【摘要】 【目的】探究赤霉素喷洒处理诱导新疆杨产生2n花粉的可行性及其对花粉母细胞微管骨架的影响，旨在开发诱导效果好且价格低廉的新型化学诱变剂，构建高效的林木多倍体育种技术体系。【方法】以新疆杨雄花枝为试验材料，利用醋酸洋红染色法、免疫荧光法等方法，在观察新疆杨花粉母细胞减数分裂进程的基础上，开展了赤霉素喷洒处理诱导新疆杨2n花粉产生及其对花粉母细胞减数分裂微管骨架动态变化的影响研究。【结果】新疆杨花粉母细胞减数分裂历时约4 d，且存在明显的不同步性。减数分裂时期、喷洒次数、减数分裂时期和喷洒次数的交互作用、以及喷洒次数和赤霉素浓度的交互作用均对2n花粉诱导率具有显著影响。利用50μmol/L的赤霉素溶液于第二次减数分裂时期对新疆杨花粉母细胞进行7次喷洒处理是诱导新疆杨花粉染色体加倍的最佳处理组合，2n花粉诱导率达到（8.83±3.10）%。与对照组相比，在最佳处理条件下，新疆杨花粉母细胞末期Ⅱ相邻子核之间的辐射状微管部分缺失，导致2个相邻子核间胞质分裂失败，从而产生核复原现象，形成三分体，进而发育成一个单倍性配子和一个2n配子。【结论】赤霉素喷洒处理可诱导新疆杨花粉染色体加倍，获得一定比例的2n花粉。赤霉素喷洒处理后，花粉母细胞第二次减数分裂末期相邻子核之间的辐射状微管部分缺失可能是赤霉素处理诱导新疆杨产生2n花粉的原因。更多还原

【Abstract】 [Objective] This work was to discuss the feasibility of produce 2n pollen by inducing 2n pollen production via gibberellins(GA3) and investigating the effects on meiotic microtubule cytoskeleton of pollen mother cells(PMCs) in Populus bolleana, leading to developing a more effective and cheaper chemical mutagen and establishing an effective system of polyploidy breeding for forest tree. [Method] The observation of the meiotic process of PMCs, the production of 2n pollen induced by GA3 spraying treatment and its effects on the organization of microtubule were conducted by aceto-carmine(2%) staining and indirect immunofluorescence microscopy using male flower branches as experimental material in P.bolleana. [Result] It took about 4 days to complete the meisois of PMCs, and the meiotic process within different buds was asynchronous. The meiotic stage, spray time, the interaction of meiotic stage × spay time and spay time × concentration of GA3 had significant effects on the induction rates of 2n pollen. The optimal treatment combination for inducing pollen chromosome doubling by 50 μmol/L GA3 solution was given 7time spraying when PMCs were at meiosis Ⅱ. The highest induction rate was(8.83 ± 3.10) %. Compared with the control group, the radial microtubular structures between two neighboring nuclei were under the optimal conditions, lacked in some treated PMCs, leading to the failure of cytokinesis, nuclear restitution and the formation of triad and consequently a haploid gamete and a 2n gamete. [Conclusion] Spraying gibberellin could induce chromosome doubling of P. bolleana pollen and obtain 2n pollen in a certain proportion. After PMCs being treated with GA3, the partial absence of radial microtubular structure between two neighboring daughter nuclei in some PMCs at telophase Ⅱ is found to be responsible for 2n pollen production.更多还原