基于外植体生理复幼的麻栎茎段无菌离体培养

In Vitro Sterile Culture of Nodal Segments Based on Explants Phy⁃siological Rejuvenation in Quercus acutissima

以离体休眠枝条复幼处理后的萌芽茎段为外植体,开展20年生成龄麻栎的离体再生影响因素研究。结果表明:初代培养,以1/2 MS+3.0 mg/L 6-BA+2.0 mg/L KT+0.2 mg/L IBA为优选培养基,不定芽诱导率可达69.70%;继代培养,以1/2 MS+2.0 mg/L 6-BA+2.0 mg/L KT+0.2 mg/L IBA为优选增殖培养基,芽增殖系数约为2.0,但茎尖死亡率高,影响不定芽的连续继代。在影响继代苗茎尖死亡率的各试验因素中,培养基种类、继代转接时间、培养基中氯化钙浓度、硼酸浓度对继代培养中不定芽茎尖死亡率均有显著影响。WPM培养基中,继代培养23 d,硼酸质量浓度为12.4 mg/L,茎尖死亡率最低(13.06%)。在改良WPM+0.3 mg/L IBA+0.2 mg/L NAA的培养基上,成龄麻栎继代苗生根率最高(19.91%)。本试验为麻栎树种改良及无性快繁奠定了基础。

The influence factors of 20⁃year⁃old Quercus acutissima in vitro regeneration were studied by using the bud segments of dormant branches after rejuvenation as explants.The results showed that the adventitious bud induction rate was 69􀆰70%in the primary culture medium with 1/2 MS+3􀆰0 mg/L 6⁃BA+2􀆰0 mg/L KT+0􀆰2 mg/L IBA.In the subcul⁃ture,1/2 MS+2􀆰0 mg/L 6⁃BA+2􀆰0 mg/L KT+0􀆰2 mg/L IBA was used as the optimal proliferation medium,and the bud proliferation coefficient was about 2􀆰0􀆰However,the shoot tip mortality was also high,which affected the continuous subculture of adventitious buds.Among the experimental factors affecting the shoot tip mortality in subculture,the medi⁃um type,subculture transfer time and the concentration of CaCl2·2H2 O and H3 BO3 in the medium all had significant effects on the shoot tip mortality of adventitious buds in the subculture.When the H3 BO3 content was adjusted to 12􀆰4 mg/L in the modified WPM medium,the mortality rate of shoot tip was the lowest(13􀆰06%)after 23 d subculture.The rooting rate of buds was the highest(19􀆰91%)on modified WPM+0􀆰3 mg/L IBA+0􀆰2 mg/L NAA medium.The experi⁃ment laid the foundation for the improvement and asexual propagation of Quercus acutissima.