Evaluation of Pre-Emergence and Post-Emergence Herbicides for Weed Management in Miscanthus sacchariflorus and Miscanthus sinensis

Miscanthus,is a promising bioenergy crop,considered superior to other bioenergy crops because of its higher water and nutrient use efficiency,cold tolerance,and higher production of biomass.Broadleaf weeds and grass weeds,cause major problems in the Miscanthus field.A field experiment was conducted in 2018 and 2019,to assess the effects of pre-emergence(alachlor and napropamide)and post-emergence herbicides(nicosulfuron,dicamba,bentazon,and glufosinate ammonium)on broadleaf and grass weeds in M.sinensis and M.sacchariflorus fields.The weed control efficiency and phytotoxicity of pre-and post-emergence herbicides were evaluated at 30 days after treatment(DAT)and compared to those of the control plots.The results showed wide variations in the susceptibility of the weed species to the treated herbicides.Treatment with nicosulfuron 40 g.a.i.ha^(-1) provided the most effective overall weed control(with 10%visual injury),without affecting the height and biomass of neither Miscanthus species in the field.Post-emergence herbicides such as glufosinate ammonium 400 g.a.i.ha^(-1) and dicamba 482 g.a.i.ha^(-1) were effective and inhibited the growth and density of the majority of weeds to a 100%;however,they showed significant phytotoxicity(toxicity scale of 1-10)to both species of Miscanthus.The application of glufosinate ammonium caused severe injuries to the foliar region(90%visual injury)of both Miscanthus sps.Comparatively,M.sinensis showed a slightly higher tolerance to the herbicides nicosulfuron,bentazon and napropamide with 10%visual injury at the recommended dose than M.sacchariflorus.The present study clearly showed that infestation of broadleaf and grass weeds in Miscanthus fields can cause significant damage to the growth and biomass of Miscanthus and applying pre-emergence and post-emergence herbicides effectively controls the high infestation of these weeds.

Analysis of Chromosome Karotype of Miscanthus sinensis

The number and karyotype of Miscanthus sinensis chromosome was researched with root tip squash method. The formula for karyotype is 2n =2x=48 =26m ＋16Sm ＋6St and belonged to the type of 2C. The number of Miscanthus sinensis chromosome is 2n=48. The basic number of chromosome is x=24.

Enhanced Enzymatic Hydrolysis of Miscanthus sinensis Following Synergic Pretreatment with ^(60)Co γ-ray Irradiation and Alkaline Hydrogen Peroxide

[Objective] This study aimed to investigate the effects of different pretreat- ments on enzymatic saccharification of Miscanthus sinensis and improve reducing sugar yield in the enzymolysis process. [Method] M. sinensis was pretreated with 60Co y-ray irradiation and alkaline hydrogen peroxide, to analyze their effects on re- ducing sugar yield of enzymatic hydrolysis. [Result] After pretreatment with 400 kGy 60Co y-ray irradiation, reducing sugar yield in the enzymolysis process of M sinensis was 76.24 mg/g; after synergic pretreatment with 400 kGy 60Co y-ray irradiation and alkaline hydrogen peroxide, reducing sugar yield in the enzymolysis process of M. sinensis was 505.08 mg/g, which was improved by 5.6 times compared to that in pretreatment with 400 kGy 60Co y-ray irradiation. Based on process optimization, the optimal hydrolysis conditions were obtained： pretreatment temperature 30 ℃, NaOH concentration 1.2%, hydrogen peroxide concentration 2%, pretreatment time 6 h. [Conclusion] Synergic pretreatment with 60Co y-ray irradiation and alkaline hydrogen peroxide could significantly improve reducing sugar yield in the enzymolysis process of M. sinensis, which provided a new theoretical basis for preparing fuel ethanol with M. sinensis.

Sweet sorghum and Miscanthus：Two potential dedicated bioenergy crops in China

Among the potential non-food energy crops,the sugar-rich C4 grass sweet sorghum and the biomass-rich Miscanthus are increasingly considered as two leading candidates.Here,we outline the biological traits of these energy crops for largescale production in China.We also review recent progress on understanding of plant cell wall composition and wall polymer features of both plant species from large populations that affect both biomass enzymatic digestibility and ethanol conversion rates under various pretreatment conditions.We finally propose genetic approaches to enhance biomass production,enzymatic digestibility and sugar-ethanol conversion efficiency of the energy crops.

Controllable synthesis of nitrogen-doped porous carbon from metal-polluted miscanthus waste boosting for supercapacitors

High-value reclamation of metal-polluted plants involved in phytoremediation is a big challenge.In this study,nitrogen-doped nanoporous carbon with large specific area of 2359.1 m^(2)g^(-1) is facilely fabricated from metal-polluted miscanthus waste for efficient energy storage.The synergistic effect of KOH,urea and ammonia solution greatly improve the nitrogen quantity and surface area of the synthesized carbon.Electrodes fabricated with this carbon exhibit the excellent capacitance performance of 340.2 F g^(-1) at 0.5 A g^(-1) and a low combined resistance of 0.116Ω,which are competitive with most of previously reported carbon-based electrodes.In addition,the as-obtained carbon electrode shows a high specific capacitance retention of over 99.6%even after 5000 cycles.Furthermore,the symmetric supercapacitor fabricated using the synthesized carbon achieves a superior energy density of 25.3 Wh kg^(-1)(at 400 W kg^(-1))in 1 mol L^(-1) Na_(2)SO_(4)aqueous solution.This work provides an efficient route to upcycle metal-polluted plant waste for supercapacitor applications.

Effect of the Pre-Treatment Severity on the Antioxidant Properties of Ethanol Organosolv Miscanthus x giganteus Lignin

The effect of the severity of an organosolv treatment of Miscanthus x giganteus on antioxidant capacity of the obtained lignin was studied. Four organosolv lignins extracted with different severity conditions were chosen and tested. Results obtained using the methyl linoleate method have shown a correlation between oxygen uptake index and the combined severity. It was found that lignin extracted at higher severity pre-treatment and with a higher phenolic hydroxyl content, lower aliphatic hydroxyl content, molecular weight and polydispersity has the highest antioxidant capacity.

Differential Responses of NHX1 and SOS1 Gene Expressions to Salinity in two Miscanthus sinensis Anderss.Accessions with Different Salt Tolerance

The lignocellulosic crop Miscanthus spp.has been identified as a good candidate for biomass production.The responses of Miscanthus sinensis Anderss.to salinity were studied to satisfy the needs for high yields in marginal areas and to avoid competition with food production.The results indicated that the relative advantages of the tolerant accession over the sensitive one under saline conditions were associated with restricted Na^(+)accumulation in shoots.Seedlings of two accessions(salt-tolerant‘JM0119’and salt-sensitive‘JM0099’)were subjected to 0(control),100,200,and 300 mM NaCl stress to better understand the salt-induced biochemical responses of genes involved in Na^(+)accumulation in M.sinensis.The adaptation responses of genes encoding for Na^(+)/H^(+)antiporters,NHX1 and SOS1 to NaCl stress were examined in JM0119 and JM0099.The cDNA sequences of genes examined were highly conserved among the relatives of M.sinensis based on the sequencing on approximate 600 bp-long cDNA fragments obtained from degenerate PCR.These salt-induced variations of gene expression investigated by quantitative real-time PCR provided evidences for insights of the molecular mechanisms of salt tolerance in M.sinensis.The expression of NHX1 was up-regulated by salt stress in JM0119 shoot and root tissues.However,it was hardly affected in JM0099 shoot tissue except for a significant increase at the 100 mM salt treatment,and it was salt-suppressed in the JM0099 root tissue.In the root tissue,the expression of SOS1 was induced by the high salt treatment in JM0119 but repressed by all salt treatments in JM0099.Thus,the remarkably higher expression of NHX1 and SOS1 were associated with the resistance to Na^(+)toxicity by regulation of the Na^(+)influx,efflux,and sequestration under different salt conditions.

Dual-Use Bioenergy-Livestock Feed Potential of Giant Miscanthus, Giant Reed, and Miscane

High yielding perennial grasses could integrate bioenergy-livestock operations, thereby, offsetting diversions of cropland to lignocellulosic crops, but research is needed to determine chemical composition and digestibility of leaf and stem fractions that might affect downstream reside uses. The objective of this study was to compare feedstock quality of leaf and stem tissues of dedicated bioenergy feedstocks: giant miscanthus (Miscanthus × giganteus), giant reed (Arundo donax), and miscane (Saccharum hybrid × Miscanthus spp.) when grown with or without supplemental irrigation on an upland site. Three species were space-planted on a silt loam soil in March 2007 and harvested prior to the first freeze in plant-cane, first ratoon, and second-ratoon crops for three years. Giant miscanthus leaf tissue had greatest acid detergent lignin and cellulose, and lowest concentrations of nitrogen (N) and total nonstructural carbohydrates (TNC) in ratoon crops. Giant reed leaf tissue had greatest concentrations of in vitro digestible dry matter (IVDMD), TNC, and N (P ≤ 0.05). Conversely, miscane stem tissue had greatest concentrations of IVDMD, TNC, hemicellulose, and low dry matter and combustible energy (P ≤ 0.05). Results suggest all species’ residue has positive feedstock attributes for thermochemical bioenergy conversion, and albeit giant miscanthus has very little potential value as fodder. Miscane stem and giant reed leaf tissue have potential value as livestock feed, although giant reed is not currently recommended for planting. Further research is needed on dietary composition, acceptability, voluntary intake, and live weight gain before any of these species are recommended as livestock feed sources.

A new form of Miscanthus (Chinese silver grass, Miscanthus sinensis—Andersson) as a promising source of cellulosic biomass

The Far East population of Miscanthus sinensis (Andersson) was introduced into the West Siberia conditions. There was distinguished a form with a modified structure of the rootage which forms long shoots with leader buds and rapidly colonizes soil, thus forming a continuous and flat (without tussocks) plantation of miscanthus. It is shown that using usual agrotechnologies, it is possible to obtain 10-15 tons of dry biomass of high quality cellulose (about 40%) per ha/year.

Sustainable Land Management: Growing Miscanthus in Soils Contaminated with Heavy Metals

Miscanthus grows well in some marginal and contaminated soils, and it has the potential to be used as a biofuel. Copper and cobalt are heavy metals that sometimes are present as contaminants in soils at concentrations that may impact the safety of products that are harvested. Laboratory research has been conducted with Miscanthus sacchariflorus M. to investigate metal uptake of copper and cobalt because metal concentrations in the harvested parts of miscanthus are important for biofuel applications. The results show that the use of miscanthus for biofuel from soil contaminated by heavy metals depends mainly on the nature of contaminated metals: cobalt was detected only for highest treated concentration of metal and mainly in the roots. The highest concentration of copper was detected in the roots however this metal was detected in stems and leaves of miscanthus as well. Miscanthus biomass harvested from cobalt contaminated soil may be used for energy production because the harvested part accumulated only limited traces of the metal. The experimental results are in reasonable agreement with other results from the literature.

Growth Rates of Giant Miscanthus (<i>Miscanthus</i>×<i>giganteus</i>) and Giant Reed (<i>Arundo donax</i>) in a Low-Input System in Arkansas, USA

The US Department of Energy is currently building strategies for the expansion of clean and renewable energy sources, and tall, rapidly-growing grasses such as giant miscanthus (Miscanthus × giganteus) and giant reed (Arundo donax) are two of the many of species that could fill this renewable energy niche. The objective was to compare stalk growth components of giant miscanthus and giant reed, in a low-input system (no irrigation and no fertilizer use) in Arkansas, USA. Due to the potential invasiveness of giant reed, our study was conducted on an upland site to minimize escape. Plant height and dry weight per stalk were measured every week for two consecutive growing seasons in 2012 and 2013. Leaf area index (LAI) was measured every two weeks from May to September in 2012. A significant species × day interaction occurred for plant height and dry weight per stalk, due to the relatively greater height and weight of giant reed compared to giant miscanthus after May. Stalk elongation rate was greater for giant reed than giant miscanthus (1.85 and 1.11 cm day-1, respectively). Leaf area index differed between species, giant reed (10.4 m2 m-2) > giant miscanthus (4.4 m2 m-2). We showed that giant reed produced taller, heavier stalks, and had a greater stalk elongation rate, compared to giant miscanthus. For sustainable bioenergy production from giant reed in Arkansas, further studies should be performed to determine ideal number of harvests per year and associated production cost.

Changing the Moisture Content of the Spartina and Miscanthus and Willow Shoots during Storage in Natural Conditions

The aim of this study was to determine the characteristics of the distribution of energy plant moisture content along the height of their shoots and the dynamics of moisture during storage in natural conditions. The shoots of Spartina, Miscanthus and willow were used in the study. Entire shoots were cut into sections of 10 cm and for each set in monthly cycles for six months moisture content was evaluated. After a month＇s storage of freshly cut shoots the biggest decrease of content moisture in the shoots of Spartina and Miscanthus was recorded, by 31% and 22%, respectively, and the lowest in willow shoots （12%）. After sixth months of shoots storage the lowest moisture content （10%-12%） was reached in miscanthus. The most uneven moisture content along the height of shoots Spartina was characterized because on one third of the height from the bottom, the moisture content of shoots was 20%, and the top had moisture content in the range 5%-10%. Willow shoots were characterized by the smallest drop in moisture, and the final moisture content was about 23%, with the top part of moisture content of 10%-20%. The dynamics of moisture change during the six months of storage of grass shoots （Miscanthus and Spartina） in natural conditions under roofing was described by one power function regression, and willow by another one. Empirical models can be used to predict changes in moisture content of these plants in experiment conditions, since the coefficients of determination were 94.66% and 89.18%, respectively.

An Experimental Investigation of Fluidized Bed Gasification of Biomass Blended from Wood, Miscanthus, Straw and other Industrial Bioresidues

In order to identify potential wood substitutes for the production of energy by gasification, binary blends （wood/miscanthus, miscanthus/straw and wood/straw） and ternary blends （wood, miscanthus and organic residue） were systematic tested in a laboratory bubbling fluidized bed gasification system. The results of experiments were compared with results of wood gasification. Of the binary blends, wood and miscanthus exhibited great potential as a wood substitute in fluidized bed gasification in terms of process stability and product gas quality. Adding 10 wt. % of organic residues to form ternary blends further improved the product gas quality. Gasification of fuels blended with straw tended to agglomerate in the fluidized bed because of straw＇s low ash melting temperature. This can be counteracted by adding Ca（OH）2 to fuels. Nonetheless, fuels blended with straw with higher percentages of Ca（OH）2 need further study to establish the optimal additive ratio.

Natural Radioactivity in Miscanthus floridulu Plant from the Uranium Tailing Pile at Guangdong, South China

Large amounts of uranium waste rocks and tailings resulting from the exploitation and treatment of uranium ore at the Northern Guangdong mine (South China) have been accumulated in dams (tailing ponds). To reduce the dispersion of natural radionuclides into the environment, some dams were revegetated with arbor, bush and sward. Besides these plants, Miscanthus floridulu is the dominant plant growing in some of the dams. The uptake and distribution of naturally occurring uranium (238U), thorium (232Th), radium (226Ra) and potassium (40K) by Miscanthus floridulu plant from different sample sites of uranium mine were studied under native conditions. The bioconcentration factors (BCFs) of soil to Miscanthus floridulu above-ground and root were calculated and observed to be in the range of 0.14 to 7.74 and 2.71 to 17.83 for 238U, 0 to 3.02 and 0 to 3.29 for 232Th, 0.15 to 79.76 and 1.01 to 50.22 for 226Ra and 3.00 to 8.41 and 2.69 to 11.22 for 40K, respectively. The transfer factors (TFs) of Miscanthus floridulu root to aboveground were also calculated and observed to be in the range of 0.01 to 0.73 for 238U, 0 to 0.99 for 232Th, 0.08 to 1.50 for 226Ra and 0.57 to 1.94 for 40K, respectively. The results showed that, Miscanthus floridulu is 238U and 226Ra-accumulating plant with significant absorption and accumulation characteristics.

Optimization of Liquid Ammonia Treatment for Enzymatic Hydrolysis of Miscanthus sinensis Anderss

Miscanthus biomass yield high, high photosynthetic efficiency, fast growth, easy breeding, widely distributed, is suitable as raw materials for the production of fuel ethanol. In this paper, the method of the pretreatment of liquid ammonia for Miscanthus, using the pretreatment of liquid ammonia to overcome biomass recalcitrance, adding cellulase enzyme, and the monosaccharide content is determined by using high performance liquid chromatography (HPLC). Effect of pretreatment process on the enzyme solution effect of awn, conducts the research to the water processing rate, temperature, residence time, amount of ammonia, the amount of H2O2 parameters. Data shows that, in the moisture content of 80%, temperature 130?C, loading amount of ammonia 2:1, residence time 10 min, the glucan and xylan enzyme conversion rate are 73.23% and 73.28% respectively. After a mass balance, dry base mans per 100 g can get glucose 28.96 g and xylan 17.25 g.

Landscape Application of Six Ornamental Grass Species of Miscanthus

Ornamental grasses of Miscanthus have won increasing popularity for its outstanding ornamental and ecological value.Ornamental features,ecological characters and gardening application of 6 ornamental grass species of Miscanthus were explored to provide the theoretical basis for playing their role in landscape construction.

Plant Resources of Miscanthus in Yuncheng Region

Some Miscanthus species are potential plant resources for energy and industry.The three high-growing species which originated in China, i. e. M. floridulus, M. sacchariflorus, M. sinensis, now still distribute--or at least have ever been planted--inYuncheng region, though they are decreasing in their community and individual numbersrapidly in the latest decades due to the human activities such as land exploitation and agriculture. According to our investigation it is clear that Yuncheng region is a transition or overlapping area for various species and geographic varieties of these plants. It is approrpriate tobuild a gene pool in this region to collect and to protect Miscanthus resources.It will be discussed respectively for the three species as follows:

‘细叶’芒(Miscanthus sinensis’Variegatus’)四倍体诱导与表型分析

本研究以观赏植物二倍体‘细叶’芒的幼穗为外植体诱导出愈伤组织,采用秋水仙素诱导处理获得其同源四倍体,分别通过流式细胞仪检测和根尖细胞染色体计数鉴定再生植株的倍性。进一步对四倍体‘细叶’芒的叶片气孔特征和植株表型特征分析,结果表明,与其二倍体亲本相比,四倍体叶片下表皮的气孔密度显著降低而气孔大小明显增大,四倍体植株的株高、分蘖和冠幅显著降低,但是叶片宽度比二倍体植株明显增加,而四倍体茎粗和叶长跟二倍体植株无明显差异。该研究获得的‘细叶’芒同源四倍体可为观赏植物新品种的培育提供新种质资源。

Root-associated(rhizosphere and endosphere) microbiomes of the Miscanthus sinensis and their response to the heavy metal contamination

The plant root-associated microbiomes, including both the rhizosphere and the root endosphere microbial community, are considered as a critical extension of the plant genome. Comparing to the well-studied rhizosphere microbiome, the understanding of the root endophytic microbiome is still in its infancy. Miscanthus sinensis is a pioneering plant that could thrive on metal contaminated lands and holds the potential for phytoremediation applications. Characterizing its root-associated microbiome, especially the root endophytic microbiome, could provide pivotal knowledge for phytoremediation of mine tailings. In the current study, M. sinensis residing in two Pb/Zn tailings and one uncontaminated site were collected. The results demonstrated that the metal contaminant fractions exposed strong impacts on the microbial community structures. Their influences on the microbial community, however, gradually decreases from the bulk soil through the rhizosphere soil and finally to the endosphere, which resulting in distinct root endophytic microbial community structures compared to both the bulk and rhizosphere soil. Diverse members affiliated with the order Rhizobiales was identified as the core microbiome residing in the root of M. sinensis. In addition, enrichment of plant-growth promoting functions within the root endosphere were predicted, suggesting the root endophytes may provide critical services to the host plant. The current study provides new insights into taxonomy and potential functions of the root-associated microbiomes of the pioneer plant, M. sinensis, which may facilitate future phytoremediation practices.

Physiological and biochemical characteristic of Miscanthus×giganteus grown in heavy metal-oil sludge co-contaminated soil

The effect of oil sludge and zinc,present in soil both separately and as a mixture on the physiological and biochemical parameters of Miscanthus×giganteus plant was examined in a pot experiment.The opposite effect of pollutants on the accumulation of plant biomass was established:in comparison with uncontaminated control the oil sludge increased,and Zn reduced the root and shoot biomass.Oil sludge had an inhibitory effect on the plant photosynthetic apparatus,which intensified in the presence of Zn.The specific antioxidant response of M.×giganteus to the presence of both pollutants was a marked increase in the activity of superoxide dismutase(mostly owing to oil sludge)and glutathione-S-transferase(mostly owing to zinc)in the shoots.The participation of glutathione-S-transferase in the detoxification of both the organic and the inorganic pollutants was assumed.Zn inhibited the activity of laccase-like oxidase,whereas oil sludge promoted laccase and ascorbate oxi-dase activities.This finding suggests that these enzymes play a part in the oxidative detox-ification of the organic pollutant.With both pollutants used jointly,Zn accumulation in the roots increased 6-fold,leading to increase in the efficiency of soil clean-up from the metal.In turn,Zn did not significantly affect the soil clean-up from oil sludge.This study shows for the first time the effect of co-contamination of soil with oil sludge and Zn on the phys-iological and biochemical characteristics of the bioenergetic plant M.×giganteus.The data obtained are important for understanding the mechanisms of phytoremediation with this plant.