剪根和植物生长调节剂对杉木幼苗生长的影响

Effect of root pruning and plant growth regulators on the growth of Cunninghamia lanceolata seedlings

[目的]探究剪根和植物生长调节剂对杉木幼苗生长的影响。[方法]采用L9(3^4)正交设计,研究不同剪根长度(剪去总根长的2/3、1/2、1/3)和3种不同浓度的植物生长调节剂:细胞分裂素(6-BA)、萘乙酸(NAA)和吲哚丁酸(IBA)对杉木幼苗水培生根的影响,并优化生根条件。[结果]剪根处理可增加侧根数,但主根停止生长;不同浓度的6-BA、NAA和IBA对侧根生长的影响不同,但作为生长素信号均可促进植物侧根生根。其中,IBA浓度对侧根数生长无显著影响,但对侧根长生长效果显著。[结论]侧根生根数最优方案为:剪根1/3长度+50 mg·L^-1 6-BA+200 mg·L^-1 NAA;侧根长最优方案为:剪根1/3长度+25 mg·L^-1 6-BA+100 mg·L^-1 NAA+50 mg·L^-1 IBA。

[Purpose]To investigate the effects of root pruning and plant growth regulators on the growth of Chinese fir seedlings.[Method]L9(3^4)orthogonal design was used to study the effects of pruning different length of root(prune 2/3,1/2,or 1/3 of the total root length)and application of three different concentrations of plant growth regulators[cytokinin(6-BA),naphthalene acetic acid(NAA),or indole butyric acid(IBA)]on the rooting of Chinese fir hydroponic culture and optimization of rooting conditions.[Result]Root pruning increased the number of lateral roots,but stopped the growth of primary roots.Different concentrations of 6-BA,NAA,or IBA had different effects on the growth of lateral roots,as auxin signals these growth regulators all promoted the growth of lateral roots.Although IBA concentration had no significant effect on the number of lateral roots,there was a significant effect on the growth of lateral roots.[Conclusion]The optimal treatment for increasing the number of lateral roots is pruning 1/3 of primary root length and applying 50 mg·L^-1 of 6-BA and 200 mg·L^-1 of NAA.The optimal treatment for enhancing lateral root length is pruning 1/3 of primary root length and applying 25 mg·L^-1 of 6-BA,100 mg·L^-1 NAA,and 50 mg·L^-1 IBA.