Search Results (7)

Replacement control technology is a sustainable strategy for the control of invasive weeds. Two consecutive years of field experiments were conducted in Xichang city to assess the ecological and economical possibility of replacement control of Eupatorium adenophorum (Spreng.) King & H.Rob. with maize. Four treatment groups were planted with maize at different densities after cutting E. adenophorum. Two reference groups were set by not treating and only cutting the aerial parts of E. adenophorum. All maize replacements in the “after tillage” treatments provided control effects of up to 100% and significantly reduced water and fertilizer use by E. adenophorum. Maize replacement provided a substantial economic benefit of up to 20,273.50 and 23,633.22 yuan/hm² in two consecutive years and increased incomes. Evaluated in terms of niche theory, the large leaves as well as high plant cover assisted in effectively occupying the available niche and reduced light interception, seed germination and growth of E. adenophorum. This study provided a scientific basis for the sustainable and eco-friendly control of weeds by ecological methods. Full article

Plant invasion has severely damaged ecosystem stability and species diversity worldwide. The cooperation between arbuscular mycorrhizal fungi (AMF) and plant roots is often affected by changes in the external environment. Exogenous phosphorus (P) addition can alter the root absorption of soil resources, thus regulating the root growth and development of exotic and native plants. However, it remains unclear how exogenous P addition regulates the root growth and development of exotic and native plants mediated by AMF, affecting the exotic plant invasion. In this experiment, the invasive plant Eupatorium adenophorum and native plant Eupatorium lindleyanum were selected and cultured under intraspecific (Intra-) competition and interspecific (Inter-) competition conditions, involving inoculation with (M⁺) and without AMF (M⁻) and three different levels of P addition including no addition (P₀), addition with 15 mg P kg⁻¹ soil (P₁₅), and addition with 25 mg P kg⁻¹ soil (P₂₅) for the two species. Root traits of the two species were analyzed to study the response of the two species’ roots to AMF inoculation and P addition. The results showed that AMF significantly promoted the root biomass, length, surface area, volume, tips, branching points, and carbon (C), nitrogen (N), and P accumulation of the two species. Under M⁺ treatment, the Inter- competition decreased the root growth and nutrient accumulation of invasive E. adenophorum but increased the root growth and nutrient accumulation of native E. lindleyanum relative to the Intra- competition. Meanwhile, the exotic and native plants responded differently to P addition, exhibiting root growth and nutrient accumulation of invasive E. adenophorum increased with P addition, whereas native E. lindleyanum reduced with P addition. Further, the root growth and nutrition accumulation of native E. lindleyanum were higher than invasive E. adenophorum under Inter- competition. In conclusion, exogenous P addition promoted the invasive plant but reduced the native plant in root growth and nutrient accumulation regulated by AMF, although the native plant outcompeted the invasive plant when the two species competed. The findings provide a critical perspective that the anthropogenic P fertilizer addition might potentially contribute to the successful invasion of exotic plants. Full article

The root-knot nematode (Meloidogyne incognita) is a plant pathogen that causes significant economic damage to important food crops. The nematicidal and insecticidal effects of the essential oil and extract of the root and stem of different species of Eupatorium have been studied in several countries. We investigated the impact of root stems and leaves of the E. adenophorum on the second-stage juveniles (J2s) of M. incognita. Nematode mortality decreased by root-stem treatment and increasing temperature and time. Nematodes (J2) were more sensitive to root-stem treatment than leaf treatment at all tested conditions. For example, the half maximal effective concentration (EC₅₀) root-stems at 35 °C was estimated as 10.3 mg/g and in the 8th week as 7.8 mg/g, while the maximal effective concentration (EC_max) in leaf treatment is 20.3 and 10.1 mg/g, respectively. The E. adenophorum 40 mg/g concentration of root stems also produced the highest height of the cucumber stem and the highest cucumber fresh weight in the greenhouse. (E)-beta-farnesene, α-pinene and D-limonene, as the main identified components in fumigant plants, increased the mortality rate of J2s in root-stems treatment. We conclude that E. adenophorum dried root stems added to the soil in greenhouses have the potential as a bio-fumigant for M. incognita management. Full article

Recently, a growing emphasis has been placed on taking advantage of invasive plants for fabricating value-added and functional materials. In the present study, an easy and efficient approach to developing durably coloristic, antioxidant and antimicrobial silk using silver nanoparticles (AgNPs) prepared with the extract of an invasive weed—Eupatorium adenophorum (EA)—which plays dual roles of bio-based reductant and stabilizer. The impact of factors including pH, concentration of EA extract (EAE) and Ag⁺ ions, temperature and time during AgNPs synthesis against the nanoparticle size and distribution, and the AgNPs concentration, were explored. The relationship between the color feature of silk and the treatment conditions was investigated through a central composite experimental analysis. Finally, the antioxidant and antimicrobial activities as well as the washing durability of the AgNPs-decorated silk were demonstrated. The results revealed that the size of AgNPs also decreases when pH ranges from 7.7 to 10.1. The zeta potential of AgNPs is −18.3 mV due to the existence of EAE on the surface of AgNPs. AgNPs generated efficiently within first 30 min, and then slowed down from 30 to 60 min. Based on the mathematical modeling study, a theoretical highest KS of 6.95 is able to be obtained using the processing condition of AgNPs/EAE conc. 2.32 g/L; pH 2.65, temperature 68.6 and time 42.6 min. The silk decorated with AgNPs/EAE killed over 95% of E. coli and S. aureus within 24 h. The superb antimicrobial activity of the AgNPs-treated silk is contributed by the AgNPs that enable the microbial cell membrane damage and segmentation. After 30 times repeated washing, the antimicrobial activity of the treated silk still remained over 85% against both strains. In all, the functionalization of silk established in this work not only reduces the ecological destructions and economic losses induced by EAE, but also permits the obtaining of sustainably developed value-added, safe and functional textiles. Full article

Phytotoxic chemicals produced by alien invasive plants exert inhibitory effects on native species to facilitate their invasiveness. The allelopathic process of invaders has been hypothesized as the “Novel Weapon Hypothesis”. However, this hypothesis has been controversial for decades due to lack of molecular evidence, and the underlying mechanism of allelopathy still remains ambiguous. Herein, we explore the allelopathic mechanisms of Eupatorium adenophorum, a world-widely spread noxious weed, by the methods of laboratory bioassay and metabolomics analyses in the recipient plant, Arabidopsis thaliana. The bioassay revealed significant phytotoxicity of E. adenophorum extracts. A total of 234 metabolites in A. thaliana were detected by Gas Chromatographic−Mass Spectrometric analysis. There were 48, 99 and 94 impacted metabolites in A. thaliana treated by 50, 25 and 12.5% aqueous extracts compared to control. When mapping all the impacted metabolites to the biological pathways in the KEGG (Kyoto Encyclopedia of Genes and Genomes) database, we found mineral absorption, ABC transporters, amino acid biosynthesis, metabolic pathways and biosynthesis of plant secondary metabolites were mainly impacted. Synthesized with partial least-squares discriminate analysis (PLS-DA) results of metabolic profiles in A. thaliana, we found that citrate cycle was suppressed, metabolism of amino acids was disordered and phosphate absorption was inhibited. Subsequent investigation demonstrated that the phosphorus content in A. thaliana tissues exposed in allelopathic extracts was much lower, indicating inhibition of phosphate uptake. Our study revealed by metabolomics approaches that E. adenophorum is an allelopathic species. Full article

Eupatorium adenophorum has caused tremendous ecological and economic losses in China since the 1940s. Although a great deal of money has been expended on the prevention and control of the weed, the situation is still deteriorating. To identify its crucial environmental constraints, an ecological niche factor analysis was employed. The distribution of the weed was predicted by the maximum entropy model. The results indicate that the temperature in winter is more influential than that in other quarters of a year, and the maximum temperature in March restricts the spread of E. adenophorum most. Currently, the weed is mainly distributed in four provinces of southwest China. From the present to the 2080s, the center of L3, which has a potential distribution probability of 0.7 to 1.0, will move 53 km to the southwest. Accordingly, the area of L3 will expand by 16.04%. To prevent its further expansion, we suggest differentiating the prevention and control measures according to the potential distribution levels predicted. Meanwhile, the integration of various means of removal and comprehensive utilization of E. adenophorum is highly encouraged. Additionally, precautions should be taken in regions that have not yet, or have been only slightly, invaded by the E. adenophorum. Full article

Eupatorium adenophorum is widely distributed throughout the world’s tropical and temperate regions. It has become a harmful weed of crops and natural environments. Its leaves contain bioactive compounds such as chlorogenic acid and may be used as feed additives. In this study, chlorogenic acid was extracted and separated from leaves of E. adenophorum. Three chlorogenic acid products were prepared with different purities of 6.11%, 22.17%, and 96.03%. Phytochemical analysis demonstrated that the main toxins of sesquiterpenes were almost completely removed in sample preparation procedure. The three products were evaluated for safety via in vitro and in vivo toxicological studies. All the products exhibited no cytotoxic effects at a dose of 400 μg/mL in an in vitro cell viability assay. When administered in vivo at a single dose up to 1.5 g/kg bw, all three products caused no signs or symptoms of toxicity in mice. These results encourage further exploration of extracts from E. adenophorum in feed additive application. Full article