Mosa Walid F A, Mackled Marwa I, Abdelsalam Nader R, Behiry Said I, Al-Askar Abdulaziz A, Basile Adriana, Abdelkhalek Ahmed, Elsharkawy Mohsen M, Salem Mohamed Z M
Department of Plant Production (Horticulture-Pomology), Faculty of Agriculture, Alexandria University, Alexandria, Egypt.
Department of Stored Product Pests, Plant Protection Institute, Agriculture Research Center, Alexandria, Egypt.
Front Plant Sci. 2022 May 23;13:898846. doi: 10.3389/fpls.2022.898846. eCollection 2022.
Ten-year-old lemon ( L. cv. Eureka) was used during the 2019 and 2020 seasons to investigate the effect of AgNPs at control, 5, 7.5, and 10 mg/L as a foliar application on vegetative growth, yield, and fruit quality. The selected trees were subjected to agricultural practices applied in the field during the study. The results indicated that the foliar application of AgNPs positively improved the shoot length, total chlorophyll, flower, and fruit set percentage, fruit yield, physical and chemical characteristics of fruits, and leaf mineral composition from macro and micronutrients compared to control in both seasons. The foliar application of AgNPs at 10 mg/L showed the highest mean values followed by 7.5 and 5 mg/L, respectively, for the previous characteristics. The treated leaves and fruit peels were hydrodistillated to extract the essential oils (EOs), and GC-MS analysis of leaf EOs. The analysis of leaves EOs showed the presence of neral, geranial, neryl acetate, and limonene as the main abundant bioactive compounds. While in peel the main compounds were neral, geranial, neryl acetate, D-limonene, geraniol acetate, linalool, and citronellal. Toxin effect of both EOs from leaves and peels were evaluated on the rice weevils () and the results indicated a higher effect of lemon peel EOs than leaves based on mortality percentage and the values of LC and LC mg/L. wood samples loaded with the produced lemon EOs were evaluated for their antifungal activity against the molecularly identified fungus, (acc # OL410542). The reduction in mycelial growth was increased gradually with the applied treatments. The most potent activity was found in lemon leaf EOs, while peel EOs showed the lowest reduction values. The mycelial growth reduction percentages reached 72.96 and 52.59%, by 0.1% leaf and peel EOs, respectively, compared with control.
在2019年和2020年生长季，选用10年生的尤力克柠檬（L. cv. Eureka），研究以5、7.5和10 mg/L的浓度进行叶面喷施纳米银颗粒对其营养生长、产量和果实品质的影响。在研究期间，对选定的植株进行田间常规农事操作。结果表明，与两个生长季的对照相比，叶面喷施纳米银颗粒对嫩梢长度、总叶绿素含量、花和坐果率、果实产量、果实理化特性以及叶片中大量和微量矿质元素组成均有积极改善作用。对于上述特性，10 mg/L纳米银颗粒叶面喷施处理的各项均值最高，其次分别是7.5 mg/L和5 mg/L处理。对处理后的叶片和果皮进行水蒸馏提取精油（EOs），并对叶片精油进行气相色谱-质谱（GC-MS）分析。叶片精油分析表明，橙花醛、香叶醛、乙酸橙花酯和柠檬烯是主要的丰富生物活性化合物。而果皮中的主要化合物为橙花醛、香叶醛、乙酸橙花酯、D-柠檬烯、乙酸香叶酯、芳樟醇和香茅醛。评估了叶片和果皮精油对米象（）的毒素作用，结果表明，基于死亡率以及致死浓度（LC）值，柠檬果皮精油的作用效果高于叶片精油。对负载所制备柠檬精油的木材样本进行了抗分子鉴定真菌（acc # OL410542）的活性评估。随着处理的进行，菌丝生长的减少量逐渐增加。最强的活性见于柠檬叶精油，而果皮精油的减少值最低。与对照相比，0.1%的叶精油和果皮精油处理的菌丝生长减少率分别达到72.96%和52.59%。
