Agricultural Research Center, Plant Pathology Research Institute, 9 Gamaa St., Giza 12619, Egypt.
Department of Agronomy, Agricultural Research Center, Londrina State University, Londrina, PR 86057-970, Brazil.
Int J Biol Macromol. 2021 Jan 31;168:242-250. doi: 10.1016/j.ijbiomac.2020.12.047. Epub 2020 Dec 9.
The main purpose of this study was to explore the ability of a novel silica/polysaccharide polymer-based formulation, namely, chitosan/silica nanocomposites (CSNs), to directly affect Botrytis cinerea in vitro and in inoculated berries, and indirectly to induce natural host resistance via enzymatic and nonenzymatic antioxidants against gray mold of table grapes. The results indicated a positive correlation in in vitro tests in terms of radial growth, spore germination and germ tube elongation, where those parameters were completely inhibited by CSN at 1%. SEM and TEM investigations showed that morphological and internal structural damage was observed in B. cinerea-hyphae/spores treated with CSN. Additionally, most of the treated spores were affected, and cellular vacuolization and cytoplasmic disorganization were observed. The results revealed that CSN reduced gray mold incidence and severity on inoculated berries directly and indirectly. In direct activity, CSN (1%) reduced mold incidence and severity by 100% compared to the control. In indirect activity, mold incidence and severity was reduced by 51% and 64%, respectively. CSN significantly increased superoxide dismutase, ascorbate peroxidase, peroxidase, total phenol and flavonoid at 48 h post-treatment by 1.2-, 1.6-, 1.3-, 1.3- and 1.6-fold, respectively, in grape-treated tissues. It could be concluded that CSN, as a promising alternative control method against gray mold of table grapes, can directly affect the pathogen and indirectly enhance the natural host resistance of the antioxidant system.
本研究的主要目的是探索一种新型的基于硅/多糖聚合物的制剂，即壳聚糖/硅纳米复合材料（CSN），在体外和接种浆果中直接影响灰葡萄孢的能力，以及通过酶和非酶抗氧化剂间接诱导天然宿主对葡萄灰霉病的抗性。结果表明，在体外测试中，CSN 在径向生长、孢子萌发和芽管伸长方面呈正相关，其中 CSN 在 1%的浓度下完全抑制了这些参数。SEM 和 TEM 研究表明，CSN 处理的灰葡萄孢菌丝/孢子观察到形态和内部结构损伤。此外，大多数处理过的孢子受到影响，出现细胞空泡化和细胞质紊乱。结果表明，CSN 直接和间接降低了接种浆果上灰霉病的发病率和严重程度。在直接活性方面，CSN（1%）与对照相比，将发病率和严重度降低了 100%。在间接活性方面，发病率和严重度分别降低了 51%和 64%。CSN 显著增加了超氧化物歧化酶、抗坏血酸过氧化物酶、过氧化物酶、总酚和类黄酮，在处理后的 48 小时内分别增加了 1.2 倍、1.6 倍、1.3 倍、1.3 倍和 1.6 倍。可以得出结论，CSN 作为一种有前途的防治葡萄灰霉病的替代方法，可以直接影响病原体，并间接增强抗氧化剂系统的天然宿主抗性。
