【摘要】 【目的】建立银白杨(Populus alba)下胚轴高频再生体系,为银白杨遗传转化和推广利用奠定基础。【方法】以银白杨下胚轴为外植体,通过器官发生途径诱导形成不定芽,探讨苗龄、接种方式及不同植物生长调节剂、硝酸银和蔗糖质量浓度等对银白杨下胚轴不定芽分化和生根的影响。【结果】适宜银白杨下胚轴不定芽分化的最佳培养基为:MS+AgNO33.5 mg/L+蔗糖35 g/L+琼脂6.0 g/L+IBA 0.3 mg/L+TDZ 1.5 mg/L,用该培养基培养银白杨下胚轴外植体,其分化率为98.63%,平均每个外植体形成的不定芽为23.81个。银白杨下胚轴外植体不定芽未经愈伤组织而直接产生于下胚轴的表皮或近表皮等表层细胞。3~7 d苗龄银白杨下胚轴诱导不定芽分化能力无显著差异,诱导率均达到95%以上,7 d后随着苗龄的增加,不定芽分化、诱导能力快速下降,苗龄为11 d时不定芽分化率只有52.28%。不同切段下胚轴不定芽再生能力由强到弱表现为:上部切段(靠近子叶端的下胚轴部分)>中部切段>下部切段。以正插(形态学下端插入培养基)方式接种的外植体不定芽再生能力显著大于反插(形态学上端插入培养基)和平放的。【结论】优化了银白杨的组织培养体系,初步找到了影响银白杨下胚轴诱导分化及植株再生的主要因子。更多还原

【Abstract】 【Objective】 This paper established a high efficient plant regeneration from Populus alba hypocotyl,laying a sound foundation for genetic transformation and extension application of Populus alba.【Method】 An efficient plant regeneration protocol for Populus alba achieved via organogenes from callus tissues formed on hypocotyl explants in vitro.In this paper,the effects of seedling age,inoculation method,different plant growth regulators,AgNO3 and sucrose etc on hypocotyl of Populus alba bud differentiation and rooting were investigated.【Result】 The results showed best bud differentiation and bud multiplying medium:MS+AgNO3 3.5 mg/L+sucrose 35 g/L+agar 6.0 g/L+IBA 0.3 mg/L+TDZ 1.5 mg/L,was sifted,with bud differentiation rate of 98.63% and the average shoot number regenerated per explant was 23.81,and that there was on intervening callus phase for shoot regenerated directly from hypocotyl explants.There was no significant difference among hypocotyl of 3 to 7-day seedling in their shoot regeneraiton frequency which were above 95% respectively.The aging of seedlings resulted in a reduction of shoot regeneraiton frequency,which was only 52.28% with 11-day-old seedlings.The order of shoot regeneration ability of hypocotyl segments from different positions was:the upper>the middle>the lower.Hypocotyls inoculated with their abaxial ends up were more effective in shoot regeneration than those either inoculated with their abaxial ends down or placed horizontally.【Conclusion】 The in vitro system of Populus alba was optimized and the main factors affecting Populus alba hypocotyl induction bud differentiation and regeneration were primarily traced.更多还原