激素浓度组合对成熟油梨枝条伸长和生根的影响

Effects of Hormone Concentration Combinations on Branch Elongation and Rooting in Mature Avocado

为了建立抗根腐病成熟油梨砧木的快繁技术体系,通过设置不同浓度(0.1、0.5、1.0、1.5、2.0、2.5、3.0 mg/L)的细胞分裂素(meta-topolin,MT)与不同浓度(0.1、0.5、1.0、1.5 mg/L)的赤霉素(gibberellin,GA3)的组合试验,研究适宜于成熟油梨外植体伸长的培养条件;同时设置不同浓度(0.5、1.0、1.5、2.0、2.5、3.0 mg/L)的吲哚-3-丁酸(indole-3-butyric acid,IBA)的生根培养基,探究最适油梨外植体生根的培养条件。研究发现,伸长试验30 d时(D30)油梨外植体株高增量和茎粗增量的效应量依次是MT浓度×GA_(3)浓度>MT浓度>GA_(3)浓度;对D30叶片增量的效应量依次是MT浓度>MT浓度×GA_(3)浓度>GA_(3)浓度。结果表明,在该研究的测试范围内,最适于伸长的激素浓度组合是MT 2 mg/L、GA_(3)(0.5~1.0)mg/L,而在测试的IBA浓度范围内均没有观察到根系的生长。通过显微结构观察发现,MT浓度为1 mg/L处理的油梨外植体茎木质部(木质部厚度为171.6μm)生长优于MT浓度为0.1 mg/L的处理(木质部厚度为95.3μm),这对后期的成功驯化有一定积极作用。本研究结果可为成熟油梨快繁体系建立提供借鉴。

This experiment was conducted to investigate the suitable culture conditions for the elongation of mature oil pear explants by combining cytokinin(meta-tooling,MT)at different concentrations(0.1,0.5,1.0,1.0,and 1.5 mg·L^(-1))and gibberellin(GA_(3))at various concentrations(0.1,0.5,1.0,and 1.5 mg·L^(-1))to study the culture conditions suitable for the elongation of mature avocado explants to establish a fast breeding technology system for root rot-resistant mature oil pear rootstocks,and at the same time,rooting media with different concentrations(0.5,1.0,1.5,2.0,2.5,and 3.0 mg·L^(-1))of indole-3-butyric acid(IBA)were used to determine the optimal culture conditions for the rooting of avocado explants.We investigated the most suitable culture conditions for the rooting of avocado explants.The effects of the elongation test for 30 d(D30)on the increase in plant height and stem thickness of avocado explants were in the order of MT concentration×GA_(3)concentration>MT concentration>GA_(3)concentration,and the effects on the increase in leaf blades of D30 were in the order of MT concentration>MT concentration×GA_(3)concentration>GA_(3)concentration.The most suitable hormone concentration combinations for elongation in the tested range of this study were 2 mg·L^(-1)MT and 0.5-1.0 mg·L^(-1)GA_(3),and no root growth was observed in any of the tested IBA concentration ranges.Microstructural observation revealed that the stem xylem of oil pear explants treated with an MT concentration of 1 mg·L^(-1)(with a xylem thickness of 171.6μm)grew better than that of plants treated with an MT concentration of 0.1 mg·L^(-1)(with a xylem thickness of 95.3μm),indicating that MT had a positive effect on successful domesti-cation at a later stage.The results of this study can be helpful for future fast propagation systems for mature avocado estab-lishment.