低温和植物生长调节剂处理对菘蓝抽薹开花的影响

Effects of Low Temperature and Plant Growth Regulator on Bolting and Flowering of Isatis indigotica

【目的】探讨温度和植物生长调节剂对菘蓝生长以及抽薹开花的影响,为进一步阐明菘蓝抽薹开花的调控机制提供依据。【方法】以中青一号菘蓝种子为试验材料,在人工气候箱中对菘蓝幼苗进行2、4、6℃低温春化处理,研究低温春化对菘蓝抽薹性状的影响,同时在25℃和4℃条件下测定菘蓝茎尖内源激素的变化以及赤霉素和烯效唑对菘蓝抽薹率的影响。【结果】(1)低温处理可促进菘蓝抽薹、开花和花芽分化,4℃春化处理40 d的幼苗在定植后27 d,12片叶时开始开花,比2℃处理和6℃处理的植株平均提前了4个节位;(2)茎尖内源激素含量分析表明,低温处理增加菘蓝茎尖中3-吲哚乙酸(IAA)、赤霉素(GA)和脱落酸(ABA)的含量,低温和25℃处理下菘蓝IAA含量和GA缓慢上升后下降,IAA含量在出苗后40 d达到最高值,GA含量出苗后50 d左右,且抽薹后IAA和GA含量低于抽薹前,ABA含量在整个生长季节持续增加;(3)低温和GA协同处理的植株表现出加性正效应,低温加速了菘蓝的抽薹、开花进程,这种促进不仅通过在茎尖诱导产生GA,还通过低温与激素之间的相互作用;烯效唑处理显著降低了菘蓝的抽薹率,而GA则可以打破这种抑制。【结论】低温春化促进菘蓝抽薹和开花,低温处理提高了GA、IAA和ABA的含量,外源GA处理可代替低温处理诱导植物在缺乏低温的条件下开花,而GA合成抑制剂烯效唑的作用相反。

【Objective】Effects of low temperature and plant growth regulator on the growth,bolting,and flowering of Isatis indigotica plants were investigated.【Method】Seeds of Isatis.indigotica Zhongqing No.1 were exposed to 2,4,or 6℃in a climate-controlled chamber for vernalization to observe the bolting and flowering of the emerged seedlings.Endogenous hormones in the shoot apex and effects of gibberellin and uniconazole on the bolting rate of the plants under 25℃and 4℃were determined.【Result】(1)Low temperature vernalization promoted the process of bolting,flowering,and bud differentiation of the plants.The seedlings emerged from a 40 d/4℃vernalization began to flower at 27 d after planting,which had 12 leaves on a plant.and It’s 4 nodes earlier than that of 2℃or 6℃vernalization.(2)The low temperature treatment increased the contents of IAA,GA,and ABA in the seedling stem tips.and under 4℃and 25℃treatment,the IAA and GA content slowly increased and followed by a decline,IAA peaked 40 d after germinating,while GA 50 d,and the IAA and GA content was lower than that before bolting,while ABA continued to rise throughout the growing season.(3)The combined low temperature and GA treatment showed additive positive effect,and which accelerated the plant bolting and flowering,not only due to the GA induction at the stem tip but also the interaction between low temperature and hormone.Uniconazole treatment significantly reduced the bolting rate of Isatis indigotica,while GA could break this inhibition【Conclusion】Low temperature vernalization promotes bolting and flowering of Isatis indigotica.It promoted the GA,IAA,and ABA generation in the seedlings.Exogenous GA could induce flowering of the plants without a low temperature treatment,but uniconazole would retard bolting.