Abstract:

The resistance gene of powdery mildew was introduced from Haynaldia villosa into common wheat (Triticum aestivum) and located on 6VS and designed as Pm21. In order to precisely map and clone Pm21, more molecular markers and chromosome structural variants need to be developed. RGA and STS markers, usually from expressed sequences, have proved to be very effective DNA markers. In order to development and application of molecular markers specific to chromosome 6VS of H. villosa, the DNA polymorphic analysis was performed on common wheat Yangmai 5, H. villosa and wheat-H. villosa 6VS/6AL translocation lines with 11 RGA and 17 pairs of STS primers. Two polymorphic fragments, about 1 000 bp and 800 bp, were amplified by a RGA primer Pto kin4 and a pair of STS primer, and then were cloned and sequenced, respectively. Based on the cloning sequences, two pairs of specific markers, CINAU17-1086 and CINAU18-723, were developed, and used to amplify common wheat Chinese Spring, Yangmai 5, Yangmai 158, H. villosa and T. durum-H. villosa amphiploid, wheat-H. villosa alien addition lines (1V-7V), wheat-H. villosa 6VS/6AL translocation line 92R137. The results indicated that two markers, CINAU17-₁₀₈₆ and CINAU18-₇₂₃, were located on chromosome 6VS because only the materials with 6VS chromosome could amplify the specific patterns. Furthermore, CINAU17-₁₀₈₆ was located between FL0.58 and FL0.70 and CINAU18-₇₂₃ between FL0.45 and centromere on chromosome 6VS by using 6VS deletion addition lines and translocation lines. The results obtained from these two markers were consistent with those from the cytogenetic identification to variant materials of chromosome 6VS obtained by radiating pollen. Therefore, CINAU17-₁₀₈₆ and CINAU18-₇₂₃ markers could be used to rapidly detect the correspondent chromosome segments of 6V in common wheat and primarily identify the breakage points of deletion lines.

Key words: Haynaldia villosa, Resistance gene analog (RGA), Site tagged sequence (STS), Chromosome-specific molecular marker, Deletion line