The plant materials used in this study are common wheat cultivars Lumai No.5, Chinese Spring (CS) and Marquis, Th. ponticum, wheat-Th. ponticum partial amphiploid Xiaoyan763l (2n=8x=56), wheat-Th. ponticum disomic addition lines Shannong31504 and Shannong31505 (coming from the hybrids of Xiaoyan7631 and Lumai No.5) and the selected translocation lines Shannong31504-1 and Shannong31505-1. All the materials were preserved by our own laboratory.
Observation of mitosis and meiosis: Mitosis in root tip cells and meiosis in pollen mother cells were observed in accordance with the method of Kong (1999). Gliadin A-PAGE was carried out according to the methods of Yan (1989). The band patterns in the electrophoresis spectra were determined in the light of the nomenclature of Metakovsky (1991).
DNA extraction and PCR amplification: Genomic DNA was extracted from 2 week-old plants following the method of Sharp (1998). DNA concentration was measured by a spectrophotometer, and the DNA was diluted in 1xTE. Decamer oligonucleotide primer, MgCl2, l0xbuffer, dNTP, Taq DNA polymerase were obtained from Sangon Technological Inc. PCR was performed in a 25 μl reaction volume consisting of 2.5μl 10xbuffer, 2 μl 2.5 mM dNTP, 2 μl 25 mM Mg²⁺, 1.2 μl 8 pmol/μl primer, 1.25 U of Taq DNA polymerase, 50 ng template DNA, and an appropriate volume of water to make up the final volume to 25 μl. The reaction mixture was then overlaid with 25 muI of mineral oil (Sigma Chemical Co.) to avoid evaporation. The PCR reaction was run in a Gene Amp 9600 thermocycler for 46 cycles with the first cycle of 94°C for 3 min, 36°C for 1 min, 72°C for 2 min, followed by 45 cycles of 94°C for 15 seconds, 36°C for 30 seconds, 72°C for 1 min. After 46 cycles, there was a final extension step of 4 min at 72°C. The reaction mixture was cooled to 4°C and maintained at this temperature until gel electrophoresis. The PCR products were separated on a 1.2% agarose gel in 1xTAE(Tris-Acetic EDTA) buffer. Forty nanograms of ethidium bromide (EtBr) were added to the gel. A 2 kb DNA ladder was used as a size maker.