Abstract: Calli were induced from the young leaves and mature embryos of seven wheat-wheatgrass alien additional lines, and somaclones were established from the calli. A large number of plantlets were obtained and survived after transplantation. The medium WG used for tissue culture of wheat-wheatgrass alien addition lines was set up in the experiment. The methods induced callus with two kinds of media were used. The first medium WG2 supplemented with 4 mg/l 2, 4-D and l mg/l NAA was used for callus formation. The second medium was WG2 with 2 mg/l 2, 4-D, 0.5 mg/l NAA and 0.25 mg/l KT. Differentiation medium used was WG3 with 0.5 mg/l KT, 1mg/l NAA and 100 mg/l adenylic acid. The examination of the chromosomes in regenerated plants indicated that the chromosomal number variation was remarkable. The plants maintaining 2n=44 were only 34.4% of the total regenerated plants, and the plants with the chromosomal number returned to 2n=42 made a relatively greater part of the variational plants regenerated. About half of the regenerated plants showed morphological variations. The crossover, translocation and other chromosomal structural changes were found in PMCs of the variational plants regenerated. Meanwhile, the polycentric chromosome derived from the fusion of several chromosomes and chiasmata of somatic chromosomes were clearly observed in callus cells, indicating that crossover and translocation occurred in somacloaes.

Key words: Wheat-Wheatgrass Alien Addition Lines, Somaclones, Variation