Solanum Elaeagnifolium Research Articles

Learning to handle flowers increases pollen collection for bees but does not affect pollination success for plants

Abstract Cooperation and conflict are common in plant–pollinator interactions. Flowering plants often entice pollinators to visit by offering floral food rewards, thereby facilitating pollination. However, pollinators such as bees can learn to improve their collection of floral rewards (such as pollen), changing how they interact with the flower’s reproductive organs, which together could reduce pollination success. Consequently, complex flowers that slow pollinator learning might benefit the plant. Yet how pollinator learning and flower complexity interact to affect pollination success is unknown. We therefore asked how differences in complexity of 4 flower types (Phacelia campanularia, Exacum affine, Solanum elaeagnifolium, and Erythranthe guttata) affected learning by pollen-foraging generalist bumble bees (Bombus impatiens) and how learning affected pollen collection and pollen deposition on these flowers. We found that bees generally learned how to efficiently handle more complex flower types more slowly. Bees that required more visits to become efficient foragers collected less pollen, with no effect on pollen deposition. Except for the simplest flower type, learning also involved development of motor routines unique to each flower type. Experienced bees overall collected more pollen, but individual differences in motor routines did not affect pollen collection. Conversely, individual differences in motor routines affected pollen deposition, but there was no overall effect of experience. Thus, even though learning overall benefits the bee, it does not alter female (and potentially male) fitness benefits for the plant. We discuss potential reasons for these patterns and consequences for bee behavior and flower evolution.

Assessing the climatic niche changes and global invasion risk of Solanum elaeagnifolium in relation to human activities

As an invasive plant, Solanum elaeagnifolium has posed a serious threat to agriculture and natural ecosystems worldwide. In order to better manage and limit its spread, we established niche models by combining distribution information and climate data from the native and invasive ranges of S. elaeagnifolium to analyze its niche changes during its colonization. Additionally, we evaluated its global invasion risk. Our results showed that the distribution of S. elaeagnifolium is affected by temperature, precipitation, altitude, and human activities. Solanum elaeagnifolium exhibits different degrees of niche conservatism and niche shift in different invasion ranges.During the global invasion of S. elaeagnifolium, both the niche shift and conservatism were observed, however, niche shift was particularly significant due to the presence of unoccupied niches (niche unfilling). Solanum elaeagnifolium generally occupied a relatively stable niche. However, a notable expansion was observed primarily in Europe and China. In Australia and Africa, its niche largely remains a subset of its native niche. Compared to the niche observed in its native range, its realized niche in China and Europe has shifted toward lower temperature and higher precipitation levels. Conversely, in Africa, the niche has shifted toward lower precipitation levels, while in Australia, it has shifted toward higher temperature. Our model predicted that S. elaeagnifolium has high invasion potential in many countries and regions. The populations of S. elaeagnifolium in China and Africa have reached the adapted stage, while the populations in Australia and Europe are currently in the stabilization stage. In addition, our research suggests that the potential distribution of S. elaeagnifolium will expand further in the future as the climate warms. All in all, our study suggests that S. elaeagnifolium has high potential to invade globally. Due to its high invasive potential, global surveillance and preventive measures are necessary to address its spread.

Bioactivity of silverleaf nightshade (Solanum elaeagnifolium Cav.) berries parts against Galleria mellonella and Erwinia carotovora and LC-MS chemical profile of its potential extract

Natural products received much attention as an environmentally beneficial solution for pest management. Therefore, the extracts of invasive silverleaf nightshade (Solanum elaeagnifolium Cav.) weeds using their berries parts (seeds, peels and mucilage) supported by bioassay-guided fractionation were tested against both the greater wax moth (Galleria mellonella) and Erwinia carotovora pv. carotovora causes of the blackleg of potatoes. The seeds and peels of S. elaeagnifolium were successively extracted by maceration using dichloromethane (DCM), ethyl acetate (EtOAc), and ethanol (EtOH), respectively. While, its mucilage was extracted using EtOAc. The successive EtOH extract of the plant seeds had promising inhibition efficacy and the best minimal inhibition concentration (MIC) of 50 µg/ml against E. Carotovora amongst other extracts (DCM and EtOAc of the plant berries parts). Depending on dose response activity, EtOH extract had G. mellonella larval mortality and pupal duration rates (LC50; 198.30 and LC95; 1294.73 µg/ml), respectively. Additionally, this EtOH extract of seeds was fractionated using preparative TLC to three characteristic bands. The insecticidal and bacterial activities of these isolated bands (SEA, SEB, and SEC) were evaluated at a dose of 100 µg/ml, causing mortality by 48.48, 62.63 and 92.93% (G. mellonella larvae) and inhibition by 15.22, 0.00 and 31.66 mm (E. carotovora), respectively. Moreover, the separated major three bands were tentatively identified using LC-ESI-MS analysis revealing the presence of two phenolic acids; chlorogenic acid (SEA) and dicaffeoyl quinic acid (SEB) in addition to one steroidal saponin (SEC) annotated as borassoside E or yamoscin. Finally, the plant seeds’ successive EtOH extract as well as its active constituents, exhibited potential broad-spectrum activity and the ability to participate in future pest management initiatives. A field study is also recommended to validate its bio-efficacy against selected pests and to develop its formulations.

Bioaccumulation and Translocation of Heavy Metals in Solanum elaeagnifolium

Heavy metal pollution is becoming an increasingly common problem. Heavy metals including Chromium, Cadmium, Mercury, Copper, and lead are hazardous environmental pollutants, especially in high anthropogenic activity areas. Heavy metals accretion in soil is a serious concern for agricultural productivity due to its negative influence on food safety, market potential, and the phytotoxicity it causes in crops. Plant ascendancy and metabolic processes affect the geological and biological re-distribution of heavy metals through air, soil, and water pollution. The typical result of heavy metals toxicity is excessive accumulation of reactive methylglyoxal and oxygen species, which lead to lipid peroxidation, enzyme inactivation, nucleic acid damage, and protein oxidation in plants. In this study, bioaccumulation and Translocation of Heavy Metals in Solanum elaeagnifolium was conducted by using standard biological techniques. Twenty-four samples of both shoot and root systems collected ‎from the study sites and Three replications of soil samples from each habitat, including topsoil (0-50 cm depth) were studied.our results showed that the quantitative concentration of heavy metals in the shoots of S. elaeagnifolium for each metal indicated a high enrichment value for (Cr), (Fe), and (Mn), on the other hand, it showed low enrichment values for (Ni) & (Pb). In addition, the concentration of heavy metals in the roots of the plant was differentiated.

Physico-Chemical Properties, Phytochemical Screening and Antioxidant Potential of Polar and Non-Polar Seed Extractions of Selected Medicinal Plants of Solanaceae

The objective of this study was to investigate the various bioactive components and assess the biological activity in the seeds of five medicinal plants (Datura innoxia Miller., Solanum elaeagnifolium Cav., Solanum nigrum L., Solanum surattense Burm., and Withania coagulans (Stocks) Dunal.) in Solanaceae family. In this regard, ash values, acid-insoluble ash and water-soluble ash values, extractive values and screening of various phytochemicals (alkaloid, carbohydrate, protein, flavonoid, tannins, saponins, and fixed oil) and quantitative estimation of carbohydrate and protein of seeds of selected plants have been calculated. The 2,2-diphenyl-1-picryl hydrazyl (DPPH) free radical scavenging assay was used to evaluate the antioxidant potential. Captivatingly, a phytochemical screening assay affirmed the presence of saponins, terpenoids, phenolic compounds, and flavonoids in the seeds of all examined plants. The highest amounts of DPPH radical-scavenging activity were found in the aqueous extract of W. coagulans (IC50 = 65.6 µg/ml). Consequently, current findings showed all selected plants of the family Solanaceae contain highly bioactive components, which could be used for the treatment of different diseases and as a potential resource for discovering new drugs.

Utility potential of the aggressive invasive Solanum elaeagnifolium Cav. (Solanaceae) as an option to control its expansion: bioactive compounds and medicinal properties

Utility potential of the aggressive invasive Solanum elaeagnifolium Cav. (Solanaceae) as an option to control its expansion: bioactive compounds and medicinal properties

The Possible Role of Bird Migrations on Introduction and Spread of Invasive Alien Plants: A Case Study, Solanum elaeagnifolium Cav.

Solanum elaeagnifolium (SOLEL), a native plant of the Americas is a highly spread invasive alien species worldwide with impacts on biodiversity and agriculture. It has a long history in Mediterranean basin and the Middle East where Türkiye is located but there was no record except one in 2006 from the eastern the Mediterranean of Türkiye of which introduction was attributed to migrating birds. Despite widespread and large populations in neighboring countries, not detecting SOLEL in Türkiye had been questionable. The aims of the study were to find out new populations of SOLEL in Türkiye and understand the reason of less population occurred in Türkiye. Two areas were selected near the country borders of Türkiye which are known as migrating bird routes. Areas were visited unregularly several times from 2020 to 2023 to find out SOLEL populations. New populations were detected in the eastern Mediterranean and Aegean Regions of Türkiye which are over 1000 km apart from each other. SOLEL populations and bird migration routes through Türkiye and countries SOLEL has already been recorded were compared. It is concluded that SOLEL might be introduced by migrating birds. It is suggested that more detailed research is needed to explain the role of migrating birds in invasive alien plants’ introductions. Furthermore, plants around wetlands which birds use in their migration routes should be observed to prevent new plant invasions.

Boosting Tomato Resilience in Tanzania: Grafting to Combat Bacterial Wilt and Abiotic Stress

The grafting technique has successfully mitigated crop losses from diseases and stress in vegetable production; however, vegetable grafting in Tanzania is very limited. Field and greenhouse experiments conducted in Tanzania’s mainland and islands compared the response of tomato determinate cv. ‘Tanya’ to production challenges when ungrafted and grafted onto five tomato rootstocks (‘Hawaii 7796’, ‘Tengeru 1997’, ‘Tengeru 2010’, ‘R3034’, and ‘Shelter’), one eggplant variety (‘EG 203’), and one wild Solanum species (Solanum elaeagnifolium). The visual symptoms of bacterial wilt varied significantly with location and season, ranging from 8 to 100%, attributed to varying bacterial wilt pressures and strains of Ralstonia solanacearum isolated (Phylotype I sequevars 17, 18, and 31). ‘EG203’ and ‘Hawaii 7796’ emerged as the most effective rootstocks, reducing wilting by 49.8 and 51.0% and improving yield by 57.2% and 27.7% on average across experiments conducted in three locations (Moshi, Pemba, and Unguja) over two seasons. Combining reduced water supply with grafting resulted in an average reduction in wilting of 76%, while also boosting yields by an average of 3.6 times in experiments conducted in Arusha over two seasons. Grafting onto ‘Hawaii 7796’ and ‘Shelter’ significantly improved ‘Tanya’ yields by 38.3% and 41.6% on average over two seasons, only under standard nutrient application rates. While certain rootstocks improved crop performance, yields across various sites and seasons were significantly hampered by pest pressure. These findings support grafting’s potential to mitigate damage from common stresses, emphasizing the need for further research to identify suitable rootstocks for optimizing returns on investments in grafted plants in Tanzania.

Morphological and molecular characterisations of Orosius albicinctus (Distant, 1918)

ABSTRACT Leafhoppers (Hemiptera: Cicadellidae) are important agricultural pests and potential vectors of several viruses and phytoplasma diseases. The Chickpea chlorotic dwarf virus (CpCDV) is reported in Tunisia and is transmitted by leafhoppers. In order to identify potential insect species transmitting the virus in Tunisia, a survey was carried out during 3 years (2019–2021) in fields of tomatoes, pepper, melon, watermelon, and chickpea in six governorates (Tunis, Nabeul, Sousse, Monastir, Mahdia, and Kairouan). Morphological and molecular barcoding studies allowed identifying the leafhopper Orosius albicinctus (Distant, 1918) (Cicadellidae: Deltocephalinae: Opsiini) on chickpeas, melon, a co-culture of watermelon and pepper, and on associated weeds (Solanum elaeagnifolium and Cynodon dactylon) in Kairouan and Mahdia. This is first record of this leafhopper species in Tunisia.

Potential subterranean interference of Solanum elaeagnifolium, commonly known as silverleaf nightshade, on durum wheat

Aim of study: Silverleaf nightshade (Solanum elaeagnifolium) has evolved as an invasive weed in Greece, affecting many farmers’ fields. The potential subterranean interference of silverleaf nightshade on durum wheat growth and yield, as well as its aqueous extracts phytotoxic activity on four winter cereals were investigated. Area of study: Northern Greece. Material and methods: The phytotoxic activity of silverleaf nightshade was determined in the laboratory using a perlite-based bioassay. The interference of silverleaf nightshade on durum wheat yield components was investigated by a 3-year field experiment. Main results: The silverleaf nightshade leaves/stems or the flowers/fruits extracts were in most cases more phytotoxic than those of roots. Durum wheat and oats were more sensitive than winter wheat and barley. In the field, the incorporated summer biomass of 14-18 plants m-2 (about 4.5-4.8 t ha-1) of silver nightshade caused 14.5, 23.1, 23.3, 15.9, 17.3 and 16.9% reduction (averaged across years) in durum wheat plant number, tiller number, total fresh weight, total dry weight, ear number and seed yield, respectively, compared with the silver nightshade-free plots (control). The corresponding reductions caused by 30-34 plants m-2 (about 8.3-8.6 t ha-1) were 28.5, 41.2, 45.9, 31.5, 27.0 and 31.2%. Research highlights: The presence of aboveground silver nightshade biomass, incorporated by tillage before seeding significantly reduced the emergence, growth and yield of durum wheat. This fact could be attributed to the allelopathic effect of the weed and demonstrates the need for its control before wheat establishment to enhance wheat productivity.

Proteolytic, milk-clotting, and stability properties of proteases from Solanum elaeagnifolium fruit

Solanum elaeagnifolium (trompillo) has been considered a new alternative source of proteolytic enzymes for cheese-making. However, properties for this proteolytic source still need to be described. This study evaluated the proteolytic (PA) and milk-clotting activity (MCA) as well the stability properties for the proteases found in S. elaeagnifolium fruit extract (FE). Proteolytic enzymes were active in a broad pH range with a maximum at pH 10.0 and 80 °C and showed high stability in a wide pH (5.0–12.0) and temperature ranges (30–75 °C). MCA increased with the temperature in a range of 30–85 °C. Proteases from S. elaeagnifolium FE presented high thermostability, retaining 40% of the activity after 15 min of incubation at 80 °C. Temperatures higher than 85 °C caused the total PA loss. Phenylmethylsulphonyl fluoride (PMSF) inhibited more than 95% of the PA, indicating that the activity is mainly related to serine proteases. In addition, a casein hydrolysis profile, by SDS-PAGE, showed that proteases degrade α, β, and κ-casein with high affinity. S. elaeagnifolium fruit contains abundant proteolytic enzymes with high catalytic properties and activity over different protein substrates. Therefore, S. elaeagnifolium fruit represents a potential source of serine proteases for use in different biotechnological processes, offering attractive properties such as high activity in a broad pH and temperature range, high thermal stability, and preference over different natural substrates.

Modeling the effect of temperature on rhizome sprouting in the invasive weed silverleaf nightshade (Solanum elaeagnifolium)

AbstractSilverleaf nightshade (Solanum elaeagnifolium Cav.), a noxious, highly invasive perennial weed, poses a significant threat to irrigated summer crops, vegetables, and orchards. This weed has the ability to reproduce both sexually through seed production and asexually via an extensive underground rhizome network, the latter playing a major role in the weed’s invasion, establishment, and persistence. Our aims were thus to assess the impact of temperature on rhizome sprouting for fragments of different lengths and to model the sprouting dynamics. The influence of temperature on the sprouting of rhizome fragments (2.5-, 5-, 7.5-, or 10-cm long) was investigated in growth chambers at eight temperatures ranging from 10 to 45 C. The highest sprouting proportions for 10-cm rhizome fragments were recorded at 30 and 35 C in complete darkness. The highest sprouting time for all fragment lengths was observed at 15 C in complete darkness. Modeling sprouting rates as a function of temperature gave the cardinal temperatures for the four different rhizome fragment lengths, with Tb (base temperature) values of 12.80, 9.34, 9.14, and 9.50 C, To (optimal temperature) values of 38.9 $$0$$ , 36.60, 35.16, and 34.86 C, and Tc (ceiling temperature) values of 39.80, 40.08, 40.50, and 40.80 C for rhizome lengths of 2.5, 5, 7.5, and 10 cm, respectively. Based on these findings, the potential for S. elaeagnifolium to spread to new areas and possible new management strategies are discussed; these offer a novel approach for informed decision making regarding the control of this weed.

Phytochemical composition, anti-microbial, anti-oxidant and anti-diabetic effects of Solanum elaeagnifolium Cav. leaves: in vitro and in silico assessments

The aim of this study was to screen the chemical components of Solanum elaeagnifolium leaves and assess their therapeutic attributes with regard to their antioxidant, antibacterial, and antidiabetic activities. The antidiabetic effects were explored to determine the α-amylase and α-glucosidase inhibitory potential of the leaf extract. To identify the active antidiabetic drugs from the extracts, the GC-MS-screened molecules were docked with diabetes-related proteins using the glide module in the Schrodinger Tool. In addition, molecular dynamics (MD) simulations were performed for 100 ns to evaluate the binding stability of the docked complex using the Desmond module. The ethyl acetate had a significant total phenolic content (TPC), with a value of 79.04 ± 0.98 mg/g GAE. The ethanol extract was tested for its minimum inhibitory concentration (MIC) for its bacteriostatic properties. It suppressed the growth of B. subtilis, E. coli, P. vulgaris, R. equi and S. epidermis at a dosage of 118.75 µg/mL. Moreover, the IC50 values of the ethanol extract were determined to be 17.78 ± 2.38 in the α-amylase and and 27.90 ± 5.02 µg/mL in α-glucosidase. The in-silico investigation revealed that cyclolaudenol achieved docking scores of −7.94 kcal/mol for α-amylase. Likewise, the α-tocopherol achieved the docking scores of −7.41 kcal/mol for glycogen phosphorylase B and −7.21 kcal/mol for phosphorylase kinase. In the MD simulations, the cyclolaudenol and α-tocopherol complexes exhibited consistently stable affinities with diabetic proteins throughout the trajectory. Based on these findings, we conclude that this plant could be a good source for the development of novel antioxidant, antibacterial, and antidiabetic agents. Communicated by Ramaswamy H. Sarma

UPLC-HR-ESI-MS ANALYSIS AND ANTIPROLIFERATIVE AND ANTI-DIABESITY SCREENING OF FLOWERS, ROOTS, AND AERIAL PARTS OF SOLANUM ELAEAGNIFOLIUM CAV.

Objective: Solanum elaeagnifolium Cav. is an invasive summer-growing wild perennial herb but is traditionally used to treat some health conditions, including toothache and constipation. This study aimed to identify the chemical composition of various parts of this herb (flowers, roots, and aerial parts) and explore its biological properties. Methods: Ultra-Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS) was used for the first time for the root to analyze the hydro-alcoholic extract besides flowers and aerial parts of S. elaeagnifolium. Sulforhodamine B (SRB) assay was used to assess the antiproliferative effects of the same extracts on the colorectal cancer cell lines (CACO2, SW620, HT29, and HCT116). The aqueous extracts of the plant’s three parts were evaluated in vitro for their anti-diabesity properties. Results: For the first time, other compounds in three plant parts were identified using UPLC-MS: hyperoside and apigenin (flavonoids), in flowers and roots, naringin (flavonoid) in the roots, and apigenin (flavonoid) in aerial parts, diosgenin (steroids sapogenin) solamargine, and solasodine (alkaloids) in the three parts. In addition to the previously identified compounds; chlorogenic acid and kaempferol were in the aerial part, and flowers; and luteolin (flavonoids) were in the aerial parts. Pharmacologically, the aqueous extracts of flowers and roots proved anti-diabesity activity, and no anti-proliferative effect was detected for their hydro-alcoholic extracts. Neither anti-obesity nor anti-proliferative activities were detected in the aerial part extracts. Conclusion: Further in vivo and in vitro investigations are required for the different parts of S. elaeagnifolium to explore more biological activities and evaluate the plant’s toxicity.

Allelopathy of invasive weed Solanum elaeagnifolium Cav.: an investigation in germination, growth and soil properties

Allelopathy of invasive weed Solanum elaeagnifolium Cav.: an investigation in germination, growth and soil properties

Biology of Invasive Plants 5. Solanum elaeagnifolium Cav.

The family Solanaceae lists about 1,400 species worldwide, of which 143 are considered weeds (Sheppard et al. 2006). The genus Solanum is the most numerous of the family Solanaceae. Solanum elaeagnifolium Cav. belongs to the clade Leptostemonum, commonly known as the “spiny solanum” clade. Solanum elaeagnifolium is native to northern Mexico and the American Southwest. A revision for the S. elaeagnifolium clade and analytic phytokeys are provided by Knapp et al. (2017). The silvery color of its leaves and their resemblance to the leaves of the olive tree (Elaeagnus) were the reasons for naming the species elaeagnifolium (Heap and Carter 1999). Nowadays, it is commonly known as silverleaf nightshade (Boyd et al. 1984). According to Krigas et al. (2021), in northern Greece S. elaeagnifolium is also called “Lernaean Hydra,” due to its intense regrowth after herbicide treatment. Solanum elaeagnifolium is known in South Africa as silverleaf bitter apple or Satansbos (Satan’s bush), indicating how harmful it is to the country (Wilson et al. 2013). In America and other parts of the world, it has received various names over the years, such as white horsenettle, bullnettle, tomatillo, meloncillo, and trompillo (Davis et al. 1945; Kwong et al. 2006). In Algeria, farmers call it echouka, which means thorn, because of the multiple spines on the stem (Adjim and Kazi Tani 2018). In South Korea, it received the name Eun-bit-kka-ma-jung, which is a combination of its silvery coloration and a common plant in the country (Hong et al. 2014).

Evaluation of three sets of advanced backcrosses of eggplant with wild relatives from different gene pools under low N fertilization conditions.

The development of new cultivars with improved nitrogen use efficiency (NUE) is key for implementing sustainable agriculture practices. Crop wild relatives (CWRs) provide valuable genetic resources for breeding programs aimed at achieving this goal. In this study, three eggplant (Solanum melongena) accessions together with their advanced backcrosses (ABs; BC3 to BC5 generations) were evaluated for 22 morpho-agronomic, physiological, and NUE traits under low nitrogen (LN) fertilization conditions. The ABs were developed with introgressions from the wild relatives Solanum insanum, Solanum dasyphyllum, and Solanum elaeagnifolium. The AB population comprised a total of 25, 59, and 59 genotypes, respectively, with overall donor wild relative genome coverage percentages of 58.8%, 46.3%, and 99.2%. The three S. melongena recurrent parents were also evaluated under control (normal) N fertilization. Reduction of N fertilization in the parents resulted in decreased chlorophyll content-related traits, aerial biomass, stem diameter, and yield and increased NUE, nitrogen uptake efficiency (NUpE), and nitrogen utilization efficiency (NUtE). However, the decrease in yield was moderate, ranging between 62.6% and 72.6%. A high phenotypic variation was observed within each of the three sets of ABs under LN conditions, with some individuals displaying improved transgressive characteristics over the recurrent parents. Using the single primer enrichment technology 5k probes platform for high-throughput genotyping, we observed a variable but high degree of recurrent parent genome recovery in the ABs attributable to the lines recombination, allowing the successful identification of 16 quantitative trait loci (QTL). Different allelic effects were observed for the introgressed QTL alleles. Several candidate genes were identified in the QTL regions associated with plant growth, yield, fruit size, and NUE-related parameters. Our results show that eggplant materials with introgressions from CWRs can result in a dramatic impact in eggplant breeding for a more sustainable agriculture.

Predicting the realised host-range of Leptinotarsa texana with open-field experiments

ABSTRACT The leaf beetle Leptinotarsa texana is a potential biological control agent for silverleaf nightshade Solanum elaeagnifolium in Australia. However, previous research has shown that L. texana can develop on the non-target crop eggplant Solanum melongena in quarantine cage experiments. We used open-field experiments in the agent's native range of Texas, USA, to clarify the realised host-range of L. texana in relation to S. melongena. We conducted five replicated field experiments to investigate: (1) the extent that L. texana would show a preference for oviposition when presented with both S. elaeagnifolium and S. melongena in an open-field context, and (2) the extent that larvae would move from defoliated S. elaeagnifolium onto either nearby S. melongena plants, or bypass S. melongena in search of S. elaeagnifolium. We found, in the open-field experiments, that adult females prefer S. elaeagnifolium over S. melongena plants for settling and oviposition and, in fact, observed no oviposition on S. melongena in any experiment. However, the low levels of oviposition observed in the S. elaeagnifolium experimental plants (the control) was insufficient to conclusively demonstrate that S. melongena is not within the realised host-range of L. texana adults. We also found evidence that L. texana larvae can cause spill-over damage to S. melongena in situations where co-occurring S. elaeagnifolium is defoliated. Finally, we demonstrate the use of an argument map to visually represent the contributions of multiple, sometimes conflicting, field and laboratory experiments to biological control agent risk analysis.

The Invasion of Alien Populations of Solanum elaeagnifolium in Two Mediterranean Habitats Modifies the Soil Communities in Different Ways.

We aimed to explore how the invasion of the alien plant Solanum elaeagnifolium affects soil microbial and nematode communities in Mediterranean pines (Pinus brutia) and maquis (Quercus coccifera). In each habitat, we studied soil communities from the undisturbed core of both formations and from their disturbed peripheral areas that were either invaded or not by S. elaeagnifolium. Most studied variables were affected by habitat type, while the effect of S. elaeagnifolium was different in each habitat. Compared to maquis, the soil in pines had higher silt content and lower sand content and higher water content and organic content, supporting a much larger microbial biomass (PLFA) and an abundance of microbivorous nematodes. The invasion of S. elaeagnifolium in pines had a negative effect on organic content and microbial biomass, which was reflected in most bacterivorous and fungivorous nematode genera. Herbivores were not affected. In contrast, in maquis, organic content and microbial biomass responded positively to invasion, raising the few genera of enrichment opportunists and the Enrichment Index. Most microbivores were not affected, while herbivores, mostly Paratylenchus, increased. The plants colonizing the peripheral areas in maquis probably offered a qualitative food source to microbes and root herbivores, which in pines was not sufficient to affect the much larger microbial biomass.

Solanum elaeagnifolium and S. rostratum as potential hosts of the tomato brown rugose fruit virus.

Invasive weeds cause significant crop yield and economic losses in agriculture. The highest indirect impact may be attributed to the role of invasive weeds as virus reservoirs within commercial growing areas. The new tobamovirus tomato brown rugose fruit virus (ToBRFV), first identified in the Middle East, overcame the Tm-22 resistance allele of cultivated tomato varieties and caused severe damage to crops. In this study, we determined the role of invasive weed species as potential hosts of ToBRFV and a mild strain of pepino mosaic virus (PepMV-IL). Of newly tested weed species, only the invasive species Solanum elaeagnifolium and S. rostratum, sap inoculated with ToBRFV, were susceptible to ToBRFV infection. S. rostratum was also susceptible to PepMV-IL infection. No phenotype was observed on ToBRFV-infected S. elaeagnifolium grown in the wild or following ToBRFV sap inoculation. S. rostratum plants inoculated with ToBRFV contained a high ToBRFV titer compared to ToBRFV-infected S. elaeagnifolium plants. Mixed infection with ToBRFV and PepMV-IL of S. rostratum plants, as well as S. nigrum plants (a known host of ToBRFV and PepMV), displayed synergism between the two viruses, manifested by increasing PepMV-IL levels. Additionally, when inoculated with either ToBRFV or PepMV-IL, disease symptoms were apparent in S. rostratum plants and the symptoms were exacerbated upon mixed infections with both viruses. In a bioassay, ToBRFV-inoculated S. elaeagnifolium, S. rostratum and S. nigrum plants infected tomato plants harboring the Tm-22 resistant allele with ToBRFV. The distribution and abundance of these Solanaceae species increase the risks of virus transmission between species.