利用直接测序法开发小叶杨抗逆转录因子基因内一套新的核基因组SSR标记.通过对3个抗逆转录因子共21个成员在36个小叶杨基因型个体中的序列比较分析后共检测到31个SSR多态性位点,SSR出现的频率为1/1 916 bp.在小叶杨自然群体中,SSR多态性位点的碱基重复呈现出2～5碱基形式,基元重复次数变异范围为3～20次,其中以二碱基重复的位点较多,占总数的51.6％.在此基础上,依据SSR位点两侧的保守序列,设计31对SSR位点PCR扩增引物对.利用设计的引物检测所开发的SSR位点在杨属内22个基因型个体中PCR扩增的有效性及SSR位点的保守性.PCR扩增结果显示,93.5％的SSR位点能够在杨属内至少4个派内有效扩增,每对引物组合可检测到SSR多样性位点数3～ 12个,平均6个.基于抗逆转录因子基因内开发的SSR标记位点为分子标记辅助小叶杨抗逆性状育种提供工具.%In this study, a set of new polymorphic nuclear SSR markers were developed and characterized in Poptdus simonii by directly sequencing transcription factor genes expressed under abiotic stresses. A total of 31 polymorphic SSR loci were identified in 21 genes of 3 transcription factor families from 36 unrelated individuals of P. simonii. In the polymorphic SSR loci, there were di-, tri-, tetra-, and penta-nucleotide repeats, and 3-20 motifs repeats, with dinucleotide SSRs being the most frequent, accounting for 51.6% of the total loci in the natural population of P. simonii. Thirty-one primer pairs for PCR amplification SSR loci were designed according to the conservative flanking sequences of SSR loci. The utility and conservation of SSR loci were tested with 22 genotypic individuals in genus Populus The PCR amplification exhibited an average of 93. 5% conservation within at least four Sections under genus Populus, and the number of the detected polymorphic alleles ranged from 3 to 12, with an average of 6.0 alleles per locus. The developed gene-based SSR markers of the abiotic stress resistant transcription factor could provide a powerful tool for marker-assisted breeding of new germplasms with desirable abiotic stress resistance in P. simonii, and would have theoretical and practical significance in tree breeding.
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