Studies on Suitable Factors for Callus Formation and Differentiation of Mature Embryo in Winter Wheat with High Efficiency

Using the mature embryos of four winter wheat cultivars to be the explants,the effects of pre-treatments of temperature,2,4-D concentrations in callus formation medium,and phytohormone types and their combination in callus differentiation medium on callus formation and differentiation were studied.The results showed that low temperature(4℃) pre-treatment could obviously improve the callus formation rate compared to room temperature pretreatment(25℃).Suitable 2,4-D concentration for callus formation in the callus induction medium was 4 mg/L.The combination of phytohormones of 1 mg/L KT +2 mg/L 6-BA had higher the callus differentiation rate than those in 1 mg/L KT or in 2 mg/L 6-BA,the single type of phytohormone treatment.Under the same culture condition,there were dramatic differences on callus formation and differentiation among the tested cultivars.Thus,low temperature pretreatment,using suitable 2,4-D concentration during the callus induction process,combining the suitable phytohormone combination in callus differentiation are important factors,to improve the callus formation and differentiation,when using the mature embryo to be the plant regeneration explants.