Abstract:

Thinopyrum bessarabicum Löve and Chinese Spring-Thinopyrum bessarabicum amphiploid (the amphiploid hereafter) are reported with high salinity tolerance. Screen of molecular markers tagging different chromosomes of Thinopyrum bessarabicum would facilitate transfer of these genes or chromosomes into common wheat. Some specific proteins or enzymes, AFLP or RAPD markers have been described by different authors. However, use of SSR, STS, and RFLP markers identifying Thinopyrum bessarabicum chromosomes is seldom reported. To dig out the beneficial genes of this species, the amphiploid was introduced from Dr. Mujeeb-Kazi, CIMMYT, and several additions, and translocations have been independently developed and reported by Cytogentics Institute, Nanjing Agricultural University, China. Using SSR, STS, and RFLP markers of wheat and barley etc, 7 disomic additions, 3 alien lines including translocations and additions and 1 multiple additions were characterized in this study. The results revealed that 14 of 219 wheat SSRs, 8 of 126 barley STS and 2 wheat STS, 6 RFLP probes could be used to distinguish the chromosomes of Thinopyrum bessarabicum added in wheat. Of the alien chromosome lines, C7-17 and C7-17-2 were verified involving chromosome 1J encoding specific HMW-Glu subunit of Thinopyrum bessarabicum. Two STS markers MWG2303 (2HL) and NAU/Xibao15 (6S), one RFLP probe BCD135 (2BL) and 4 SSR markers (Cfd168 (2A), Xgwm526 (2B), Xgwm311 (2D), and Xgdm93 (4B)) could be used to tag the chromosomes added in CH05, while 6L probe PSR154 and one wheat 2AL-end STS KsuH9 failed to produce polymorphism indicating rearrangements occurred in this chromosome, therefore, the preliminary designed J3 based on the C-banded karyotype of Thinopyrum bessarabicum added in this line was deduced with closer relationship with group 2 chromosomes of wheat. Two STSs from 3HL（BCD269, MWG974）, one probe PSR116 from wheat 3L and one SSR Xgwm114(3DS) could be used to tag the chromosomes added in CH09, the preliminary designed J7 was then deduced with closer relationship with group 3 chromosomes of wheat. One STS MWG808(7H), one probe mapped in the middle part of 4L(PSR163) and one SSR Xgdm131(3B) could be used to tag the chromosomes added in CH03，CH04 and CH34, while two other probes mapped in the distal part of 4L (WG114) and 4S(CDO669) without RFLPs, indicating these three additions might contain the same alien chromosomes, the preliminary designed J1, J2, and J? in these lines respectively were deduced with closer relationship with group 7 chromosomes of wheat, rearrangements with group 4 chromosomes also involved. Three SSR markers Xgdm35 (2D), Xgwm515 (2A, 2D), and Xgwm614 (2A, 2B, and 2D) could be used to tag the large segmental translocation chromosomes added in CH12, and small segmental translocation chromosomes contained in CH11 which also included another pair of alien chromosomes similar to that of CH05, this result indicated that these translocations with different segments might be derived from the same chromosome of Thinopyrum bessarabicum. 13 markers (5 barley STSs, 3 RFLP probes and 5 wheat SSRs) could be used to trace the chromosomes not involved in the present lines.

Key words: Triticum aestivum L., Thinopyrum bessarabicum Lö, ve, SSR, STS, RFLP, HMW-Glu