Stem bending during vase time is a major problem in many cultivars of cut gerbera flowers. In this study, we focused on the involvement of postharvest bacteria and evaluated the efficacy of nano-silver (NS) in reducing bacterial proliferation and stem bending in cut gerbera ‘Real’ flowers in vitro and in vivo. Four species of dominant bacteria, Pseudomonas sp., Acinetobacter junii, Bacillus stearothermophilus, and Myroides sp., were isolated from the stem ends of cut gerberas. Exogenous addition of 3–5 log₁₀ colony forming units (CFU) mL⁻¹ of each bacterial species resulted in a sharp reduction in vase life, relative fresh weight, and water uptake of cut gerbera flowers. However, Pseudomonas sp. had little impact on their vase life and ornamental quality at concentrations of 3–4 log₁₀ CFU mL⁻¹. In vitro assessments showed that the minimum inhibitory concentrations (MICs) of NS for both A. junii and Myroides sp. were 2.5 mg L⁻¹, and NS MICs for B. stearothermophilus and Pseudomonas sp. were 5 and 7.5 mg L⁻¹, respectively. Additionally, compared with the control, pretreatment with 5 and 10 mg L⁻¹ NS for 24 h nearly doubled the vase life of cut gerberas, maintained their relative fresh weight, and improved water uptake. Furthermore, scanning electron microscopy revealed that the NS pretreatment reduced bacterial colonization on the stem ends. Overall, our findings indicate that all four genera of dominant bacterial species isolated from the stem ends of cut gerberas are involved in stem bending, and NS pretreatment effectively alleviated bacteria-induced xylem blockage and improved water uptake, thereby reducing the incidence of stem bending and extending the vase life of cut gerberas.

在许多非洲菊切花品种中，花瓶期茎弯曲是一个主要问题。在这项研究中，我们集中于收获后细菌的参与，并评估了纳米银（NS）在体外和体内在减少非洲菊切花“ Real”花中细菌繁殖和茎弯曲中的功效。从非洲菊切花的茎端分离出四种优势细菌，即假单胞菌属，junine不动杆菌属，嗜热脂肪芽孢杆菌和Myroides属。外源添加3–5 log ₁₀菌落形成单位（CFU）mL ^-1每种细菌种类的混合导致花瓶寿命，相对新鲜重量和切花的非洲菊切花的急剧减少。但是，假单胞菌属。在3–4 log ₁₀ CFU mL ^-1的浓度下，对花瓶寿命和观赏品质的影响很小。体外评估表明，NS对for虫和Myroides sp。的最低抑菌浓度（MIC）。分别为2.5 mg L ^-1和B. stearothermophilus和Pseudomonas sp的NS MIC 。分别为5和7.5 mg L ^-1。另外，与对照相比，用5和10 mg L ^-1进行预处理NS 24小时几乎使切成的非洲菊的花瓶寿命延长一倍，保持其相对新鲜的重量，并改善了吸水率。此外，扫描电子显微镜显示NS预处理减少了茎端细菌定植。总体而言，我们的发现表明，从切成的非洲菊的茎末端分离出的所有四个主要细菌种都参与茎弯曲，而NS预处理有效地减轻了细菌引起的木质部阻塞并改善了水分吸收，从而降低了茎弯曲和延长非洲菊切花的花瓶寿命。