Irani Sepideh Famil, Arab Mostafa, Vahdati Kourosh, Lotfi Mahmoud, Roozban Mahmoud Reza
Department of Horticulture, Faculty of Agricultural Technology (Aburaihan), University of Tehran, Tehran, Iran.
Sci Rep. 2025 Aug 28;15(1):31664. doi: 10.1038/s41598-025-17474-4.
In cut stock (Matthiola incana L.), inflorescence bending is primarily caused by the bending moment generated by the weight of the floral structure. This phenomenon results in drooping of inflorescence onto neighboring plants, diminishing ornamental quality and increased space requirements among plants. Reduction of the bending moment increases the inflorescence's curvature radius, limits apical deviation and enables more compact plant spacing. This study investigated the individual and interactive effects of three auxins (IAA, NAA and IBA) and three cytokinins (KIN, BA and ZT), each applied three times beginning at the 10-leaf stage and repeated at 7-day intervals at the concentrations of 0, 10 and 100 ppm. Treatments were evaluated through a series of nine factorial experiments. Of the 81 auxin-cytokinin combinations tested, 15 treatments completely prevented inflorescence bending by producing upright stems. The effective treatments significantly reduced the length-to-diameter ratio (LDR) (p < 0.05), which was strongly correlated with both apical deviation (δ) and bending stress. LDR had a greater influence on δ than the stem's Young's modulus (E), suggesting that hormonal crosstalk primarily affected stem geometry rather than material stiffness. Notably, combinations of IBA with either KIN or ZT improved biomechanical stability by lowering the center of gravity, and shortening the torque arm, thereby reducing bending stress below critical levels. Treatments containing BA were associated with higher E and mechanical resistance index (MRI), indicating enhanced stem stiffness. Among the most effective combinations, IAA 10 ppm + BA 10 ppm yielded the most visually desirable inflorescences-long, straight stems with ideal floret arrangement.
在香雪球（Matthiola incana L.）中，花序弯曲主要是由花结构重量产生的弯矩引起的。这种现象导致花序垂向相邻植株，降低了观赏品质，并增加了植株间的空间需求。减小弯矩可增加花序的曲率半径，限制顶端偏差，并实现更紧凑的植株间距。本研究调查了三种生长素（IAA、NAA和IBA）和三种细胞分裂素（KIN、BA和ZT）的单独及交互作用，每种激素从10叶期开始施用3次，每隔7天重复一次，浓度分别为0、10和100 ppm。通过一系列九因素实验对处理进行评估。在测试的81种生长素 - 细胞分裂素组合中，15种处理通过产生直立茎完全防止了花序弯曲。有效的处理显著降低了长径比（LDR）（p < 0.05），长径比与顶端偏差（δ）和弯曲应力均密切相关。长径比对δ的影响大于茎的杨氏模量（E），这表明激素相互作用主要影响茎的几何形状而非材料刚度。值得注意的是，IBA与KIN或ZT的组合通过降低重心和缩短力臂提高了生物力学稳定性，从而将弯曲应力降低到临界水平以下。含有BA的处理与较高的E和机械抗性指数（MRI）相关，表明茎的刚度增强。在最有效的组合中，IAA 10 ppm + BA 10 ppm产生了视觉上最理想的花序——长而直的茎，小花排列理想。
