Molecular cytogenetic characterization of the amphiploid between bread wheat and Psathyrostachys huashanica

A new wheat-Psathyrostachys huashanica amphiploid, PHW-SA, was characterized using molecular cytological tools to evaluate the potential utilization of P. huashanica for wheat improvement. PHW-SA pollen mother cells (PMCs) regularly revealed averagely 0.57 univalents, 24.51 ring bivalents, 3.19 rod bivalents and 0.01 trivalents per cell. Complete homologous chromosome pairing was seen in 81% of the PMCs, indicating a degree of cytological stability. P. huashanica C-banding karyotypes of PHW-SA displayed strong heterochromatin terminal bands at either or both ends. 24 P. huashanica chromosome arms showed telomeric bands. Using P. huashanica DNA as a probe and J-11 DNA as blocker, distinctive P. huashanica chromosomes, which were presented entirely greenish-yellow hybridization signals, were observed in a somatic metaphase of PHW-SA. GISH also revealed the chromosomal breakage and translocation occurring in the amphiploid PHW-SA, which may represent a centromeric fusion between P. huashanica and wheat chromosomes. Seeds storage proteins electrophoresis indicated that PHW-SA expressed some of P. huashanica specific gliadin and glutenin bands, and a few gliadin and glutenin bands of the parents disappeared and new bands appeared. The results indicated that the amphiploid PHW-SA could serve as novel germplasm sources for wheat improvement.