Green Bristlegrass Research Articles

Effects of host plants on aphid feeding behavior, fitness, and Buchnera aphidicola titer.

Aphids are sap-feeding plant pests that depend on their symbiotic relationships with the primary endosymbiont Buchnera aphidicola to adapt to impoverished diets. However, how the host plant affects the aphid primary symbiont and aphid adaptation to host plant transfer are poorly known. In this study, aphid symbiont screening and genotype identification were used to establish 2 aphid strains (Rhopalosiphum maidis [Rm] and Rhopalosiphum padi [Rp] strains) containing only Buchnera without any secondary symbionts for both wheat aphid species (R. maidis and R. padi). Aphid fitness and Buchnera titers were unstable on some of these host plants after transferring to novel host plants (G1-G5), which were influenced by host plant species and generations; however, they stabilized after prolonged feeding on the same plants for 10 generations. The electropenetrography (EPG) records showed that the allocation of aphid feeding time was significantly distinct in the 6 host plants; aphids had more intracellular punctures and spent more nonprobing time on green bristlegrass which was not conducive to its growth compared with other plants. The content of soluble sugar, soluble protein, and amino acid in the leaves of the 6 host plants were also clearly separated. The correlation coefficient analysis showed that the nutrient contents of host plants had significant correlations with aphid feeding behaviors, fitness, and Buchnera titers. In the meantime, aphid fitness, and Buchnera titers were also affected by aphid feeding behaviors. Also, Buchnera titers of aphid natural populations on 6 host plants showed a visible difference. Our study deepened our understanding of the interaction among aphids, endosymbionts, and host plants, indicating that the host plant nutrient content is a predominant factor affecting aphid adaptation to their diet, initially affecting aphid feeding behaviors, and further affecting aphid fitness and Buchnera titers, which would further contribute to exploiting new available strategies for aphid control.

Phytotoxic Effects and Potential Allelochemicals from Water Extracts of Paulownia tomentosa Flower Litter

Flowers of Paulownia spp. wither and fall on a large scale after blooming in spring and have potential allelopathic effects on surrounding plants, including crops and weeds. In this study, the phytotoxic effects of water extracts of Paulownia tomentosa flower litter (EPF) on wheat (Triticum aestivum L.), lettuce (Lactuca sativa L.), green bristlegrass (Setaria viridis L.) and purslane (Portulaca oleracea L.) were evaluated in the laboratory. The mode of action of the phytotoxicity of EPF on lettuce seedlings was studied and the secondary metabolites in EPF were analyzed by liquid chromatography high-resolution mass spectrometry (LC-HRMS). The results show that EPF significantly inhibited the seed germination and seedling growth of four target plants in a concentration-dependent manner. In addition, EPF could induce the excessive accumulation of reactive oxygen species (ROS) flowing with oxidative damage of the lipid bilayer of the biofilm, resulting in reduced cell viability and even apoptosis in lettuce. There were 66 secondary metabolites identified by LC-HRMS in P. tomentosa flowers. Among them, 10 compounds, including salicylic acid, caffeic acid, parthenolide, 7-hydroxycoumarin and abscisic acid (ABA), were all known allelochemicals. In summary, P. tomentosa flower litter displayed significant allelopathic effects, which were related to the accumulation of ROS in target plants. Phenolic acids, flavonoids as well as ABA are probably the main allelochemicals of P. tomentosa flowers.

Эффективность новых гербицидов на посевах кукурузы в условиях Западного Предкавказья

When studying the effectiveness of using promising herbicides on crops of corn hybrids in the central zone of the Krasnodar Territory, it was found that corn crops are predominantly contaminated with dicotyledonous weeds such as Theophrastus rope, upturned acorn grass, ragwort, white pigweed, self-seeded poppy, and shepherd’s purse. Cereal (monocot) weeds are represented by blue bristle grass, green bristle grass and chicken millet. Perennial weeds include by field bindweed. The most effective herbicide is Adengo in the 1–2 leaf stage, giving a yield increase of 56.1 c/ha. At the same time, corn hybrids in the mid-early group yielded 91.5 c/ha and those in the mid-ripening group 77.1 c/ha. To obtain a corn yield of 100 c/ha, it is necessary to apply the herbicide Adengo (0.5 l/ha) at the stage of 1–2 leaves in the technology of cultivation of its hybrids DKS3969, DKS3 and DKS3789

First Report of Bipolaris zeae Causing Leaf Spot on Setaria viridis in China.

Green bristlegrass (Setaria viridis) is an annual dominant herb in arid sandy grasslands with strong drought resistance to water stress (Valença et al. 2020). In August 2021, brown or dark tan spots on the leaves of S. viridis were observed on natural grassland in Qingyang city, Gansu Province, China (36.55°N, 107.32°E). Leaf disease incidence was around 13%, and the infected area of each leaf was about 20%. For isolation, 30 tissue pieces (5×5 mm) from 10 symptomatic leaf samples were surface-sterilized with 70% ethanol for 30 seconds and rinsed three times with steriled distilled water. Then these tissues were placed on the potato dextrose agar (PDA) at 25 °C, and incubated in dark from 2 to 5 days. Sixteen single-spored cultures with consistent colony characteristics were obtained by single spore isolation as described in Manamgoda et al. (2012). Colonies on PDA were irregular shapes with black color and white edge; conidia were dark brown with septate, cylindrical, straight or flexuous geniculate at the upper end, 22.7 to 69.38×9.2 to 17.6 µm (n = 50; average size 40.8×13.2 µm) under microscope (40X). The internal transcribed spacer (ITS) and glyceraldehyde-3-phosphate dehydrogenase (GPD) regions of the representative isolate 83HXGWC, 84HXGWC and 85HXGWC were amplified using the primers of ITS1/ITS4 and GPD1/GPD2 (Manamgoda et al. 2012). All the amplified gene sequences were deposited into GenBank with accession numbers ITS (OP703331, OQ978850, and OQ978851) and GPD (OQ559683, OQ992505, and OQ992506). BLAST analysis of both the two segments showed 100% identity with those reported sequences of ex-type isolate BRIP 11512 (KJ415538 and KJ415408) of B. zeae Sivan (Tan et al. 2014; Bhunjun et al. 2020), respectively. In the maximum-likelihood phylogenetic tree, 83-HXGWC, 84HXGWC and 85HXGWC strains were grouped with the reference sequences of B. zeae with a high bootstrap supporting values of 100%. Five healthy green bristlegrass (6 weeks) plants in pots were sprayed with conidial suspensions (1×106 conidia ml-1). Another five pots were sprayed with sterilized distilled water (controls). Then all pots were individually covered with transparent polyethylene bags for 5 days to maintain high relative humidity and placed in a greenhouse maintained at 18 to 25 °C. After incubation for 14 days, the typical symptoms of leaf spots developed from brown to dark brown on the plants inoculated with conidial suspension, whereas no symptoms were observed on the control plants. The measurement of pathogenicity was carried out three times. The same pathogens were consistently reisolated from inoculated leaves, and was confirmed as B. zeae based on morphological and molecular analyses, fulfilling Koch's postulates. This study provides a new record of B. zeae on green bristlegrass on natural grassland in China, which can potentially impose disease challenges to other crops. Since, B. oryzae has been known to cause disease in cereal crops (Manamgoda et al. 2014), this can be a potential alternate source of survival of this pathogen.

Sensitivity of weeds to herbicide Lumax and its effectiveness in grain maize crops

Sensitivity of weeds to Lumax herbicide under growing conditions with pre- and post-emergent application was studied. Evaluation of biological and economic efficiency of Lumax herbicide at different terms of use was given. The studies were conducted in 2020–2022 in the Primorsky Territory. The soil of the experimental plots is meadow-brown podzolized, containing 3–4% of humus in the arable horizon. The agricultural technique is based on no-tillage technology. The forecrop was soybeans. The hybrid population P 8521 was used in the field experiments. The sensitivity of 16 weed species was studied when used in pre-emergence applications and 18 when used on vegetative plants in the early stages of their development. Visual observations of plant development after treatments with Lumax herbicide were made. At soil application, the preparation inhibited the germination of lamb’s-quarters, pigweed, hemp nettle, barnyard grass, bur beggar-ticks, yellow-foxtail grass and green bristle grass, field milk thistle and yellow thistle. Sprouts of China jute, common persicaria and copper leaf were completely dead by the 7th day. Moderate sensitivity was shown by ragweed, hairy cupgrass, and dayflower. Trailing hollyhock proved to be resistant to this herbicide. When using Lumax on vegetating plants, 17 species were highly sensitive, with only hairy cupgrass being relatively sensitive. In field experiments in the grain maize crop, weed infestation averaged 531 plants/m2 with a total above ground mass of 3279 g/m2. The herbicide was applied at three times: before sprouting, in the phases of the 2-3rd and 5th-6th of corn leaves. There were advantages and disadvantages with each term of its use. At preemergence, it more actively suppressed annual grasses, while at late (the 5th-6th leaf phase) it suppressed perennial dicotyledons. Application of the herbicide in the 2nd-3rd corn leaf phase showed approximately equal effect on the weeds. Lumax effectively eliminated dayflower and annual dicotyledonous weeds. Regardless of the timing of application, it contributed to saving 29.8-36.7 co of corn grain/ha.

Glufosinate Ammonium-Loaded Halloysite Nanotubes for Slow-Release Weeding Polymer Mulch Films

Improving the performance and giving function to poly(butylene adipate-co-terephthalate) (PBAT)-based biodegradable mulch film have always been research hotspots. However, the problems of a translucent PBAT-based film, which decreases in performance over time and is easily damaged by weeds, need to be solved. In this study, 11.17 wt % of the commercial contact herbicide Glufosinate-ammonium (Glu) was loaded into the lumen of halloysite nanotubes (HNTs). The Glu-loaded HNTs (Glu@HNTs) and other treatment groups were further incorporated into the PBAT/poly(lactic acid) (PLA) composite films by melt blending and blow molding. Results demonstrated that Glu, HNTs, and Glu@HNTs dispersed uniformly in the composite films. Remarkably, while maintaining the original tensile strength of the film, the nominal strain of transverse fracture was increased by 19.6% to 51.2%, and the least water vapor transmission was reduced by 46.7% to 68.5%. Furthermore, the composite films added with Glu@HNTs can successfully kill green bristlegrass and show a good slow-release effect, which can avoid premature release of the herbicide before the weeds grow up. Overall, the combination of inorganic nanofiller-modified PBAT/PLA film and weeding has positive significance for reducing soil pollution and helping the long-term efficient use of biodegradable mulching.

Off/on switchable smart electromagnetic interference shielding aerogel

Summary Smart electromagnetic interference (EMI) shielding materials with tunable EM wave response characteristics are attractive for future EM devices. Here, we report an off/on switchable EMI shielding material that can be tuned from EM wave transmission to shielding and vice versa by mechanical compression and decompression. This smart material is prepared by filling conductive carbon nanoparticles into wood-derived lamellar carbon aerogel, showing reversible compressibility and strain-sensitive conductivity. The original aerogel has good impedance matching and low dielectric loss, allowing the EM wave to pass through. Mechanical compression enables the carbon nanoparticles to establish highly conductive pathways in the aerogel, which significantly increases the conductivity of aerogel and thus activates its EMI shielding performance. This function switch is reversible by repeatedly compressing and decompressing the aerogel. The availability of such a never-before-realized off/on switchable EMI shielding material provides an opportunity for the development of advanced smart EM devices.

Effects of liquid digestate on the valence state of vanadium in plant and soil and microbial community response

Liquid digestate containing high levels of nutrients and humic and fatty acids can affect vanadium species and their plant uptake. To elucidate the effects of liquid digestate on the valence state of vanadium in soil and plant tissue, as well as its effects on the microbial community and soil properties, we grew green bristlegrass (Setaria viridis), a native plant capable of growing in vanadium mining areas, in vanadium-contaminated soils sampled from a mining area and treated it with 5% and 10% liquid digestate for 90 d, respectively. Changes in the concentrations of pentavalent (V[V]) and tetravalent (V[IV]) vanadium in the soils and the shoots and roots of bristlegrass and the soil microbial abundance were measured. The results showed that vanadium existed mainly in the form of V(IV) in the soil but accumulated mainly in the form of V(V) in the bristlegrass. Liquid digestate markedly reduced V(V) concentrations in the soils (by up to 45%) and in the shoots and roots of green bristlegrass (by up to 98%). Liquid digestate enhanced the abundance of Bacteroidetes, which can reduce V(V) to lower valence state. Microbial reduction and phosphorus immobilization were responsible for downregulating V(V) concentrations in the plant and soil. The liquid digestate can be used to enhance in situ bioremediation of vanadium-contaminated soil in mining area.

Bioinspired preparation of regular dual‐level micropillars on polypropylene surfaces with robust hydrophobicity inspired by green bristlegrass leaves

The fine microstructure on the natural green bristlegrass leaf of Setaria viridis (L.) Beauv, which exhibits a contact angle (CA) of 155°±2° and a rolling angle (RA) of 79°±2°, is carefully observed. Based on the understanding of the underlying mechanisms for superhydrophobicity and moderate surface adhesion, an efficient replica molding strategy is proposed for mimicking the microstructures on green bristlegrass leaf surface to polypropylene (PP) surfaces. The bioinspired PP replica with dual‐level micropillars are molded by using the unitized template of steel Meshes A and B. Interestingly, the PP replica inherits both hydrophobicity and adhesion of the natural leaf. Furthermore, the PP replica can stabilize its hydrophobic state under a 980 Pa external pressure, which is attributed to the composite Cassie‐Wenzel mixed wetting state on the microstructured interface. The CA comparatively goes down and RA increases, resulting in superhydrophobic surface with moderate adhesion on the bioinspired surface. Hence, the microstructures and hydrophobicity are successfully replicated to the PP surface by only using the low cost, available and reliable steel meshes in the bioinspired replica molding process.

Analysis of Pyricularia oryzae and P. grisea from Different Hosts Based on Multilocus Phylogeny and Pathogenicity Associated with Host Preference in China

Pyricularia oryzae and P. grisea are important agents of major diseases on a wide range of gramineous hosts. Whereas P. oryzae is the most important pathogen causing outbreaks of rice blast, P. grisea is mainly a pathogen of crabgrass. In this study, 103 P. oryzae and 20 P. grisea isolates were collected from seven species of plants, and we analyzed their phylogeny, pathogenicity, and relationship with host preferences to investigate the differences among them from different hosts. Based on phylogenetic analysis of multilocus sequences, 16 isolates from crabgrass and four isolates from green bristlegrass were identified as P. grisea and another 103 isolates from crabgrass, green bristlegrass, goose grass, foxtail millet, wild millet, rice, and sedge belonged to P. oryzae. Results of pathogenicity tests by artificial inoculation demonstrated that six of 10 P. oryzae isolates from rice and three of 44 P. oryzae isolates from green bristlegrass showed cross-infectivity on green bristlegrass and rice, respectively. Taken together, our results demonstrated that isolates from green bristlegrass and crabgrass consist of both P. oryzae and P. grisea and that P. oryzae isolates showed cross-infectivity between rice and green bristlegrass, suggesting that host shifts may occur for P. oryzae and P. grisea.

Wheat egg in vitro fusion with wheat and green bristlegrass sperm.

SummaryIsolated gametes can be used to investigate fertilization mechanisms, and probe distant hybridization between different species. Pollen grains of wheat and Setaria viridis are tricellular, containing sperm cells at anthesis. Sperm from these plants were isolated by breaking open pollen grains in a osmotic solution. Wheat ovules were digested in an enzyme solution for 20 min, and then transferred to an isolation solution without enzymes to separate egg cells from ovules. The fusion of wheat egg cells with wheat and S. viridis sperm was conducted using an electro-fusion apparatus. Under suitable osmotic pressure (10% mannitol), calcium concentration of 0.001% (CaCl2·2H2O), and a 30-35 V alternating electric field for 15 s, egg cells and sperm adhered to each other and became arranged in a line. Electroporation of the plasma membrane of egg cells and sperm using a 300-500 V direct-current electric field (45 µs amplitude pulse) caused them to fuse.

Morphological changes in starch grains after dehusking and grinding with stone tools

Research on the manufacture, use, and use-wear of grinding stones (including slabs and mullers) can provide a wealth of information on ancient subsistence strategy and plant food utilization. Ancient residues extracted from stone tools frequently exhibit damage from processing methods, and modern experiments can replicate these morphological changes so that they can be better understood. Here, experiments have been undertaken to dehusk and grind grass grain using stone artifacts. To replicate ancient activities in northern China, we used modern stone tools to dehusk and grind twelve cultivars of foxtail millet (Setaria italica), two cultivars of broomcorn millet (Panicum miliaceum) and three varieties of green bristlegrass (Setaira viridis). The residues from both used and unused facets of the stone tools were then extracted, and the starch grains studied for morphological features and changes from the native states. The results show that (1) Dehusking did not significantly change the size and morphology of millet starch grains; (2) After grinding, the size of millet starch grains increases up to 1.2 times larger than native grains, and a quarter of the ground millet starch grains bore surface damage and also exhibited distortion of the extinction cross. This indicator will be of significance in improving the application of starch grains to research in the functional inference of grinding stone tools, but we are unable to yet distinguish dehusked forms from native.

Fabrication of superhydrophobic bionic surface integrating with VOF simulation studies of liquid drop impacting.

Superhydrophobic surface has wide application in self-cleaning, anti-pollution, anti-adhesion, drag reduction, but the stable and efficient manufacture of bionic superhydrophobic surfaces is a challenge. We have reproduced the microscopic structure of natural plants and achieved superhydrophobic surface preparation without chemical modification by mechanical process. This program need many experiments to generate processing parameters based on the bionic surface structure. To solve this problem, based on the natural Green Bristlegrass superhydrophobic surface, an optimized bio-inspired striped configuration was presented and the computational fluid dynamics approach was integrated into the fabrication, which was estimated the superhydrophobicity of bio-inspired surface. The volume of fluid (VOF) model and the Level Set function were used to determine the position of the interface during the liquid impact process by solving the change of the volume fraction of each phase in the mixed fluid, thus tracking the gas-liquid phase interface. According to the simulation of striped surface structure, we have processed the bionic samples successfully and they showed an excellent superhydrophobic property, the contact angle was 154° ± 2° and the sliding angle was <5°. The contact time of bionic sample was 12.8 ms. This article used the VOF simulation method to evaluate the design and parameters of the structure, so that the selection of processing parameters were more optimized. Furthermore, the study was essential to access the bio-inspired design and fabrication procedure of superhydrophobic surface.

From weed to multi-heteroatom-doped honeycomb-like porous carbon for advanced supercapacitors: A gelatinization-controlled one-step carbonization

Biomass-derived porous carbon materials stimulate considerable research interest owing to the abundant resources, low cost, eco-friendliness and effective applications in electrochemical energy storage. Herein, N/S/O-doped honeycomb-like porous carbon materials are successfully controlled prepared from green bristlegrass seeds by one-step carbonization with assistance of gelatinization treatment. Benefitting from their three-dimensional interconnected honeycomb-like hierarchical porous architecture together with high specific surface area and multi-heteroatom doping, the as-synthesized carbon materials exhibit high specific capacitance of 391 F g−1 at a current density of 0.5 A g−1 with good rate capability (67.8% capacitance retention at 50 A g−1) in 6 M KOH and outstanding cycling stability with a capacitance retention of 97.2% over 10000 cycles. Meanwhile, the symmetric supercapacitor device in 1 M Na2SO4 aqueous electrolyte is able to deliver a high energy density of 20.15 Wh kg−1 at a power density of 500 W kg−1 with a wide voltage window of 2.0 V. More impressively, it still retains a high energy density of 15.56 Wh kg−1 even at 20 kW kg−1. In addition, the supercapacitor device also shows superior cycling performance with a 94.2% capacitance retention for 10000 cycles.

エノコログサ(ネコジャラシ)の穂による気管支異物の1例

エノコログサ(ネコジャラシ)の穂による気管支異物の1例

Temporal variation in soil resistance to flowing water erosion for soil incorporated with plant litters in the Loess Plateau of China

Plant litter can be incorporated into topsoil under natural circumstances by soil splash, sediment deposition, and soil-dwelling animal activities. The incorporated litter can change the mechanical properties of soil and the decomposition of the incorporated litter can improve soil structural stability. Those changes likely influence soil detachment process by overland flow. This study was undertaken to quantify the effects of incorporated plant litters into topsoil on the temporal variation in soil resistance to detachment by overland flow using natural soil samples collected from four different plots (one control and three litter incorporation treatments) and then scoured under six different flow shear stresses in a hydraulic flume. The experiment started from April 19 to October 5, 2015 for 10 times at approximately 20days sampling intervals. Soil properties and environmental parameters were also measured at each sampling time to explain the temporal variations in rill erodibility and critical shear stress. The results showed that the incorporated plant litter was effective to enhance soil resistance to flowing water erosion. Compared to bare soil, rill erodibilities of litter incorporated soils of black locust, sea buckthorn, and green bristle grass decreased by 24.3%, 33.5%, and 34.8%. The temporal variations in rill erodibility of bare and litter incorporated soils were similar. Rill erodibility decreased significantly over time as an exponential function for both bare and litter incorporated soils. The relative rill erodibility of three litter incorporated soils increased over time as a power function. The fitted critical shear stress increased exponentially over time. The temporal variations in rill erodibility could be explained by the temporal variations in soil consolidation, water stable aggregate, and litter decomposition. Rill erodibility could be well estimated by soil bulk density, water stable aggregate, and litter mass density (r2=0.92).

ChemInform Abstract: Biomimetic Water‐Collecting Materials Inspired by Nature

AbstractReview: 176 refs.

Biomimetic water-collecting materials inspired by nature.

Nowadays, water shortage is a severe issue all over the world, especially in some arid and undeveloped areas. Interestingly, a variety of natural creatures can collect water from fog, which can provide a source of inspiration to develop novel and functional water-collecting materials. Recently, as an increasingly hot research topic, bioinspired materials with the water collection ability have captured vast scientific attention in both practical applications and fundamental research studies. In this review, we summarize the mechanisms of water collection in various natural creatures and present the fabrications, functions, applications, and new developments of bioinspired materials in recent years. The theoretical basis related to the phenomenon of water collection containing wetting behaviors and water droplet transportations is described in the beginning, i.e., the Young's equation, Wenzel model, Cassie model, surface energy gradient model and Laplace pressure equation. Then, the water collection mechanisms of three typical and widely researched natural animals and plants are discussed and their corresponding bioinspired materials are simultaneously detailed, which are cactus, spider, and desert beetles, respectively. This is followed by introducing another eight animals and plants (butterfly, shore birds, wheat awns, green bristlegrass, the Cotula fallax plant, Namib grass, green tree frogs and Australian desert lizards) that are rarely reported, exhibiting water collection properties or similar water droplet transportation. Finally, conclusions and outlook concerning the future development of bioinspired fog-collecting materials are presented.

Water collection abilities of green bristlegrass bristle

A unique water collection ability is revealed in green bristlegrass bristle that is attributed to a barb array similar to the ratchet structure that is arranged on the cone groove surface of bristle. The multi-level geometric gradients are formed to dominate the coalescence and directionally transport the tiny droplets of condensed water.

Is the Fungus Magnaporthe Losing DNA Methylation?

The long terminal repeat retrotransposon, Magnaporthe gypsy-like element (MAGGY), has been shown to be targeted for cytosine methylation in a subset of Magnaporthe oryzae field isolates. Analysis of the F1 progeny from a genetic cross between methylation-proficient (Br48) and methylation-deficient (GFSI1-7-2) isolates revealed that methylation of the MAGGY element was governed by a single dominant gene. Positional cloning followed by gene disruption and complementation experiments revealed that the responsible gene was the DNA methyltransferase, MoDMT1, an ortholog of Neurospora crassa Dim-2. A survey of MAGGY methylation in 60 Magnaporthe field isolates revealed that 42 isolates from rice, common millet, wheat, finger millet, and buffelgrass were methylation proficient while 18 isolates from foxtail millet, green bristlegrass, Japanese panicgrass, torpedo grass, Guinea grass, and crabgrass were methylation deficient. Phenotypic analyses showed that MoDMT1 plays no major role in development and pathogenicity of the fungus. Quantitative polymerase chain reaction analysis showed that the average copy number of genomic MAGGY elements was not significantly different between methylation-deficient and -proficient field isolates even though the levels of MAGGY transcript were generally higher in the former group. MoDMT1 gene sequences in the methylation-deficient isolates suggested that at least three independent mutations were responsible for the loss of MoDMT1 function. Overall, our data suggest that MoDMT1 is not essential for the natural life cycle of the fungus and raise the possibility that the genus Magnaporthe may be losing the mechanism of DNA methylation on the evolutionary time scale.