We investigated the leaf-associated fungal communities of Cenchrus setaceus across a host condition gradient (high- vs. low-condition plants) and environmental zones (coast vs. hill; trade-wind exposure) on Tenerife (TF) and La Palma (LP). We hypothesized that community assembly reflects both host-driven deterministic filtering and abiotic promotion of richness in favourable environments via two mechanisms: (i) high-condition plants promote stable, guild-structured communities; (ii) humid, topographically buffered zones enhance fungal richness, especially for endophytes and saprotrophs. Nanopore sequencing and functional guild annotation revealed island- and zone-specific fungal assemblages. In TF, low-condition plants were associated with genera linked to stressed or exposed conditions whereas high-condition plants, especially in humid northern hills, supported more recurrent yeast-like and niche-associated taxa. In LP, high-condition plants in eastern hill zones were associated with distinct taxa, while drier western coastal low-condition plants were enriched in stress-related fungi. Fungal genera richness (Hill0) was consistently higher in low-condition plants (TF: 146 vs. 95; LP: 94 vs. 76; p < 0.05), while Shannon diversity diverged: greater in high-condition plants on LP (3.29 vs. 2.98), but lower on TF (3.10 vs. 3.28; p < 0.05). Community structure was shaped primarily by host condition in TF (PERMANOVA R² = 8.6

Rumex lunaria is a translocated native species in Lanzarote, Canary Islands, behaving as an invasive plant that threatens conservation efforts in Timanfaya National Park and Los Volcanes Natural Park. This study explores new biocontrol techniques using two fungal strains, Alternaria alternata (strain 739) and Fusarium sp. strain 960, a member of the Fusarium incarnatum-equiseti species complex. The fungi were isolated from wild R. lunaria plants from Lanzarote and inoculated under controlled and natural conditions, in greenhouse and in two field zones of Lanzarote. In the greenhouse assays, plants inoculated via foliar spray with the Alternaria strain 739 showed specific symptoms with both a higher number of necrotic lesions and a higher percentage of affected leaves compared to control up to two weeks of trial. The application of Fusarium strain 960 to the roots led to a significant increase in abscised leaves up to 18 weeks of assessments. In the field assays, Alternaria strain 739 was applied in the summer by spraying on the R. lunaria leaves, gradually affecting the plants although no significant differences were observed in any zone. Fusarium strain 960 was applied in the autumn to the roots hindering leaves production. The patterns in both zones were similar, but faster effects were observed in Tremesana than in Mazo zone. In both field trials, pelargonic acid at 2.5

Biological control was here intended to reduce the healthy leaves volume and reproductive capabilities of the invasive plant Cenchrus setaceus using pelargonic acid (AP) and local fungal strains Fusarium and Nigrospora. The effects on the volume of healthy leaves, fungal colonization patterns, and symptoms on the foliage and reproductive organs were evaluated under greenhouse and field trials. Pelargonic acid reduced healthy leaves volume, creating a 2–3 month “opportunity window” for the fungal agents to act. AP appeared to enhance Nigrospora colonization, suggesting its utility as a pre-treatment to weaken plant defences. In the field, Fusarium-Nigrospora-pelargonic acid combined treatment (FNAP) significantly decreased healthy leaves, likely limiting resource acquisition and biomass production. Fungal colonization revealed organ-specific preferences (Fusarium: ligules and fascicles; Nigrospora: culms and leaves), thus indicating complementary niches. Both fungi were isolated seven months post-inoculation, highlighting their potential for long-term colonization. Yet, plants with even severely reduced leaf health (0–25

Cenchrus setaceus is an alien invasive species with significant ecological impact on both natural ecosystems and agricultural areas across the Canary Islands. In this study, we evaluated the allelopathic effects of foliar lixiviates from two endemic species, Artemisia thuscula and Plocama pendula, on Cenchrus setaceus and a group of crop species to assess (i) germination inhibition of the invasive species and (ii) selectivity towards non-target crops. A preliminary trial tested undiluted and diluted forms (1%, 10%) of concentrated lixiviates prepared at a 1:3 (w:v) leaf-to-water ratio, using C. setaceus and Lactuca sativa under growth chamber conditions. In the validation trial, lixiviates prepared at a 1:6 (w:v) ratio were applied directly to C. setaceus and seven crops (Zea mays, Allium cepa, Hordeum vulgare, L. sativa, Solanum lycopersicum, Brassica oleracea, and Raphanus sativus) under both growth chamber and greenhouse conditions. Germination indices were calculated across assays, and plumule and radicle lengths were measured in growth chamber assays. In both trials, C. setaceus germination was inhibited by up to 60% by both ratios of lixiviates (Dunn p < 0.05), with reduced speed and seedling growth (plumule: −37.5%; radicle: −85%). Crop sensitivity varied: A. cepa and H. vulgare showed no significant inhibition; B. oleracea and R. sativus were affected by P. pendula (germination reduced 2.5–2.7×); and Z. mays, L. sativa, and S. lycopersicum exhibited delayed germination and reduced seedling growth under both treatments. These results support the selective use of native plant lixiviates for integrated management of Cenchrus setaceus in sensitive agroecosystems.

Rumex lunaria is a translocated native species with invasive character in the island of Lanzarote (Canary Islands), threatening the fragile landscape of Timanfaya National Park and Los Volcanes Natural Park and altering the natural process of primary succession. This study explores the potential of Fusarium-derived compounds, particularly fusaric acid, to weaken Rumex lunaria populations. The effects of three different Fusarium strains culture filtrates (F. languescens, F. annulatum and F. acuminatum) were assessed, under greenhouse conditions, using leaf photosynthetic rate (assimilation of CO2 and intracellular CO2), transpiration rate, stomatal conductance, membrane permeability, chlorophyl a and b content and plant biomass. All three culture filtrates induced symptoms like chlorosis, wilting and burned or scorched leaves, a low biomass trend and a higher percentage of Rumex lunaria affected leaves. Plants treated with only mineral-based nutrient medium (Czapek) exhibited similar outcomes compared to treatments, in all measured variables. The mineral salts in this medium are likely responsible for inducing physiological stress in Rumex lunaria plants. Yet, in the field trials, only the culture filtrate strain 701 (Fusarium languescens) significantly increased the number of affected leaves and, in the greenhouse, showed a higher number of affected leaves than the other two culture filtrates and control with nutrient medium. This approach demonstrates the potential use of a fusaric acid-enriched medium to debilitate plants with invasive behaviour, particularly those already struggling to cope with harsh environments. By specifically targeting Rumex lunaria, this method could contribute to future control strategies aimed at eradicating populations from protected parks.

To mimic real-life scenarios in controlling Botrytis cinerea in tomato seedlings, we explored curative and preventive treatment strategies using crude extract from the fungal endophyte Sporormiella isomera. Curative and preventive strategies consisted of (i) seed-bath spores contamination followed by spray-treatment and (ii) seed-bath treatment followed by spray-contamination, respectively. The extract of S. isomera was bioassay-guided fractionated and sporminarin A was identified using comparative analysis of spectrometry and spectroscopy data. The efficacy of this compound and extract against pathogen was assessed in vitro (

Essential oils (EOs) from the leaves of Origanum vulgare subsp. virens (Hoffmanns. & Link) Bonnier & Layens, representing three chemotypes—thymol-rich, carvacrol-rich, and a mixed thymol–carvacrol type—were chemically characterized and comparatively assessed for their antifungal, insecticidal, and enzyme-inhibitory activities. This integrated approach provides a comparative assessment of all three chemotypes across multiple biological models, including phytopathogenic fungi, insect bioassays, and key enzyme targets. All EOs displayed antifungal activity for the tested phytopathogenic fungi (Alternaria alternata, Botrytis cinerea, and Fusarium oxysporum) at concentrations above 0.5 mg/mL, with the thymol-rich chemotype showing the highest activity. The minimum inhibition concentration for Oidium farinosum conidial growth was determined and found to be similar for thymol and carvacrol chemotypes and lower for the terpene mixture. Insect control activity was evaluated by an antifeeding assay, where carvacrol and especially thymol chemotypes can be classified as feeding deterrents. EOs and standards revealed a weak toxicity against Ceratitis capitata, with less than 20% mortality at a concentration of 50 mg/mL, and both chemotypes were found to be ineffective in preventing egg deposition. The acetylcholinesterase (AChE) inhibition assay revealed that carvacrol had the greatest inhibitory effect on AChE, followed by EOs, and, finally, thymol. Regarding the α- and β-glucosidase (α- and β-GLU) inhibitory assays, thymol had the strongest inhibitory effect on α-GLU, while plant β-GLU was not inhibited by the standards or OEs.

The endophytic fungus Sporormiella isomera strain HTF58 shows potential as a biological control agent against the tomato pathogen Botrytis cinerea. The antagonistic capacity of HTF58 against B. cinerea was evaluated through in vitro and in vivo tripartite bioassays. Establishing sufficient endophyte biomass before pathogen introduction resulted in the strongest antagonistic effect, significantly reducing symptoms and improving seedling growth. However, in vivo trials indicated that simultaneous inoculation of HTF58 and B. cinerea did not confer effective protection but did promote young plants roots growth (fresh weight: HTF58 = 22 + 10.4 g vs. negative control = 7.6 + 6.7 g; dry weight: HTF58 = 5 + 2.45 g vs. negative control = 1.8 + 1.79 g, p<0.05). Colony morphology and expansion of the endophytic S. isomera were influenced by the type of carbon and nitrogen nutrient sources provided. Organic nitrogen sources like D-alanine promoted regular lobular growth (36% increase compared to the minimal synthetic medium, p<0.05) and enhanced pigment production. S. isomera HTF58 exhibits plant growth-promoting traits, with pre-inoculation being a key factor for successful pathogen suppression.

Considering the detrimental impacts of the current pesticides on the biotic components of the biosphere, the development of novel pesticides is vital. Plant-derived biopesticides have emerged as popular alternatives to create a safer and more sustainable agriculture model. This study aims to validate the previous bioguided fractionation of endemic Canary Islands sage, Salvia canariensis, as a potential source of botanical pesticides using a cultivation process. Accordingly, the bioassay-guided fractionation of the ethanolic extract of the leaves of cultivated S. canariensis on the phytopathogenic fungal mycelia of Botrytis cinerea, Fusarium oxysporum, and Alternaria alternata yielded six known terpenoids. Their abietane diterpenoid-type (1-5) and sesquiterpenoid (6) structures were established based on spectroscopic and spectrometric analysis. This strategy identified one abietane diterpenoid, salviol (5), as a potential candidate for the future development of biofungicides with similar potency towards the assayed phytopathogenic fungi to commercial fungicides. Salviol worked in a concentration-dependent manner. Overall, this study reinforces the potential of abietane-type diterpenoids as promising agrochemical lead compounds against infectious diseases caused by phytopathogenic fungi and validates the cultivation of S. canariensis as a potential source of plant-derived biopesticides.

Background: Biofungicides arise as a promising alternative to the indiscriminate use of harmful synthetic fungicides in crop management.Results: The present study reports the bio-guided fractionation of an endemic plant from the Canary Islands, Salvia canariensis against the phytopathogens, Alternaria alternata, Botrytis cinerea, and Fusarium oxysporum. This procedure allowed identifying a series of diterpenoids with an abietane skeleton (1-5), which exhibited remarkable activity against the phytopathogenic fungi assayed. Their structures were established by means of spectroscopic and spectrometric methods, as well as comparison with reported data. Compounds 2 (carnosic acid), 4 (11-acetoxy carnosic acid) and 5 (11,12-diacetoxy carnosic acid) showed significant mycelium growth inhibition (%GI > 50 at 0.1 mg/mL concentration) on all the assayed fungi, and with a potency also higher than the positive control, Fosbel-Plus, a fungicide commonly used in agriculture. A preliminary structure-activity relationship is also discussed.Conclusions: These findings underline the aromatic abietane diterpenoids as promising eco-friendly alternatives to conventional fungicides to use in integrated pest management. (c) 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Abstract The continuous search for natural product-based biopesticides from fungi isolated from untapped sources is an effective tool. In this study, we studied a pre-selected fungal endophyte, isolate Aa22, from the medicinal plant Artemisia absinthium, along with the antifungal, insect antifeedant and nematicidal compounds present in the extract. The endophyte Aa22 was identified as Stemphylium solani by molecular analysis. The antifungal activity was tested by broth microdilution against Fusarium solani, F. oxysporum, F. moniliforme and Botrytis cinerea, the insect antifeedant by choice bioassays against Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi and the in vitro mortality against the root-knot nematode Meloiydogyne javanica. The structures of bioactive compounds were determined on the basis of 1D and 2D NMR spectroscopy and mass spectrometry. The ethyl acetate extract obtained from the solid rice fermentation showed mycelial growth inhibition of fungal pathogens (EC50 0.08–0.31 mg/mL), was antifeedant to M. persicae (99%) and nematicidal (68% mortality). A bioguided fractionation led to the isolation of the new compound stempholone A (1), and the known stempholone B (2) and stemphol (3). These compounds exhibited antifeedant (EC50 0.50 mg/mL), antifungal (EC50 0.02–0.43 mg/L) and nematicidal (MLD 0.5 mg/mL) activities. The extract activities can be explained by 3 (antifungal), 1–3 (antifeedant) and 1 (nematicidal). Phytotoxicity tests on Lolium perenne and Lactuca sativa showed that the extract and 1 increased L. sativa root growth (121–130%) and 1 reduced L. perenne growth (48–49%). These results highlight the potential of the endophytic fungi Aa22 as biotechnological source of natural product-based biopesticides.

Rumex lunaria is an endemic shrub of the Canary Islands, which is colonizing the Timanfaya National Park (TNP) in Lanzarote. Whether the arrival of R. lunaria to Lanzarote has been natural or by human intervention is still a matter of debate. To address this question, 100 specimens of R. lunaria were collected from the seven main Canary Islands, and genetic analysis of four chloroplast DNA loci were performed, covering a total length of 4809 nucleotide positions. Multiple alignments revealed 49 nucleotide substitutions, which define 30 different haplotypes. Island-specific haplotypes were found in Tenerife, La Gomera, La Palma and Gran Canaria, with the greatest diversity found in the first island. Interestingly, the unique haplotype detected in El Hierro is shared with almost all plants from Lanzarote (95%), including all individuals sampled in the TNP. The most frequent haplotype present in Gran Canaria was detected in only one sample from Lanzarote (5%). These results were corroborated by a robust phylogenetic analysis, which supports the hypothesis of a common origin of R. lunaria populations from El Hierro and the vast majority of those from Lanzarote. In addition, this study rules out the genetic singularity of the R. lunaria specimens that are colonizing the TNP.

Botanical biopesticides have emerged as sustainable and eco-friendly alternatives to synthetic pesticides, whose indiscriminate use leads to several drawbacks to human and environmental health. To the best of our knowledge, there have been no reports on M. pubescens’ bioactivity on phytopathogens affecting crops as a potential fungicide or antifeedant. This has encouraged us to investigate the potential of the roots of this plant as a source of biopesticides. The present study reports on the evaluation of the roots extract from Magonia pubescens A. St.-Hill., a species from the Cerrado (Brazilian savannah), on the phytopathogenic fungi Botrytis cinerea, Fusarium oxysporum, and Alternaria alternata. In addition, its insect antifeedant effect was assayed against Chrysodeixis chalcites. Thus, an in vitro test-assay was used to determine the fungicide potential (percentage growth inhibition, % GI) of the ethanolic extract of this plant species, whereas a leaf-disk bioassay on the 5th instar larvae of C. chalcites was performed to evaluate its insecticidal potential. The ethanolic extract was further fractionated by liquid–liquid partition using solvents of increasing polarity. The hexane/dichloromethane fraction exhibited a moderated potency and was similar to the ethanolic extract on the three assayed fungi (around % GI 30 at 1 mg/mL), whereas the n-butanol fraction showed a slight improvement of the fungicide effect against B. cinerea (% GI 39.18 at 1 mg/mL). Moreover, the ethanolic extract exhibited a strong antifeedant activity, with a refusal rate (FR) higher than 90% in both choice and non-choice assays against C. chalcites, while the ethyl acetate and n-butanol fractions behaved as appetite suppressors. These results highlight M. pubescens as a promising source of biopesticides and deserve further investigations to optimize extraction procedures.

Roads have the potential to alter local environmental conditions, such as the availability of water and nutrients, and rapidly create suitable habitats for the establishment of both native and non-native plant species, transforming the ecosystems. This is a challenge in Timanfaya National Park and Los Volcanes Natural Park on Lanzarote Island, protected areas that have experienced primary succession after recent volcanic eruptions. In arid ecosystems, changes in abiotic conditions along roadsides might facilitate colonization and plant growth. We analyzed the effect of roads and road type on plant species composition and richness at a spatiotemporal scale. Vascular plant species were systematically recorded at three distances from the road edge on both sides, across fourteen zones in the wet and dry seasons, for three years. Results showed that there were slight differences on species composition depending on the distance to the road edge, as well as on the zones. Species richness was also determined by the interaction of the position, zones, and season, being higher at the road edge. Furthermore, zones with higher traffic intensity showed a higher presence of both native and non-native species. This study highlights the importance of the awareness about the road impacts on species composition by enhancing the colonization capacity of species while facilitating the entry of invasive ones. Good management practices regarding infrastructures in natural protected areas are crucial for the conservation of their unique flora, landscapes, and natural succession processes.

Nicotiana glauca it is naturally distributed throughout South America. It was introduced in North America, Europe, Africa, Asia and Oceania and arrived to the Canary Islands as an ornamental plant, where has been invading altered soils. Endophytic fungi are known to produce active compounds that provide protection to their host against diseases and attack of herbivores, these microorganisms being an interesting source of novel molecules. So far, the endophytic fungal communities of Nicotiana have not been studied in the Canary Islands. The goal of this study is to evaluate the diversity of the fungal endophytes community associated with Nicotiana glauca. A total of 36 fungal species were isolated from roots, stems and leaves of plants collected in three locations from Tenerife Island - San Miguel de Abona, Fasnia and Puerto de la Cruz. The highest species richness values were found in leaves and stems (Margalef index = 3.33 and 3.36, respectively) versus roots (Margalef index = 2.52). Simpson's index complements the results of the Margalef index, indicating a fungal community with a high dominance value in roots (D = 0.65) due to the presence of multiple Fusarium species. Fungal community in Fasnia had the highest value of species richness (Margalef index = 3.69 versus 2.17 and 2.27 for San Miguel de Abona and Puerto de la Cruz, respectively). Results indicate fungal specificity to organ and location with 13 genera isolated from a single location and organ, among which rare species like Collariella and Gelasinospora. In this study was detected and isolated for the first time in Canary Islands the fungal species Collariella hilkhuijsenii which is of importance for the ecology of this genus scarcely known. Special attention should be offered to the presence of Fusarium, which possibly relates to the alkaloid production ability of both, the plant and the fungal strains.

Phytopathogens are responsible for great losses in agriculture. In particular, Fusarium, Alternaria and Botrytis are fungal diseases that affect crops worldwide. In the search for eco-friendly solutions to pest control, plants and their chemo-biodiversity are promising sources of biopesticides for integrated pest management. The aim of the present study is to report the evaluation of sixteen plant species from the Canary Islands Archipelago against the phytopathogenic fungi Botrytis cinerea, Fusarium oxysporum, and Alternaria alternata. The plants were selected on the basis of their traditional uses in medicine and/or pest control, as well as on scientific studies reporting their uses in crop protection. Their growth inhibition (% I), in an in vitro test-assay on mycelium, was used to identify six ethanolic plant extracts displaying activity (% I > 30% at 1 mg/mL) against at least one of the assayed fungi. The most effective plant extracts were further fractionated by liquid–liquid partition, using solvents of increasing polarity. This procedure led to an improvement of the bioactivity against the phytopathogens, even affecting the hexane fraction from S. canariensis and achieving an 83.93% of growth inhibition at 0.5 mg/mL on B. cinerea. These findings identified five plant-derived extracts as potential candidates for the future development of new biofungicides, which could be applied in integrated pest management.

Tecia solanivora is a quarantine organism regarded as one of the insect pests causing major economic losses during potato cultivation and storage in Central America. The potatoes trade between countries, the interest in introducing new potato varieties, the great adaptability of the insect to different agro-ecological conditions, and the globalization world are serious risks in other potato growing countries. This pest was first recorded in Europe in the Canary Islands, Spain, in 1999, later in Galicia (2015) and then in Asturias (2016). Unfortunately, there are no effective chemical treatments for field control, and their integrated management has variable efficacy. Therefore, the implementation of a postharvest treatment to eradicate the insect, at any stage, during storage and marketing of potato becomes essential to achieve a product free of the insect that prevents its dissemination while maintaining the quality during its commercialization. This article presents the development of a new postharvest treatment of potatoes to eliminate all developmental stages of the Guatemalan moth by the application of a control atmosphere enriched in carbon dioxide. Infested potatoes were exposed to different control atmospheres combination (10, 20, 30, 40, or 50% CO2, 20% O2, and rest of N2). These treatments were applied for 4, 7, and 10 days at 18 ± 2 °C. The 10 days duration treatment (30 ± 2% CO2, 20 ± 2% O2 and 50 ± 2% N2) killed the insect in the semi and commercial trials performed without affecting potatoes quality and postharvest life, giving the possibility of its consideration as a quarantine postharvest treatment against T. solanivora.

"Fountain grass, Cenchrus setaceus (Forssk.) Chiov. (syn. Pennisetum setaceum) is an invasive plantwith high impact on insular environments such as the Canary Islands. Although there are no mentions on C.setaceus phytopathogens, plant communities with symptoms of withering, yellowing and decay have been foundin Canary Islands. Our project aims to find autochthonous potential biological control agents for C. setaceus.Herein, we present a workflow in which we tested fast and cost-effective methods to screen a high number offungal strains, aiming features like fast colonizers as well as competitive saprophytes and facultative pathogenswith ability to cause infection. Affected plants were collected from the islands of Gran Canaria, Tenerife, LaGomera, La Palma and Lanzarote and 243 fungal strains belonging to 38 genera were isolated. First screening wasperformed on adult plants with pooled multiple species strains – spores suspensions of 10 random strains per pool,each strain representing a genus or a morphotype (n = 83). No symptoms of disease were observed. Most isolatedgenera in this study were Alternaria and Fusarium, known as cosmopolite phytopathogens. Next screeningmethods were focused accordingly. Two in vitro single-strain screening methods were employed by usingmycelium-inoculated sectioned and entire leaves, to observe the ability of tissue colonization. First screening onsectioned leaves was performed with high amount of inoculum, to increase the chances of colonization and todetermine the ability of fungi to use the plant material as substrate. The method was not effective in significantlyreducing the number of candidates as most strains had abundant growth. To detect differences in fungal strainsacting as facultative pathogens or phytopathogens, the 2nd single-strain screening was performed onphysiologically-stressed (pelargonic acid, a desiccant molecule to induce turgor loss) and not pre-treated leavesusing less inoculum. Six strains were selected and subsequently evaluated in the last in vivo screening in thepresence and absence of the desiccant. Finally, we detected strain 967 Fusarium clavum as able to colonize andreproduce at the crown of the young plants. In view of our experimental process, we propose a workflow for thecost-effective search for potential BCAs in similar situations."

In biological control one of the most common approaches is selecting microorganisms with antagonistic traits. Yet, indirect mechanisms of plant growth promotion may give advantages in biotic stress by allowing plants to overcome the colonization of the pathogen. Rapid methods of combined antagonistic and plant growth promotion traits are scarce. Here we propose a method for screening potentially bioactive fungal endophytes in a tripartite interaction “endophytes - Alternaria - tomato seedlings”. Endophytes are known to interact with pathogens chemically inhibiting their growth or development by means of specific biologically active metabolites, mycoparasitism, or by competition for nutrients, or indirectly by inducing resistance mechanisms in the host. The proposed method here could substitute the conventional assays of antagonism in dual culture (i.e. fungus – fungus), having introduced from the beginning the central biological actor, the plant. Results indicate that the order of arrival of each actor determines if seedling colonization or enhancement of seedling growth occur as the antagonistic interaction between endophyte and pathogen may precede the latter beneficial interactions.