香菇,在中国东南部具有重要经济价值的雌雄异株红豆杉科植物,由于性器官的异步成熟和花粉活力低,对自然授粉提出了挑战。为了通过对T.grandis进行人工授粉来提高受精成功率,本研究探讨了大头草花粉离体萌发和花粉管生长的最佳条件。发现最佳的体外生长培养基含有29mM蔗糖,0.8mMH3BO3,0.72mMCaCl2和0.32mMMgSO4,补充有4μMNAA,在pH=5.6时,2μM的GA3和5μM的2,4-D。在这些条件下,在28°C下发芽6天后,我们实现了最大花粉发芽率为69.99±5.17%,花粉管长度为34.38±6.04µm。FM4-64染料和MitotrackerRed染色显示出囊泡和线粒体在发芽过程中的高度动力学,它们积聚在花粉管的尖端,并表现出双相运动模式。总数,运动速率,囊泡和线粒体的运动速度显示出最初的增加,然后逐渐减少。培养基中蔗糖的存在显着增加了囊泡和线粒体的动力学和代谢活性,与蔗糖耗尽的条件相比,这可能与更高的花粉发芽率和更快的花粉管生长有关。因此,这些发现揭示了香火花粉萌发的生理特性,为通过人工授粉提高香火果实产量提供了科学依据。
Torreya grandis, a dioecious Taxaceae species of significant economic value in southeast China, presents challenges for natural pollination due to asynchronous maturation of its sex organs and low pollen vitality. In order to enhance fertilization success through artificial pollination of T. grandis, this study investigated the optimal conditions for in vitro pollen germination and pollen tube growth of T. grandis. The optimal in vitro growth medium was found to contain 29 mM sucrose, 0.8 mM H3BO3, 0.72 mM CaCl2, and 0.32 mM MgSO4, supplemented with 4 μM NAA, 2 μM GA3, and 5 μM 2,4-D at pH=5.6. Under these conditions, we achieved a maximum pollen germination ratio of 69.99 ± 5.17 % and a pollen tube length of 34.38 ± 6.04 µm after 6 days germination at 28°C. FM4-64 dye and Mitotracker Red staining revealed highly dynamics of
vesicles and mitochondria during germination, which were accumulated at the tip of pollen tube and exhibited biphasic movement patterns. The total number, motion rate, and movement velocity of
vesicles as well as mitochondria showed an initially increase followed by a gradual decrease pattern. The presence of sucrose in the medium significantly increased the dynamics and metabolic activity of both
vesicles and mitochondria, which may relate with higher pollen germination ratio and faster pollen tube growth compared to sucrose-depleted conditions. Thus, these findings shed light on the physiological characteristics of Torreya pollen germination and provide scientific information for improving Torreya fruit yield through artificial pollination.