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Abstract

The wheat-Thinopyrum amphiploid 'Agrotriticum # 3425' (AT 3425), which is highly resistant to Cephalosporium stripe, was identified to carry seven pairs of Thinopyrum chromosomes, three pairs of wheat-Thinopyrum translocated chromosomes and 18 pairs of wheat chromosomes. Fluorescence genomic in situ hybridization (FGISH), C-banding, sequential C-banding and FGISH, and denaturing polyacrylamide gel electrophoresis (SDS-PAGE) were used to characterize and identify the chromosomes. The Thinopyrum chromosomes in AT 3425 were designated as T1 through T7 based on their C-banding patterns. The FGISH and C-banding patterns of mitotic chromosomes in AT 3425 and meiotic chromosomes in the hybrid between AT 3425 and wheat cultivar 'Chinese Spring' (CS) revealed that wheat chromosomes 1D, 2B and 3D were involved in the three wheat-Thinopyrum chromosome translocations designated as (W-T)1, (W-T)2, and (W-T)3 respectively. The analysis of high-molecular-weight glutenin subunits in single seeds of AT 3425 confirmed the involvement of wheat chromosome 1D in the translocation (W-T)1. The designations 1DSx1DL-1TL, 2BSx2BL-2TL and 3DSx3DL-3TL were suggested for the wheat-Thinopyrum translocated chromosomes (W-T)1, (W-T)2 and (W-T)3 in AT 3425 respectively.

A Genomic Comparison of Homoeologous Recombinants of the Lr19 (T4) Translocation in Wheat

“…FGISH was performed as described by Cai et al (1998). The first was a primary recombinant (Lr19-149) from an earlier study which resulted from a homoeologous crossover between the T4 translocation (7DL) and wheat chromosome 7B.…”

“…Hybridization of the probe DNA to chromosomes and signal detection were conducted following the procedures of Cai et al (1998). ponticum leaves, quantified and labeled with Biotin-16-dUTP via nick translation (Bioprobe Nick Translocation Kit, Enzo Life Sciences International, Inc., Plymouth Meeting, PA, USA) to be used as a probe for hybridization with mounted chromosomes.…”

“…DNA extraction, quantification, polymerase chain reaction (PCR) amplification, and electrophoresis were performed according to Cai et al (1998) with minor modifications to the amplification and electrophoresis procedures. DNA extraction, quantification, polymerase chain reaction (PCR) amplification, and electrophoresis were performed according to Cai et al (1998) with minor modifications to the amplification and electrophoresis procedures.…”

“…Each translocation occurs in homozygous condition in a CS wheat genetic background . FGISH was performed as described by Cai et al (1998). Seeds of the translocation stocks were germinated in Petri dishes at room temperature for 3 d. Approximately 2.5-cm root tips were cut and pretreated in ice water (0-4°C) for 20 h. This was followed by fixation in 3:1 ethanol/acetic acid for another 2 d at room temperature.…”

“…Genomic DNA of CS was sheared in 0.4M NaOH in boiling water for 40 to 50 min for use as blocking DNA. Hybridization of the probe DNA to chromosomes and signal detection were conducted following the procedures of Cai et al (1998). Fluorescein isothiocyanate-conjugate (FITC-Avidin) was used with VECTA-SHIELD antifading medium to detect the signal and propidium-iodide (Vector Laboratories Inc., Burlingame, CA, USA) to counterstain the chromatin.…”