The water content of cut flowers is a significant factor in their post-harvest quality. In this study, we examine the efficacy of silver nanoparticles (NS) on the longevity of cut gladiolus, with a focus on water state and distribution. We used Low-field nuclear magnetic resonance (LF-NMR) technology to identify three water fractions with different transverse relaxation times (T2) values: bound water T21 (<10 ms), intermediate immobilized water T22 (10–100 ms), and the slowest component free water T23 (>10 ms). During the opening process, T23 increased at stages 2 and 3 and then decreased, T22 decreased slowly, and T21 remained unchanged. Free water values were consistently higher than bound water and immobilized water and reached their maximum from stage 2 until stage 4, when the petals were extended and began to wilt. The vascular bundles responsible for transporting water had higher water content, as detected by proton density-weighted magnetic resonance imaging (MRI). Bound water and free water with NS pretreatments in bracts were initially lower but then two days later the signal amplitude of each water state exceeded those of the control, indicating that the treatment enhanced the water-holding capacity over time. Furthermore, NS pretreatments reduced the free water mobility of the cut flowers and inhibited stem decay. Additionally, we found that NS can enter the stem and are primarily transported upward along the xylem with water using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) technology. Overall, our findings indicate that NS pretreatment reduces free water in gladiolus cut flowers, enhancing their water retention and prolonging their vase life.

中文翻译：

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纳米银预处理可降低自由水流动性，从而延长唐菖蒲切花采后的寿命


切花的含水量是其采后质量的重要因素。在这项研究中，我们研究了银纳米颗粒 (NS) 对切割唐菖蒲的寿命的功效，重点是水的状态和分布。我们使用低场核磁共振 (LF-NMR) 技术来识别具有不同横向弛豫时间 (T2) 值的三种水组分：结合水 T21 (<10 ms)、中间固定水 T22 (10–100 ms) 和最慢的无组分水 T23 (>10 ms)。开放过程中，T23在第2、3阶段先增加后下降，T22缓慢下降，T21保持不变。自由水值始终高于结合水和固定水，并从第 2 阶段到第 4 阶段达到最大值，此时花瓣伸展并开始枯萎。质子密度加权磁共振成像（MRI）检测到，负责运输水的维管束含水量较高。 NS预处理后苞片中的结合水和游离水最初较低，但两天后每种水状态的信号幅度超过对照，表明处理随着时间的推移增强了持水能力。此外，NS 预处理降低了切花的自由水流动性并抑制了茎腐烂。此外，我们使用扫描电子显微镜 (SEM) 和能量色散 X 射线光谱 (EDS) 技术发现 NS 可以进入茎，并主要随水沿着木质部向上运输。总的来说，我们的研究结果表明，NS 预处理减少了唐菖蒲切花中的游离水，增强了其保水性并延长了其瓶插寿命。