Establishing rapid and efficient plant regeneration for poplar 741 through cluster seedling differentiation

Improving the regeneration efficiency of poplar trees is an important role in their genetic transformation. In this study, a regeneration system of 741 poplar tree, a hybrid descendant of Populus alba, was developed through cluster seedling differentiation. By utilizing different hormone concentrations and their combinations to induce callus tissue, cluster seedling formation, and cluster seedling stem extraction, the regeneration system of 741 poplar planting plants was optimized. The optimized concentration and combination of induced callus culture hormones is 1.0 mg/L 6-BA+0.2 mg/L NAA, that of cluster seedlings differentiation is 0.5 mg/L 6-BA+0.1 mg/L NAA, and that of stem extraction is 0.3 mg/L 6-BA+0.05 mg/L NAA. In addition, compared with normal photoperiod, it was found that continuous dark cultivation of tender leaves for 7 days and of petioles for 5 days significantly increased the induction rate of callus tissue. In summary, we established an efficient regeneration system for 741 poplar via cluster seedling differentiation involved in hormone level and combination optimization, photoperiod regulation, and sucrose concentration screening, which provides assurance for genetic transformation of poplar.