Effective biosafe management strategies are used to decrease world crop damage produced by plant-parasitic nematodes. This study evaluated the efficiency of hydroxyapatite nanoparticles (n-HAP) and mycorrhizal fungi to control the Meloidogyne incognita infecting tomato plants. Application of n-HAP significantly increased the juveniles’ mortality (195.67%) and egg hatching inhibition percentage (80.71%) compared to the untreated control, in vitro. Mycorrhizal and/or n-HAP treatments increased the plant growth parameters (root and shoot length, dry weight, and leaf area) and reduced the negative consequence of nematode infection. This may be due to indirect mechanisms through increasing plant nutrient uptake efficiency and increasing the internal plant resistance against nematode infection. In dual-treated plants, phosphorus, nitrogen, and calcium content recorded the highest value in the nematode-infected plants. Whereas the dual inoculation significantly increased mineral contents in tomato plants compared with control, this may induce the strength of the cell wall of the epidermal layer and cortex and consequently increase the plant resistance against nematode infection. Our results revealed that the application of the plant resistance-stimulants enhanced the plant growth parameters and internal nutrient content and reduced the nematode’s criteria. Consequently, the internal plant resistance against nematode infection was induced.

With diversity of hosts range, most identified nematode species still lack the crucial connection between morphological and molecular make-up, which is important for precisely classifying the specimens. The present study provides the complete description of Rhabdias africanus in the new host record, Sclerophrys regularis. Fifty toad specimens were collected, and a high prevalence of R. africanus infection (74%) was observed. Morphology and ultrastructure were observed using light and scanning electron microscopes. Morphological characteristics, including peculiarities of the head, the shape and position of the lips, and the number of labial papillae, were described. The length of the body, the esophageal length, the distance from an anterior end to the nerve ring, and the tail length were reduced in the studied samples relative to previously described specimens. Furthermore, some variable matrices that have not previously been described, e.g., ovarian part widening, the nerve ring and its location, and eggs with different stages of larvae, were included in the present study. Genus and species identification was confirmed by comparing partial 12S (619 bp) and ITS (878 bp) gene sequences to those of Rhabdias species deposited in GenBank. The studied species showed a 99.34% resemblance to R. africanus from South Africa. We assume our findings will aid in the molecular identification of adult and larval stages of this genus in amphibians. We strongly recommend further studies on the environmental factors that promote Rhabdias infection and transmission.

Root-knot nematodes are globally considered one of the most common phytonematodes infecting sunflower crops. In this context, current study, treatments were designed to enhancing the effect of biological control against Meloidogyne incognita by Trichoderma harzianum and Bacillus subtilis alone or in combination with antioxidant; ascorbic and salicylic acids. All treatments significantly suppressed root-knot nematode compared to control. Generally, the results indicated that the treatments of mixtures of antioxidants + bioagents showed a better response in suppression of root-knot nematode than the bioagents alone, as mixture of T. harzianum + B. subtilis gave the highest reduction in nematode population (72.3% and 80.0%).While the best synergistic effect was noticed by combination between T. harzianum and salicylic acid (74.9% and 84.9%) during the growing seasons 2018 and 2019,respectively.This positively reflected on the plant health through induction of defense related components (phenolic content and oxidative enzymes).

Molecular diagnosis represents one of the important trends in the confirmation of morphological identification to the root-knot nematodes which one of the most global pathogens. In this context, current study aimed to describe Meloidogyne javanica occurring in cucumber plants in Assiut governorate (Upper Egypt) using the random amplified polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) assay. Four mitochondrial and specific-specific sequences characterized amplified regions (SCAR) primers were used. The results showed that the SCAR primers, Fjav/Rjav and Far/Rar were efficiently amplified with 670 bp and 517 bp, respectively. On the contrary, the mitochondrial primers did not show any results. In conclusion, the present study recommended the SCAR primers as effective identified primers for the species of Meloidogyne javanica.