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.

五节芒(Miscanthus floridulus)不同种群对镉积累与转运的差异研究

采用盆栽试验的方法,对比研究了来源于大宝山矿区和惠州博罗非矿区的两个五节芒种群在不同Cd含量土壤中的生长反应、Cd富集能力及对土壤Cd形态的影响。结果表明,来源不同的两个五节芒(Miscanthus floridulus)种群植株对土壤中不同浓度的Cd的生长反应不同,低浓度Cd处理,非矿区种群的地上部生物量即受到显著影响,而矿区种群受到的影响不显著。Cd处理浓度提高时,非矿区种群的地上部生物量为对照的30.17%～42.07%,矿区种群地上部生物量为对照的57.80%～67.04%。非矿区种群根部生物量随处理浓度的增加而降低,为对照的57.75%-64.08%,而矿区种群显著升高,为对照的117.43%～135.56%。五节芒矿区种群地上部和根部的Cd含量随着土壤Cd处理浓度的升高而迅速升高,其升高速度明显快于非矿区种群。五节芒矿区种群根部积累的Cd总量远大于非矿区种群,且随着土壤中Cd添加量的增加而显著增加(P<0.05)。随着Cd胁迫程度的加重,五节芒两种群转移系数和耐性指数都有不同程度的下降,矿区种群的转移系数和耐性指数明显高于非矿区种群。Pearson相关性分析发现,五节芒根部生物量与地上部生物量极显著正相关,地上部生物量与根部和地上部Cd含量均呈极显著负相关关系,地上部Cd含量与根部Cd含量及转移系数(Translocation Factor,TF)均呈极显著正相关关系,耐性指数(Tolerant Index,TI)与根部和地上部Cd含量均呈极显著负相关关系,反映了根部和地上部Cd的累积对植物产生了毒性,并对五节芒的生长产生了抑制作用。矿区种群表现出对Cd更强的耐性以及富集作用。

中国芒(Miscanthus sinensis)种质资源SSR标记遗传多样性分析

利用33对SSR引物对来自中国16个省的46份野生芒(Miscanthus sinensis)种质进行遗传多样性分析。结果显示:(1)33对SSR引物共扩增出87条DNA条带,75条为多态性条带,占86.21%,条带大小范围80～310 bp;(2)遗传多样性参数分析结果:Shannon's信息指数(I)变幅为0.020～1.522,平均为0.745,引物多态性信息含量(PIC)变幅为0.040～0.738,平均为0.445,遗传相似系数(GS)的变幅为0.315～0.933,平均为0.569,说明我国芒种质资源遗传基础宽,遗传多样性丰富;(3)相似系数UMPGA聚类结果与主成分分析(PCA)结果一致,可将46份种质分为3大类群,类群Ⅰ主要由中部芒组成,类群Ⅱ主要由北方芒组成,类群Ⅲ主要由南方芒组成,西南芒在每个类群中均有渗透,这一结果说明芒种质资源的遗传分化与其种源的地理分布有一定的相关性,但与地理起源不能完全吻合。

中国芒(Miscanthus sinensis)初级核心种质的构建

以555份芒(Miscanthus sinensis)种质资源为研究对象,根据26个表型性状数据,按地理来源、植物区系和单一性状进行分组,分别采用简单比例法、平方根法和多样性指数法确定组内取样数,再根据聚类和随机2种方法进行组内个体选择。依照上述方案共构建出19个具有代表性的芒初选核心种质样本库。通过平均相似系数、性状符合度、数量性状变异系数和遗传多样性指数等4项检测指标对上述19种构建方案进行比较,最终确定了按"植物区划分组+多样性指数确定取样数+聚类选择个体"为芒初级核心种质构建的最佳方案。通过此方法建立起的芒初级核心种质资源共83份,占总资源的14.95%,且新构建的初级种质资源与总资源性状符合度达到100%。

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.

芒(Miscanthus sinensis)再生体系的建立和优化

以芒(Miscanthus sinensis)的幼穗为材料,通过外植体消毒灭菌、愈伤组织诱导、不定芽分化增殖、生根和驯化移栽,建立芒组织培养的快速繁殖体系。结果表明:芒愈伤组织诱导的最佳培养基是MS+4.0 mg/L 2,4–D+1.0 mg/L 6–BA+0.5 mg/L Cu SO4,愈伤组织诱导频率达99.33%;不定芽分化和增殖的最佳培养基分别为MS+1.0mg/L 6–BA+0.4 mg/L NAA+0.4 mg/L IAA和MS+3.0 mg/L 6–BA+1.5 mg/L PP333+1.0 mg/L CCC,分化率为96%,增殖系数为9.1;生根培养基选用MS+0.5 mg/L IAA+0.5 mg/L NAA+0.5 mg/L CCC+0.5 mg/L PP333,生根率达100%;将再生苗移栽至用黄土和营养土配制的基质上,其成活率高达95%,且生长势良好。

火烧对洞庭湖湿地荻(Miscanthus sacchariflorus)和苔草(Carex brevicuspis)群落土壤性质的影响

火烧作为调控因子,对植物群落结构和生态系统功能具有重要影响,但在湖泊湿地中研究较少.通过野外调查取样与实验室分析,探讨火烧对洞庭湖湿地主要群落类型——荻(Miscanthus sacchariflorus)和苔草(Carex brevicuspis)土壤化学性质的影响.结果表明:火烧后,苔草群落土壤硝态氮含量显著减少64.6%,有机质含量增加26.3%;而荻群落土壤与之相反,硝态氮含量增加186.9%,有机质含量减少22.9%.火烧后,苔草群落的全氮、铵态氮、全碳和全磷含量均显著增加,分别增加了75.4%、36.3%、102.7%和76.9%,而荻群落土壤与对照组间无显著差异.总体上,火烧对荻群落土壤养分影响不大,可作为芦苇场的一种管理方式,但火烧促进苔草群落土壤养分释放,有助于苔草群落提前萌芽和生长,并引起牲畜牧食增加.

芒属(Miscanthus)植物种质资源研究进展

芒属植物属禾本科多年生高大草类,多分布于热带非洲至亚洲东南部。近年来在欧美国家受到广泛的关注,被认为是一种开发潜力巨大的生物质能源。本文查阅近年国内外相关文献,对芒属植物的生境、分布、遗传多样性、光合特性、抗性生理生化、繁殖学、饲草利用以及作为能源植物的研究等方面做了综述,并展望了其研究前景,旨在推动芒属种质资源的研究。

芒(Miscanthus sinensis Anderss)花粉生活力测定方法比较

采用离体萌发法、FDA染色法和I2-KI染色法测定芒离体花粉的生活力,并对测定效果进行比较。结果表明,利用离体萌发法测得芒离体花粉的平均初始萌发率为82.6%,并且花粉萌发和生长很快,5min即开始萌发,培养30min后花粉管平均长度达到了145.77μm,但花粉的平均萌发率下降很快,室温保存90min的花粉其萌发率已下降至3.0%。利用FDA染色法和I2-KI染色法测定的芒花粉初始生活力与离体萌发法的结果基本一致,分别为84.6%和86.6%,但这两种染色法在跟踪测定芒离体花粉的生活力时易误判,不适合用于跟踪测定花粉生活力的变化。利用离体萌发法能够准确有效地测定芒花粉生活力的变化规律,而FDA染色法和I2-KI染色法适合用于测定芒花粉的初始生活力。

基于生物质能的芒属(Miscanthus)植物碳动态和收支研究进展

生物质能(Biomass energy)是最为广泛的可再生能源,其中多年生芒属C4植物(Miscanthus)由于具有巨大碳固定能力而成为潜力巨大的生物质能植物。中国是芒属植物芒草起源中心,但相对于欧洲国家应对能源危机和温室效应而采取的芒草研究与应用来说,仍处于起步阶段。我国长期以来传统的草地利用模式,决定了在南方草地的研究显著少于北方,近年来芒草在华南地区的运用研究集中于生态修复,对草本植物群落基于生态系统水平的CO2气体交换能力的研究仍然相当缺乏,在二氧化碳浓度持续增长及全球变暖背景下,生物质能植物及其碳汇功能的相关研究尤显重要。我国南方近6 700万hm2退化丘陵草坡急待恢复或处于恢复中,草坡地芒属植物符合生物质能植物标准,施肥少,害虫少,农药输入少,能够有效地利用光、水等自然资源。考虑到C4植物具有比C3植物更强的光合作用能力,高光能利用率C4芒属植物的碳固定能力及能源潜力值得重视,但缺乏科学的碳动态和碳收支评估。综述了国内外芒草生物量特征与生物质能潜力研究现状,重点论述芒属植物生态系统水平的碳动态和收支能力研究,探讨了系统水平更客观评估芒属碳源汇(Carbon sequestration)功能的方法,基于生物量过程的研究结果及华南地区草坡研究历史和现状,为草坡地生物质能的合理开发利用提出了相关对策,强调在我国南方开发和利用芒属植物资源具有重要能源价值和经济、环境效益。

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.

淹水胁迫对水库消落带五节芒(Miscanthus floridulus)根际土壤酶活性的影响

五节芒(Miscanthus floridulus)是一种广泛分布于我国亚热带地区的乡土植物,具有耐涝抗旱降污的特性。以五节芒为试验材料,通过盆栽模拟实验,研究其在浙南山地水库消落带生境与非消落带生境中生长的五节芒植株在经受长时间淹水胁迫后,植株根际土壤酶活性的变化动态。结果表明:随着淹水时间的延长,消落带生境和非消落带生境中五节芒根际土壤过氧化氢酶、蔗糖酶、酸性磷酸酶活性都呈下降趋势。消落带生境中的过氧化氢酶活性始终高于非消落带生境中的过氧化氢酶活性,而根际土壤蔗糖酶和酸性磷酸酶活性要始终低于非消落带生境。说明消落带生境中生长的五节芒在淹水条件下,对土壤中有毒物质过氧化氢的清除能力要大于非消落带生境。而消落带生境中相对低的蔗糖酶和酸性磷酸酶活性能缓慢消耗淹水植株体内贮存的营养物质和能量,提高五节芒植株的抗淹能力。

铅胁迫下不同生态型五节芒(Miscanthus floridulus)的抗氧化系统的差异研究

为揭示不同生态型五节芒在抵抗Pb胁迫机制方面的异同,以粤北大宝山矿山开采地优势植物五节芒(Miscanthus floridulus)为试验材料,比较了五节芒非矿山生态型(采自惠州市博罗县丘陵山地)和矿山生态型(采自大宝山矿区)在相同Pb质量分数下的生理响应。Pb胁迫会导致五节芒叶片MDA的积累,非矿区生态型五节芒MDA积累的幅度要大于矿区种群。非矿区生态型五节芒叶片中SOD的活性被Pb胁迫抑制,POD活性都受到Pb胁迫的诱导比对照有所增加,但矿区生态型增加的幅度要大于非矿区生态型,矿区生态型植株两种酶的活性在最高w(Pb)时都显著高于非矿区生态型植株。随Pb处理质量分数增大,非矿区种群五节芒叶片中PPO的活性呈先增加再下降的趋势,矿区生态型则显著增加,在最高w(Pb)处理时活性要显著高于非矿区生态型。表明矿山型五节芒的耐重金属Pb要强于非矿山型。

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.

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.

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.

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.

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.