成年雄性毛白杨组培幼化技术研究

Study on tissue culture juvenation technique of male Populus tomentosa Carr.

【目的】毛白杨以无性繁殖为主,而无性繁殖材料往往存在老化现象,严重影响苗木质量,研究繁殖材料的幼化技术对于改善苗木质量,促进无性林业发展有重要意义。【方法】以北京大兴区站上村的200年生雄性毛白杨为对象,取其根萌条为繁殖材料,探索2种灭菌试剂处理条件下,不同灭菌时间对外植体成活与生长的影响,同时在MS培养基中设置不同激素组合研究其增殖的最佳效果,筛选出适合其生长的最佳增殖培养基,通过继代培养研究此200年生成年雄性毛白杨的组培幼化技术。【结果】结果表明,0.1%氯化汞溶液的灭菌效果比10%次氯酸钠溶液效果好,最佳灭菌处理为0.1%氯化汞7 min,成活率为57%;最佳增殖培养基为MS+0.7 mg/L 6-BA+0.01 mg/L NAA,最高丛生芽分化系数为2.23,茎高生长量≥1 cm苗的数量比例为53.33%,显著高于其他处理;随着继代次数的增加,生长周期由63 d(1代)降至44 d(4代),继代培养增殖系数由0.93(1代)提升至4.85(4代),茎高生长量≥3 cm苗的数量比也从2.23%(1代)显著增至62.34%(4代)。【结论】此200年生毛白杨繁殖材料存在一定程度的老化现象,母株的年龄可能影响其根萌条的幼化程度,但随着继代次数的增加,生长势有了显著的提高,说明多次继代培养有较明显的幼化作用,且随着继代次数的增加,幼化效果也越好。

【Objective】Regeneration of Populus tomentosa mainly rely on asexual reproduction,but the material of asexual propagation often has aging phenomenon.【Method】It is important to understand the aging pattern of reproductive material and the juvenation techniques.In this study,200 year old mature trees of male P.tomentosa root sprouts were used as study materials.Two sterilization reagents and sterilization times were used to test the impact on the survival rate and growth of propagules.Different hormone combinations in MS medium were designed to select the best multiplication culture medium according to the effect of propagule proliferation.Juvenation technique of mature P.tomentosa were studied through successive sub-culture.【Result】The results showed that sterilization effect of 0.1%mercuric chloride solution was better than the 10%sodium hypochlorite solution.The best sterilization treatment was 0.1%mercuric chloride in 7 min,the highest survival rate was 57%.The best proliferation medium was MS+0.7 mg/L 6-BA+0.01 mg/L NAA,in which shoot multiplication coefficient was the highest of 2.23,the proportion of shoot number(shoot increment≥1 cm)was 53.33%,they were significantly higher than other mediums.After 4 generations of breeding the growth cycle decreased from 63 days to 44 days,the proliferation coefficient increased from 0.93 to 4.85,the percentage of plant number(shoot increment≥3 cm)significantly increased from 2.23%to 62.34%.【Conclusion】It was indicated that there was an aging phenomenon in this 200 years old P.tomentosa root sprout.The juvenation effect was much obvious after multiple sub-cultures.