Effects of silicon dioxide, zinc oxide and titanium dioxide nanoparticles on Meloidogyne incognita, Alternaria dauci and Rhizoctonia solani disease complex of carrot.

Foliar spray of silicon dioxide (SiO2 NPs), zinc oxide (ZnO NPs) and titanium dioxide (TiO2 NPs) nanoparticles were used for the management of Meloidogyne incognita, Alternaria dauci and Rhizoctonia solani disease complex of carrot. Foliar spray of SiO2 NPs/ZnO NPs or TiO2 NPs increased plant growth attributes, chlorophyll and carotenoid of carrot. Foliar spray of 0.10 mg ml-1 SiO2 NPs caused the highest increase in plant growth, chlorophyll and carotenoid content of leaves followed by spray of 0.10 mg ml-1 ZnO NPs, 0.05 mg ml-1 SiO2 NPs, 0.05 mg ml-1 ZnO NPs, 0.10 mg ml-1 TiO2 NPs and 0.05 mg ml-1 TiO2 NPs. Use of SiO2 NPs caused a higher reduction in root galling, nematode multiplication and disease indices followed by ZnO NPs and TiO2 NPs. Two principal components analysis showed a total of 97.84% overall data variance in plants inoculated with single pathogen and 97.20% in plants inoculated with two or more pathogens. Therefore, foliar spray of SiO2 NPs appears interesting for the management of disease complex of carrot.

Ahamad L ，Siddiqui ZA 《-》

Use of manganese oxide nanoparticle (MnO(2) NPs) and Pseudomonas putida for the management of wilt disease complex of carrot.

Siddiqui ZA ，Khan MR ，Aziz S ，Aqib ... -  《-》

Screening of biosynthesized zinc oxide nanoparticles for their effect on Daucus carota pathogen and molecular docking.

Herein, we investigate the phytogenic synthesis of zinc oxide nanoparticles (ZnO-NPs) by using aqueous extract of seed coat of almond as a novel resource which can acts as a stabilizing and reducing agents. Successful biosynthesis of ZnO-NPs was observed by Ultraviolet-visible spectroscopy (UV-vis) showing peak at ~272 nm. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques confirm the circular shape with an average size of ~20 nm. Applications of ZnO-NPs were observed on carrot (Daucus carota) plant infected with pathogenic fungus Rhizoctonia solani. Spray with 50 ppm and 100 ppm ZnO-NPs caused significant increase in plant growth attributes and photosynthetic pigments of carrot plants. It has been reported that the synthesized ZnO-NPs demonstrated an inhibitory activity against plant pathogenic fungus R. solani and reduces disease in carrot plants. Scanning electron microscopy and confocal microscopy indicated adverse effect of ZnO-NPs on pathogens. Antifungal efficiency of ZnO-NPs was further explained with help of molecular docking analysis. Conformation with highest negative binding energy was used to predict binding site of receptor with NPs to know mechanistic approach. ZnO-NPs are likely to interact with the pathogens by mechanical enfolding which may be one of the major toxicity actions against R. solani by ZnO-NPs. RESEARCH HIGHLIGHTS: ZnO nanoparticles were synthesized using waste material from the coat of almond seeds. Images from SEM, TEM, and related techniques like EDS and SAED revealed the irregularity of the ZnO NPs as well as their atom composition. FTIR and XRD analyses confirmed the formation and the presence of crystalline ZnO NPs in nature. Biogenic ZnONPs were found to be effective against the plant pathogenic fungus R. solani. A spray of 50 ppm and 100 ppm ZnO-NPs significantly increased carrot plant growth characteristics and photosynthetic pigments.

Khan AU ，Khan M ，Malik N ，Parveen A ，Sharma P ，Min K ，Gupta M ，Alam M ... -  《-》

Biosynthesis of ZnO and TiO(2) nanoparticles using Ipomoea carnea leaf extract and its effect on black carrot (Daucus carota L.) cv. Pusa Asita.

Upadhyay DD ，Goyal AK ，Maji S ，Dwivedi A ，Pandey G ... -  《-》

Role of MgO nanoparticles in the suppression of Meloidogyne incognita, infecting cowpea and improvement in plant growth and physiology.

Root-knot disease, caused by Meloidogyne spp., alters histology as well as physiology of the roots thus influencing metabolism of vegetative and reproductive parts leading to huge losses in crop productivity. The experimental plant, Vigna unguiculata L. (cowpea of Fabaceae family) var. Gomti is an economically important pulse crop plant. An experiment was conducted to evaluate the effects of different concentrations (0, 25, 50 or 100 ppm) and various modes of applications (root dip, soil drench or foliar spray) of MgO nanoparticles on cowpea infected with M. incognita. The MgO nanoparticles were synthesized chemically and characterized by transmission and scanning electron microscopy (TEM, SEM), UV-Vis spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The scanning electron microscopy images of second stage juveniles of M. incognita treated with MgO nanoparticles (50 and 100 ppm) exhibited indentations, roughness and distortions in the cuticular surface, in comparison to the control untreated juveniles. MgO nanoparticles, in varying concentrations (50, 100 and 200 ppm), were dispensed into the plants by root dip, soil drench and foliar spray methods and their efficacy was assessed in terms of morphological characteristics, yield parameters and biochemical attributes of M. incognita infected plants. In planta trials revealed that 100 ppm dose of MgO nanoparticles, as root dip application, demonstrated reduced nematode fecundity, decreased number and smaller size of galls; enhanced plant growth, increased chlorophyll, carotenoid, seed protein, and root and shoot nitrogen contents. From these findings it could be inferred that MgO nanoparticles played twin roles, first as a nematicidal agent and the other as growth promotion inducer.

Tauseef A ，Hisamuddin ，Khalilullah A ，Uddin I ... -  《-》