[Analysis of St-chromosome-containing triticeae polyploids using specific 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 random 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, however, these 3 segments were not appear in materials not contain St chromosome. Sequence similarity analysis revealed that these 3 segments 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 modification 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.