Plant-parasitic nematodes (PPNs) are found in citrus plantations throughout the world, but they are considered to be the most problematic pest in Morocco. Citrus fruit quality and yield have been adversely affected by PPNs. Due to data unavailability of nematodes associated with citrus, a detailed survey was conducted in the main citrus-growing regions of Morocco during 2020–2021 to assess the occurrence, distribution, and diversity of PPNs associated with rhizospheres of citrus trees. In addition, some soil properties have also been assessed for their impact on soil properties. Plant-parasitic nematode diversity was calculated using two ecological indexes, the Shannon diversity index (H′) and the Evenness index (E). The collected soil and root samples were analyzed, and eleven genera and ten species of plant-parasitic nematodes were identified. The results show that the most predominant PPN species were Tylenchulus semipenetrans (88%), Helicotylenchus spp. (75%), Pratylenchus spp. (47%), Tylenchus spp. (51%), and Xiphinema spp. (31%). The results showed that PPN distributions were correlated with soil physicochemical properties such as soil texture, pH levels, and mineral content. Based on the obtained result, it was concluded that besides the direct effects of the host plant, physicochemical factors of the soil could greatly affect PPN communities in citrus growing orchards.

In Morocco, extensive use, traditional practices, and climate change have seriously impacted the productivity of aromatic and medicinal plants (AMP). To mitigate these adverse effects, this study aims at evaluating the potential of the arbuscular mycorrhizal fungi (AMF), namely Rhizophagusirregularis and Funneliformis mosseae, in improving biomass, essential oils (EOs), and biomolecule production in Thymus satureioides, T. pallidus, and Lavandula dentata. Compared to non-inoculated-AMP, AMF induced significant increases in biomass production by 37.1, 52.4, and 43.6%, and in EOs yield by 21, 74, and 88% in T. satureioides, T. pallidus, and L. dentata, respectively. The EOs of inoculated-AMP exhibited increased proportions of major compounds such as thymol (23.7%), carvacrol (23.36%), and borneol (18.7%) in T. satureioides; α-terpinene (32.6%), thymol (28.79%), and δ-terpinene (8.1%) in T. pallidus; and camphor (58.44%), isoborneol (8.8%), and fenchol (4.1%) in L. dentata. Moreover, AMF significantly improved the anti-germinative and antifungal activities of the EOs. Indeed, IC₅₀ values decreased by 1.8, 16.95, and 2.2 times against Blumerai graminis, Zymoseptoria tritici, and Fusarium culmorum, respectively, compared to non-inoculated-AMP. This study highlights the performance of the symbiosis between AMF and AMPs in terms of high quality of EOs production while respecting the environment. The associations F. mosseae-Thymus and R. irregularis-Lavandula are the most efficient.

To ensure the preservation and sustainable use of Lavandula dentata, we have examined the impact of different growth conditions on cultivated and wild L. dentata essential oils (EOs) composition and biological activities, along with the biomass of root and soil microorganisms. Gas chromatography analysis revealed 21 and 23 components in the EO of the wild and culti-vated plants, accounting for over 98% of the total composition in both cases. The major com-pounds of wild EO were borneol (49.47%), eucalyptol (23.01%), β-pinene (3.95%), β-eudesmol (3.79%), and myrtenol (3.61%). In contrast, the EO extracted from cultivated plants was charac-terized by a high content of borneol (32.83%), isobornyl acetate (24.45%), eucalyptol (14.71%), and α-pinene (5.83%). Unique compounds were found in wild and cultivated EO, such as lin-alool, cis-verbenol, carveol, α-selinene, and terpinyl acetate or tricyclene, d-limonene, cam-phene hydrate, and isobornyl acetate, respectively. PLFA analysis revealed a higher microbial biomass in both soil (10.393 µg/g) and the roots (68.04 µg/g) of the wild plants compared to the cultivated ones (3.91 µg/g in soil and 62.04 µg/g in roots), driven especially by gram negative bacteria in soil, and by saprotrophic fungi in the roots. The biological activities of the EOs var-ied with, the growth conditions, with the wild EO demonstrating superior antibacterial, anti-fungal, antioxidant, and nematicidal properties. Our results highlight the importance of natu-ral growth conditions in shaping the chemical composition of L. dentata EO. Nevertheless, cul-tivation practices could serve as a promising alternative to ensure the sustainable use of this species, provided they are managed under appropriate agronomic and ecological conditions

To ensure the preservation and sustainable use of Lavandula dentata L., we examined the impact of various growth conditions on the composition of essential oils extracted from the leaves of both cultivated and wild L. dentata. Additionally, we assessed the biological activities of these essential oils, along with the biomass of the root and soil microorganisms. Gas chromatography analysis revealed 21 and 23 components in the EO of the wild and cultivated plants, accounting for over 98% of the total composition in both cases. The major compounds of wild EO were borneol (49.47%), eucalyptol (23.01%), β-pinene (3.95%), β-eudesmol (3.79%), and myrtenol (3.61%). In contrast, the EO extracted from cultivated plants was characterized by a high content of borneol (32.83%), isobornyl acetate (24.45%), eucalyptol (14.71%), and α-pinene (5.83%). Unique compounds were found in wild and cultivated EO, such as linalool, cis-verbenol, carveol, α-selinene, and terpinyl acetate or tricyclene, d-limonene, camphene hydrate, and isobornyl acetate, respectively. PLFA analysis revealed a higher microbial biomass in both soil (10.393 µg/g) and the roots (68.04 µg/g) of the wild plants compared to the cultivated ones (3.91 µg/g in soil and 62.04 µg/g in roots), driven especially by Gram-negative bacteria in soil, and by saprotrophic fungi in the roots. The biological activities of the essential oils showed some variations with growth conditions, with the wild EO generally exhibiting slightly higher antibacterial, antifungal, antioxidant, and nematicidal activities in certain assays. Overall, our findings indicate that the essential oils from wild and cultivated L. dentata exhibit comparable biological value, although some differences were observed. In particular, the wild EO tended to show significantly higher biological activities in certain assays, which may be associated with its distinct chemical composition and growth environment. However, these differences were moderate and not consistently significant across all tests. Therefore, properly managed cultivation can be a dependable alternative for producing L. dentata essential oil, helping to reduce pressure on natural populations.

Plant biostimulants are increasingly recognized as natural solutions that enhance plant growth and support sustainable agriculture. However, their effects on soil microbial communities remain poorly understood. This study evaluated three biostimulants: Plantiful™ (fermented marine algae with beneficial bacteria), CelexT07™ (fermented medicinal plants with beneficial bacteria), and Phylgreen™ (seaweed extract), compared with water and conventional NPK fertilization. Rhizospheric microbial biomass, community structure, and metabolic potential were assessed using metabarcoding, phospholipid fatty acid (PLFA) profiling, and Biolog EcoPlates™ assays. Total microbial biomass did not differ significantly from the untreated control. Similarly, bacterial biomass (7.4–9.8 µg/g soil) remained stable across treatments. Saprotrophic fungal biomass was 2–4-fold lower under Phylgreen^TM and CelexT07^TM than NPK, but comparable to the control. Bacterial and fungal communities were dominated by Actinobacteriota, Pseudomonadota, Acidobacteriota, Chloroflexota, and Ascomycota, with similar richness and diversity across treatments in wheat rhizosphere soil after 9 weeks of growth. Functional analyses revealed only modest shifts, with AWCD being significantly reduced by 43.5% under Phylgreen™ (64.11) compared with NPK (113.44), while remaining comparable to the untreated control (94.74). The network analysis results were also consistent with the previous results, indicating that biostimulant treatments maintained microbial richness. Overall, these findings support the use of the tested biostimulants as sustainable crop management tools that preserve rhizosphere microbial communities.