小麦族中含St染色体组物种的特异分子标记的建立

以拟鹅观草(Pseudoroegneria spicata)、偏凸山羊草(Aegilops ventricosa)、二倍体簇毛麦(Dasypyrum villosum)、荆州黑麦(Secale cereale cv. Jingzhou rye)、普通小麦中国春(Chinese Spring)等15个物种为材料, 用200条10碱基随机引物进行RAPD分析, 筛选到拟鹅观草基因组中1个542 bp的特异DNA片段(GenBank登录号为DQ992032), 命名为OPH11542。根据OPH11542设计特异引物, 对小麦族物种进行PCR扩增, 发现拟鹅观草可以扩增出OPH11542以及分子量分别为742 bp (GenBank登录号为DQ992033, 记为OPH11742)和743 bp (GenBank登录号为EF014218, 记为OPH11743)的DNA片段, 而其他材料均未扩增出这3个片段。经序列比对结合多个软件的分析结果认为该3个片段为同一类新重复序列。利用特异引物对15份含St染色体的物种进行扩增, 发现含StY染色体组的物种均能扩增出OPH11742或OPH11743, 而含StH染色体组的物种均能扩增出OPH11542。这表明St染色体组在与其它染色体组组合形成多倍体的过程中往往会出现不同程度的重组或修饰。OPH11542、OPH11742和OPH11743可以作为检测St染色体的分子标记。

Analysis of St-chromosome-containing triticeae polyploids using spe-cific molecular markers

In this study, random amplified polymorphic DNA (RAPD) analysis was performed on Pseudoroegneria spicata, Aegilops ventricosa, Secale cereale cv. Jingzhou Rye, Dasypyrum villosum and other 11 triticeae materials using 200 ran- dom 10-based primers. A 542 bp specific RAPD fragment (Accession No. DQ992032), named OPH11542, was obtained from Ps. Spicata. Based on the sequence of OPH11542, a pair of sequence characterized amplified region PCR (SCAR-PCR) primers was designed and used to amplify the materials of triticeae. The result demonstrated that 3 specific DNA segments of 542 bp, 742 bp (DQ992033)and 743 bp (EF014218) respectively, were obtained from St chromosome, howerer, these 3 segments were not appear in materials not contain St chromosome. Sequence similarity analysis revealed that these 3 seg- ments were new repeated DNA sequences. SCAR-PCR was also performed on 15 materials containing St chromosome, and the result showed that OPH11742 or OPH11743 was always found in materials containing StY chromosome, whereas OPH11542 in materials containing StH chromosome. These results indicated that, chromosome recombination or modifica- tion often occurred in St chromosome in the course of combination of St and other chromosome to form a polypolid, and OPH11542, OPH11742 and OPH11743 could be used as molecular markers for the detection of St chromosome.