Amity Institute of Microbial Technology, Amity University, Noida, 201303, India.
Department of Botany, Mahatma Gandhi Central University, Motihari, Bihar, 845801, India.
Curr Microbiol. 2022 Jul 7;79(8):244. doi: 10.1007/s00284-022-02927-0.
Black leaf spot of Brassica species is caused by a foliar pathogen Alternaria brassicicola (A. brassicicola), the noxious killer of mustard, cabbage, and cauliflower crops. The current investigation involved the synthesis of copper oxide nanoparticles (CuO NPs) from potential strain of Trichoderma harzianum (T. harzianum). Characterization of CuO NPs was performed by UV-vis, FTIR, XRD, SEM-EDX, and HR-TEM studies. UV-visible spectra showed an absorption peak at 275 nm. FTIR study revealed the presence of N-H bonds which could be due to the presence of enzymes and secondary metabolites released in the filtrate of T. harzianum. SEM and HR-TEM revealed the cube shape CuO NPs formed and average particle size was in the range of 31-45 nm. Poisoned food technique was used to check the antifungal efficacy of CuO NPs against A. brassicicola at various concentrations (0.025, 0.050, 0.1, and 0.15 mg/mL). In vitro assays carried on potato dextrose agar showed maximum antifungal activity at 0.15 mg/mL. The control sample have cylindrical and oblong shape conidia, while transverse septation was 2-4 in untreated population. The lower concentrations of CuO NPs (0.025 and 0.050 mg/mL) caused malformed spherical shape conidia with excessive septation, while its higher concentrations (0.1 and 0.15 mg/mL) leads to viability loss in fungal culture. Results indicated that a higher concentration of CuO NPs serve as an effective biocidal concentration for the control of phytopathogens.
十字花科黑叶斑病由叶病原菌交链格孢菌（A. brassicicola）引起，是芥菜、白菜和花椰菜作物的有害杀手。本研究涉及从哈茨木霉（T. harzianum）的潜在菌株中合成氧化铜纳米颗粒（CuO NPs）。通过 UV-vis、FTIR、XRD、SEM-EDX 和 HR-TEM 研究对 CuO NPs 进行了表征。紫外可见光谱在 275nm 处显示出吸收峰。FTIR 研究表明存在 N-H 键，这可能是由于哈茨木霉滤液中存在酶和次生代谢物。SEM 和 HR-TEM 显示出形成的立方体形 CuO NPs，平均粒径在 31-45nm 范围内。采用中毒食物技术在不同浓度（0.025、0.050、0.1 和 0.15mg/mL）下检查 CuO NPs 对 A. brassicicola 的抗真菌功效。在马铃薯葡萄糖琼脂上进行的体外试验表明，在 0.15mg/mL 时具有最大的抗真菌活性。对照样品具有圆柱形和长形的分生孢子，而未经处理的群体中的横向分隔为 2-4。较低浓度的 CuO NPs（0.025 和 0.050mg/mL）导致分生孢子畸形为球形，有过多的分隔，而较高浓度（0.1 和 0.15mg/mL）会导致真菌培养物的活力丧失。结果表明，较高浓度的 CuO NPs 可作为控制植物病原菌的有效杀菌浓度。
