Abstract:

To investigate the effects of carbon (C) ion beam treatment on the tissue culture of wheat immature embryos and the somaclonal variation in their progeny, and to provide a reference for increasing the variation frequency of wheat somatic clones to address germplasm scarcity and accelerate new cultivar breeding, this study was conducted. Using the pure-line seed 15-676, which exhibits excellent agronomic traits but relatively tall plant height, immature embryos were treated with a carbon ion beam at a radiation dose of 80 Gy and then subjected to tissue culture. Untreated tissue-cultured embryos served as the control. The induction frequency, differentiation frequency, variations in major agronomic traits in the M₂S₁ and S₁ generations, and the glutenin subunit composition were systematically examined. The results revealed that the differentiation frequency in the carbon ion beam-treated group was 11.6%, which was significantly lower than that in the control group (20.6%). In the M₂S₁ generation, the plant height in the carbon ion beam-treated group decreased by 11.74 cm compared to the control, a difference that was highly significant. Meanwhile, the treated group demonstrated increases in the number of grains per main spike, grain weight per main spike, and grain weight per plant. Additionally, both the M₂S₁ and S₁ progeny grains retained the same high-quality glutenin subunits (5+10) as the original 15-676 variety. In conclusion, the combination of carbon ion beam treatment with tissue culture can effectively enhance the level of genetic variation in somatic clones, thereby expanding screening opportunities for beneficial mutants and providing abundant genetic materials for wheat germplasm innovation and new variety breeding.

Key words: heavy ion, carbon ion beam, wheat, radiation, mutagenesis, tissue culture, glutenin