Dicamba and Sugar Effects on Callus Induction and Plant Regeneration from Mature Embryo Culture of Wheat

To establish a highly efficient plant regeneration system for wheat genetic transformation, the effects of three different concentrations of dicamba and two different sugar types on callus induction and plant regeneration from mature embryo cultures were evaluated. Callus induction and plant regeneration were obtained from mature embryos of two commercial cultivars Zhoumai 18 and Yumai 34 (Triticum aestivum L.) cultured on L3 basal medium. The results showed that the efficiency of mature embryo culture was significantly influenced by the genotypes, sugar types and dicamba concentrations. 4 mg L−1 dicamba proved the best effective for inducing embryogenic callus and also gave the highest proportion of plants regenerated across the two cultivars. Substitution of maltose by sucrose significantly improved the plant regeneration efficiency in both cultivars. There was a significant interaction between genotype-by-sugar types, and sugar types-bydicamba concentrations. Overall, Zhoumai 18 gave the highest frequency of plant regeneration (82.65%) when dicamba concentration was 4.0 mg L−1 and with sucrose in initial callus induction. These results will facilitate genetic transformation work with elite wheat.