ABSTRACT

Mongolian oak (Quercus mongolica) is an important timber species in northeast China, but overdeveloped lateral branches during the seedling stage often result in poor plant architecture and reduce the growth potential. Strigolactones (SLs) were proposed to play an important role in plant architecture by inhibiting the growth of lateral branches; however, there is no knowledge on the strigolactone effects in Mongolian oak. In this study, 0.3, 3, 10, and 30 mg/L of GR24 (analogue of SLs) and 1 mg/L Thidiazuron (TDZ) were applied to Mongolian oak seedlings by the lanolin method. All GR24 treatments significantly reduced the number and biomass of lateral branches; in addition, the length increment of lateral branches was decreased by 3, 10 and 30 mg/L GR24. In addition, the auxin content in lateral branches was significantly increased by the 10 mg/L GR24 treatment, which might be one of the main reasons for the inhibition of lateral branch growth. Increased sucrose content in apex, combined with a decrease of sucrose content in lateral branches, further demonstrated the important role of GR24 in inhibiting lateral branch growth.

摘要

蒙古栎（Quercus mongolica）)是我国东北地区重要的用材树种，但苗期侧枝过度发育，常导致株型较差，生长潜力降低。独脚金内酯 (SLs) 被提议通过抑制侧枝的生长在植物结构中发挥重要作用；然而，没有关于蒙古橡木独脚金内酯效应的知识。在这项研究中，通过羊毛脂方法将 0.3、3、10 和 30 毫克/升的 GR24（SL 的类似物）和 1 毫克/升的噻菌灵 (TDZ) 应用于蒙古橡树幼苗。所有GR24处理显着降低侧枝的数量和生物量；此外，侧枝的长度增量分别减少了 3、10 和 30 mg/L GR24。此外，10 mg/L GR24处理显着增加侧枝中的生长素含量，这可能是抑制侧枝生长的主要原因之一。顶端蔗糖含量的增加，加上侧枝中蔗糖含量的减少，进一步证明了GR24在抑制侧枝生长中的重要作用。