Optimization of mature embryo-based high frequency callus induction and plant regeneration from elite wheat cultivars grown in China

We have developed an efficient procedure for plant regeneration of elite wheat cultivars using mature embryos. Firstly, we established the optimal combination of basal media, inoculation method and pretreatment method using biostatistical methods. The results indicated that the combination of MS medium and longitudinally bisected mature embryos showed the highest culture efficiency, whereas the pretreatment method had no significant effects on callus induction or plant regeneration. A 70% primary callus induction rate was achieved on MS medium containing 2 mg/l 2,4‐d for all tested cultivars. Primary calli were then transferred onto the subculture medium to initiate embryogenic calli. Supplementation of the subculture medium with the appropriate combination of phytohormones (2.0 mg/l 2,4‐d , 0.5 mg/l BA and 0.1 mg/l NAA) significantly enhanced embryogenic callus production. The addition of AgNO₃ (10 mg/l) in regeneration medium promoted plant regeneration, whereas CuSO₄ stimulated root formation. The use of this protocol achieved successful plant regeneration in eight tested cultivars. The culture efficiency ranged from 15.3% to 36.8%, suggesting this regeneration system may be an effective alternative for wheat genetic transformation.