specificity can be used effectively to construct DNA barcode in plant. In this study, 12 cotton cultivars derived from different germplasm pedigrees and planted widely in three ecological cotton growing areas were selected to screen the SSR loci with high polymorphism. Based on our newly updated high-density genetic linkage map from G. hirsutum×G. barbadense BC 1 mapping population, we selected 51 primer pairs with clear amplification products and high polymorphism from 376 genome-wide SSR primer pairs. In total, 155 polymorphic loci in 12 cultivars were produced by using the selected 51 primer pairs. Alleles ranging from two to seven with an average of 3.04 were detected by each SSR primer pair. Of them, 26 SSR primer pairs, which amplified SSR loci were tagged on corresponding 26 chromosomes in cultivated tetraploid cotton species, were recommended as first selected primer pairs to establish DNA barcode of cotton cultivars, and other 25 SSR primer pairs could be used as candidate primer pairs. DNA barcodes of 12 cultivars were further constructed effectively using these microsatellite loci with high polymorphism. In the future, these microsatellite loci can be used to construct DNA barcode for a large number of cotton varieties, and applied effectively in the identification of genuineness and purity in cotton cultivar seeds.