Background: The present study investigated the antifungal activity and mode of action of four Olea europaea leaf extracts, Thymus vulgaris essential oil (EO), and Boswellia carteri EO against Fusarium oxysporum. Methods:Fusarium oxysporum lactucae was detected with the internal transcribed spacer (ITS) region. The chemical compositions of chloroform and dichloromethane extracts of O. europaea leaves and T. vulgaris EO were analyzed using GC-MS analysis. In addition, a molecular docking analysis was used to identify the expected ligands of these extracts against eleven F. oxysporum proteins. Results: The nucleotide sequence of the F. oxysporum lactucae isolate was deposited in GenBank with Accession No. MT249304.1. The T. vulgaris EO, chloroform, dichloromethane and ethanol efficiently inhibited the growth at concentrations of 75.5 and 37.75 mg/mL, whereas ethyl acetate, and B. carteri EO did not exhibit antifungal activity. The GC-MS analysis revealed that the major and most vital compounds of the T. vulgaris EO, chloroform, and dichloromethane were thymol, carvacrol, tetratriacontane, and palmitic acid. Moreover, molecular modeling revealed the activity of these compounds against F. oxysporum. Conclusions: Chloroform, dichloromethane and ethanol, olive leaf extract, and T. vulgaris EO showed a strong effect against F. oxysporum. Consequently, this represents an appropriate natural source of biological compounds for use in healthcare. In addition, homology modeling and docking analysis are the best analyses for clarifying the mechanisms of antifungal activity.

Grafting is a safe agro-technique used to boost tolerance against biotic and abiotic stresses and increase crop yield and quality. This study was undertaken to control cucumber Fusarium wilt through grafting onto novel Cucurbit interspecific hybrids and assess their effect on nutrients, defense enzymes in cucumber, and root characteristics. Four crosses were done between two lines of each of Bottle Gourd (Lagenaria siceraria), Winter squash (Cucurbita maxima), Winter squash (C. moshata), and Wild cucumber (C. zambinus). The commercial hybrid rootstock Supper Shintosa was also considered. Results indicated that all hybrid rootstocks, except Bottle Gourd, exhibited a significant decrease in Fusarium wilt severity compared with non-grafted control. Plant height and shoot dry weight of grafted plant were higher than those of the nongrafted control with best results for grafting onto C. moshata. The macro (N, P, K, Ca, and Mg%) and micro (Fe and Zn ppm) nutrient contents in the leaf of grafted plants were more than those of the nongrafted control. The highest macro and micronutrient contents were observed due to grafting onto C. moshata followed by C. maxima. Grafting of cucumber onto resistant rootstocks exhibited a significant increase in activity of peroxidases and polyphenoloxidase enzymes. Furthermore, grafting onto all rootstocks, except C. zambinus, caused an increase in root diameter more than the nongrafted control. Grafted cucumber onto C. maxima rootstock showed the best values in terms of diameter of the root, thickness of the cortex, dimension of vascular bundle, mean diameter of the vessel, and the pith over the nongrafted control.

Wheat has a remarkable importance among cereals worldwide. Wheat stem and leaf rust constitute the main threats that destructively influence grain quality and yield production. Pursuing resistant cultivars and developing new genotypes including resistance genes is believed to be the most effective tool to overcome these challenges. This study is the first to use molecular markers to evaluate the genetic diversity of eighteen Egyptian wheat genotypes. Moreover, the molecular docking analysis was also used to assess the Cu-chitosan nanoparticle (CuChNp) treatment and its mode of action in disease control management. The tested genotypes were categorized into two main cluster groups depending on the similarity matrix, i.e the most resistant and susceptible genotypes to stem and leaf rust races. The results of SCoT primers revealed 140 polymorphic and 5 monomorphic bands with 97% polymorphism. While 121 polymorphic and 74 monomorphic bands were scored for SRAP primers (99% polymorphism). The genotypes Sakha 94, Sakha 95, Beni Sweif 4, Beni Sweif 7, Sohag 4 and Sohag 5 were resistant, while Giza 160 was highly susceptible to all stem rust races at the seedling stage. However, in the adult stage, the 18 genotypes were evaluated for stem and leaf rust-resistant in two different locations, i.e. Giza and Sids. In this investigation, for the first time, the activity of CuChNp was studied and shown to have the potential to inhibit stem and leaf rust in studied Egyptian wheat genotypes. The Spraying Cu-chitosan nanoparticles showed that the incubation and latent periods were increased in treated plants of the tested genotypes. Molecular modeling revealed their activity against the stem and leaf rust development. The SRAP and SCoT markers were highly useful tools for the classification of the tested wheat genotypes, although they displayed high similarities at the morphological stage. However, Cu-chitosan nanoparticles have a critical and effective role in stem and leaf rust disease control.