Different Methods Of Tuber Mustard Regeneration And Its Genetic Stability Analysis

Tuber mustard is one of the special vegetables in China, and itsproduct--preserved szechuan pickle is also very famous in the world. Efficientplant regeneration of tuber mustard through different methods is necessary to basic theoretical research and practical application. Furthermore, genetic stability analysis of the regenerants through different plant regeneration methods is essential for germplasm preservation and improvement.In the present study, we obtained regenerated plants of cytoplasmic male sterile (CMS) tuber mustard through different methods including direct and indirect organogenesis from cotyledon, and shoot prolongation of apical buds or axillary buds. Meanwhile, we analyzed the genetic stability of the callus during the indirect regeneration method, as well as some of the plantlets regenerated through different methods.Results were showed as follows:(1) The regeneration system of tuber mustard through callus induction followed with shoot differentiation from cotyledon was established. When the cotyledon of tuber mustard was cultured on the MS medium containing with NAA, BA and 2, 4-D, the callus generated, the callus could be induced with high quality when the cotyledon was cultured on the MS medium containing with 0.25 mg·L-1 NAA, 0.5 mg·L-1 BA and 0.25 mg·L-1 2, 4-D. The callus was differentiated hardly on the MS medium containing 1-2 mg·L-1 BA and 0.2 mg·L-1 NAA with a frequency of 8.3%. However, it was improved to be 52.4% when the cefotaxime or carbenicillin was added into MS medium containing 1-2 mg·L-1 BA and 0.2 mg·L-1 NAA.(2) The regeneration system of mustard through adventitious induction from cotyledon was established. The regeneration ratio was 100% when the explants were induced on the MS medium supplemented with 3.0 mg·L-1 BA and 0.05mg·L-1 NAA, as well as the highest number of the shoots from a piece of cotyledon cultured on this medium.(3) The "shoot from nodal segment" method of regeneration system was established. The results indicated that the number of the shoots from the nodal segments was increased with the concentrations of BA in the medium. However, the vitricus shoots were increased with the concentrations of BA. Then this method was successfully applied on tuber mustard breeding for reducing the hollowness.