Effect of mutations on acetohydroxyacid synthase(AHAS)function in Cyperus difformis L.

Cyperus difformis L.is a troublesome weed in paddy fields and has attracted attention due to its resistance to acetohydroxyacid synthase(AHAS)inhibitors.It was found that the amino acid mutation in AHAS was the primary cause for the resistance of Cyperus difformis.However,the effect of different mutations on AHAS function is not clear in Cyperus difformis.To confirm the effect of mutations on AHAS function,six biotypes were collected,including Pro197Arg,Pro197Ser,Pro197Leu,Asp376Glu,Trp574Leu and wild type,from Hunan,Anhui,Jiangxi and Jiangsu provinces,China and the function of AHAS was characterized.The AHAS in vitro inhibition assay results indicated that the mutations decreased the sensitivity of AHAS to pyrazosulfuron-ethyl,in which the I_(50)(the half maximal inhibitory concentration)of wild type AHAS was 0.04μmol L^(-1)and Asp376Glu,Pro197Leu,Pro197Arg,Pro197Ser and Trp574Leu mutations were 3.98,11.50,40.38,38.19 and 311.43μmol L^(-1),respectively.In the determination of enzyme kinetics parameters,the Km and the maximum reaction velocity(Vmax)of the wild type were 5.18 mmol L^(-1)and 0.12 nmol mg^(-1)min^(-1),respectively,and the Km values of AHAS with Asp376Glu,Trp574Leu,Pro197Leu and Pro197Ser mutations were 0.38-0.93 times of the wild type.The Km value of the Pro197Arg mutation was 1.14times of the wild type,and the Vmax values of the five mutations were 1.17-3.33-fold compared to the wild type.It was found that the mutations increased the affinity of AHAS to the substrate,except for the Pro197Arg mutation.At a concentration of 0.0032-100 mmol L^(-1)branched-chain amino acids(BCAAs),the sensitivity of the other four mutant AHAS biotypes to feedback inhibition decreased,except for the Pro197Arg mutation.This study elucidated the effect of different mutations on AHAS function in Cyperus difformis and provided ideas for further study of resistance development.

Effects of Papyrus Plants (Cyperus papyrus) on the Physicochemical Parameters and Nutrient Levels of Water and Sediments in Yala Swamp Wetland in Western Kenya

Yala swamp wetland is the largest fresh water wetland ecosystem in Kenya supporting a broad biodiversity. It comprises of River Yala, the Yala swamp, Lakes Kanyaboli, Namboyo and Sare, and a portion of Lake Victoria neighboring the swamp. Approximately 2300 ha of land have been reclaimed and has been used for large-scale agriculture resulting in mass destruction of papyrus to create room for framing. Papyrus are known to be important in phytoremediation but despite this role information is limited, lacks supportive evidence and the empirical aspect on the levels of these pollutants in relation to the papyrus biomass is limited. The study is aimed at determining the effects of Cyperus papyrus on the water and sediment quality in Yala Swamp wetland. Six sampling sites were purposefully selected to monitor the variations of the physicochemical parameters (temperature, dissolved oxygen: DO, pH, biological oxygen demand: BOD, total suspended solids: TSS, turbidity, electrical conductivity: EC and total dissolved solids: TSS) and the levels selected nutrients (phosphorus and nitrates) in water and sediments as River Yala flows through Dominion Farms, Lake Sare which surrounded by Cyperus papyrus and finally into Lake Victoria. The samples were collected in triplicates during the wet and dry seasons (May and September 2015 respectively). The physicochemical parameters were measured in situ using a Hydrolab muiltimeter while the nutrients were analyzed using UV/Vis spectroscopy. Statistical analysis was done using SAS V9.0 software. The mean temperature was 26.19˚C ± 0.71˚C, DO: 3.72 ± 1.02 Mg/l, BOD: 3.9 ± 0.32 Mg/l, pH: 7.52 ± 0.17, TDS: 109 ± 86.33, EC: 173.26 ± 13.8 μS/cm, TSS: 12.42 ± 18.51 Mg/l and Turbidity: 12.29 ± 10.03 NTU. The values varied significantly at P 0.05 among all the sites. The results show that papyrus is useful in maintaining the required levels of physicochemical parameters. The study will assist in conservation of the papyrus to help phytoremediate pollutants from Dominion farms and the adjacent farms in order to have ecologically sound wetland.

Microbiological Quality of Cyperus esculentus L. Products Sold in Ouagadougou and Bobo Dioulasso (Burkina Faso)

This study aimed to assess the microbiological quality of tiger nut (Cyperus esculentus L.) products sold in Ouagadougou and Bobo Dioulasso. The microbial load of tubers and tiger nut milk was determined using ISO 4833-1 (2003) standard (total mesophilic aerobic flora), NF ISO 7954 (1998) standard (yeasts and molds), and ISO 4832 (2006) standard (total coliforms, thermotolerant coliforms). The results showed that tiger nut tubers had an average microbial load between 4.86 ± 7.03 × 106 UFC/g and 1.82 ± 2.30 × 107 UFC/g for total mesophilic aerobic flora, from 4.34 ± 10.6 × 105 UFC/g to 3.52 ± 4.54 × 106 UFC/g for yeasts and molds, from 2.23 ± 2.25 × 105 UFC/g to 1.41 ± 2.16 × 105 UFC/g for total coliforms and from 1.83 ± 2.03 × 105 UFC/g to 7.0 ± 10.8 × 104 CFU/g for thermotolerant coliforms. For tiger nut milk samples, the average microbial load varied from 3.48 ± 2.98 × 106 CFU/g to 2.80 ± 5.69 × 107 CFU/g for total mesophilic aerobic flora, from 5.00 ± 7.21 × 104 CFU/g to 1.88 ± 3.31 × 105 CFU/g for yeasts and molds, from 4.58 ± 10.4 × 104 CFU/g to 6.31 ± 9.17 × 105 CFU/g for total coliforms and 7.00 ± 7.00 × 103 CFU/g to 2.87 ± 5.86 × 105 CFU/g for thermotolerant coliforms. This study revealed that the tubers and tiger nut milk sold in Ouagadougou and Bobo Dioulasso had a high microbial load which could lead to the degradation of these products and food poisoning for consumers.

Synergistic Mixture of Cyperus esculentus, Phoenix dactylifera and Cocos nucifera Aqueous Extract: Its Liver and Kidney Benefits in Male Albino Rat Model

Background: The synergistic mixture of Cyperus esculentus, Phoenix dactylifera and Cocos nucifera (STCD) aqueous extract is a common drink in Port Harcourt, Nigeria. It is assumed to have various health benefits. However, the synergistic mixture of the content has not been studied scientifically, hence the need to evaluate its effect on the liver and kidney being part of the body’s metabolic organs. Aim: This study evaluated the synergistic mixture of Cyperus esculentus, Phoenix dactylifera and Cocos nucifera (STCD) aqueous extract in male albino rats. Methods: Acute toxicity LD50 of STCD was carried out, afterwards, fifteen male albino rats were grouped into three groups with 5 rats in each group;Control, 200 mg/kg, 400 mg/kg STCD. The rats were administered STCD orally 24 hourly, for 21 days, with feed and water ad libitum. At the end of the experiment, blood samples were collected for biochemical analysis of the liver and kidney biomarkers, while the liver and kidney tissues were harvested for histopathological examination using standard laboratory methods. Descriptive statistics were computed and expressed as Mean ± SD. One-way ANOVA and Turkeys test was performed. P value ≤0.05 was considered statistically significant. Results: Acute toxicity LD50 of STCD was observed to be ≥2404.2 mg/kg body weight. An increase in the percentage body weight difference of 8.39% and 2.86% was observed for 200 and 400 mg/kg STCD groups. Also, the liver weight was observed to increase in 400 mg/kg (3.92 ± 1.42) in comparison to the control group (3.48 ± 1.61), a decrease in the kidney weight was observed in all groups administered STCD in comparison to the control group. Administration of STCD at both 200 and 400 mg/kg revealed a decrease in the concentration of the hepatic biomarkers AST, ALT, ALP, TP, Albumin, Total and conjugated bilirubin. The kidney biomarker Urea was observed to decrease in concentration for 200 mg/kg STCD (4.60 ± 1.83) and 400 mg/kg STCD (4.76 ± 0.74) when compared to the control group (6.32 ± 2.74). A decrease in Creatinine was observed in 200 mg/kg (91.80 ± 34.69) and 400 mg/kg (98.60 ± 15.53) in comparison to the control group (117.60 ± 42.88). The histological examination of the liver of rats administered STCD revealed structural normal central vein, hepatocytes and portal tract. The kidney examination revealed normal glomeruli and normal tubule. Conclusion: The findings of this study opine that STCD improved the health of both the liver and kidney as evidenced via the biomarkers and histological examinations of the liver and kidney. This study therefore recommends the intake of STCD at moderate doses for improved liver and kidney function due to its bioactive compounds and nutritional content.

WEPS模型在乌兰布和沙漠油莎豆(Cyperus esculentus)种植区的应用

为探究WEPS模型的风蚀预测效果,在内蒙古乌兰布和沙漠油莎豆(Cyperus esculentus)种植区,对全采收(CK)、留4采6、留6采6油莎豆纯作和油莎豆-梭梭间作留茬4种不同采收模式地表进行风蚀监测,并利用2020年11月15日和12月26日2次实测风蚀数据对WEPS模型风蚀预测结果进行验证。结果表明:(1)与全采收相比,3种留茬模式均能有效降低风力对种植区地表的侵蚀作用,地表防风固沙能力随留茬数量的增加而提高。(2)WEPS模型预测单宽风蚀量与实测结果有明显差异,模型值最大为实测值的10.16倍,最小为实测值的0.58倍;模型预测质量有不确定性,在植被覆盖度较高的地表预测效果较差。(3)模型预测的单宽输沙量随实测值的增加呈幂函数增加,能够较准确地预测不同地表特征风蚀量变化趋势;在风蚀定量化估算上,WEPS模型还需根据实际风蚀环境对公式及参数进行修正。

Neuroprotection of Cyperus esculentus L. orientin against cerebral ischemia/reperfusion induced brain injury

Orientin is a flavonoid monomer.In recent years,its importance as a source of pharmacological active substance is growing rapidly due to its properties such as anti-myocardial ischemia,anti-apoptosis,anti-radiation,anti-tumor,and anti-aging.However,the neuroprotective effects of Orientin on stroke injury have not been comprehensively evaluated.The aim of the present study was thus to investigate the neuroprotective capacity and the potential mechanisms of Cyperus esculentus L.orientin(CLO)from Cyperus esculentus L.leaves against ischemia/reperfusion(I/R)injury using standard orientin as control.For in vitro studies,we treated HT22 cells with CoCl2 as an in vitro ischemic injury model.HT22 cells in the control group were treated with CoCl2.For in vivo studies,we used rat models of middle cerebral artery occlusion,and animals that received sham surgery were used as controls.We found that CLO protected CoCl2-induced HT22 cells against ischemia/reperfusion injury by lowering lipid peroxidation and reactive oxygen species formation as well as decreasing protein oxidation.However,CLO did not reduce the release of lactate dehydrogenase nor increase the activity of superoxide dismutase.Results showed that CLO could decrease neurological deficit score,attenuate brain water content,and reduce cerebral infarct volume,leading to neuroprotection during cerebral ischemia-reperfusion injury.Our studies indicate that CLO flavonoids can be taken as a natural antioxidant and bacteriostastic substance in food and pharmaceutical industry.The molecular mechanisms of CLO could be at least partially attributed to the antioxidant properties and subsequently inhibiting activation of casepase-3.All experimental procedures and protocols were approved on May 16,2016 by the Experimental Animal Ethics Committee of Xinjiang Medical University of China(approval No.IACUC20160516-57).

A new cerebroside and its anti-proliferation effect on VSMCs from the radix of Cyperus rotundus L.

A new cerebroside,1-O-(β-D-glucopyranosyloxy)-(2S,3R,4E,8Z)-2-[(2′R)-2’-hydroxylignoceranoylamino]-4,8-tetradecene-3- diol was isolated from the 60%EtOH extract of traditional Chinese medical plant Cyperus rotundus L.Its structure was determined on the basis of spectroscopic data.This new compound showed anti-proliferation effect on vascular smooth muscle cells(VSMCs).

Anti-onchocerca Metabolites from Cyperus articulatus:Isolation,In Vitro Activity and In Silico‘Drug-Likeness’

The aims of this investigation were to isolate active ingredients from the roots/rhizomes of Cyperus articulatus used as herbal medicine in Cameroon for the treatment of human onchocerciasis and to assess the efficacy of the metabolites on the Onchocerca worm.The antifilarial activity was evaluated in vitro on microfilariae(Mfs)and adult worms of the bovine derived Onchocerca ochengi,a close relative of Onchocerca volvulus.Cytotoxicity was assessed in vitro on monkey kidney epithelial cells.The structures of the active compounds were determined using spectroscopic methods and their drug-likeness evaluated using Lipinski parameters.Two secondary metabolites,AMJ1[containing mustakone(1)as the major component]and linoleic acid or(9Z,12Z)-octadeca-9,12-dienoic acid(2)were isolated.Both compounds were found to kill both the microfilariae and adult worms of O.ochengi in a dose dependent manner.The IC50s for AMJ1 were 15.7 lg/mL for Mfs,17.4 lg/mL for adult males and 21.9 lg/mL for adult female worms while for linoleic acid the values were,15.7 lg/mL for Mfs,31.0 lg/mL for adult males and 44.2 lg/mL for adult females.The present report provides the first ever evidence of the anti-Onchocerca efficacy of AMJ1 and linoleic acid.Thus,these secondary metabolites may provide a lead for design and development of new antifilarial agents.

Biological Characteristies of Methane Emission of Oryzasativa，Panicumcrus－galliand Cyperusdif for misGrown on PaddySoil

Biological characteristics of methane emission were compared among Oryza sativa, Panicum crus-galli andCyperus difformis grown on paddy soil. The order of the amounts of methane emitted was P. crus-galli > O. sativa >C. difformis, with the former two 11 and 8 times as much as that of the latter, respectively. And it was just opposite tothat of the methane-forming activities of roots of the three plants. The diurnal changes of methane emission of thethree plants were relatively consistent with valleys during 11:00-14:00 and midnight and peaks during 8:00-11: 00,14:00- 20:00 and about 5:00 early morning. The methanogenic activites in rhizospheric soils were higher than those innonrhizospheric soils with P. crus-galli and O. sativa, but not with C. difformis. The pathways of methane release ofP. crus-galli and O . sativa were probably through the top gaps near the junctions of nodal plate and leaf sheath, how-ever in C. difformistopgaps from which methane could escape into atmosphere were not found.

Bioefficacy of crude extract of Cyperus aromaticus(Family:Cyperaceae)cultured cells,against Aedes aegypti and Aedes albopictus mosquitoes

Objective:To evaluate the growth inhibition activity of the crude extract of Cyperus aromaticus(C.aromaticus)cultured cells against the 3rd instar larvae of Aedes aegypti(Linn.)and Aedes albopictus Skuse(Ae.albopictus)under laboratory conditions,and determine the sublethal effects(EI_(50))of the crude extract of C.aromaticus cultured cells on some biological and morphological parameters of both Aedes mosquito species during two generations as well.Methods:The cell suspension cultures of C.aromaticus were activated from five callus lines(P4,Pa,Z1,Z6 and Ml)derived from the root explants of in vitro plantlets.The cultured cells were extracted in chloroform and used as plant material for the present study.For detection of juvenile hormone III.the crude extracts were analyzed by HPLC.Then the crude extracts of the three C.aromaticus cultured cell lines which contained varied amounts of juvenile hormone III[high level(P4 cell line),medium level(Z1 cell line)and low level(Ml cell line)]were tested against Aedes mosquito species.Laboratory evaluation was performed against late third instar larvae of the Vector Control Research Unit strains of Ae.aegypti and Ae.albopictus using the standard WHO method.The effects of EI_(50)of the C.aromaticus cultured P4 cells on fecundity,fertility,growth period,sex ratio,adult size and longevity of Aedes mosquitoes were assessed.Results:Bioassay tests presented the remarkable growth inhibition activity of the crude extracts of C.aromaticus cultured cells against the two Aedes mosquitoes.Between the two mosquito species,Ae.albopictus was more susceptible to the crude extracts with lower EI_(50)values.EI_(50)of the crude extract of C.aromaticus cultured cells(P4)increased the sterility indices in the parental generation females in both Aedes mosquito species.A significant delay in the pupal formation and adult emergence were observed in the parental generation of the both mosquito species.The sex ratio of the adult population either parental or F1 generation of the Aedes mosquito species was not significantly affected by the EI_(50)dosage of the crude extract of C.aromaticus cultured P4 cells.A significant decrease in the wing length of the treated adult(female and male)of Aedes aegypti as well as the treated female of Ae.albopictus were observed.Longevity of the adult female of the parental generation of both Aedes mosquitoes as well as females of F1 generation of Ae.albopictus were significantly decreased.Conclusions:The present study revealed the potential of the crude extract of C.aromaticus cultured cells in controlling vector mosquito populations in the effort to reduce the transmission of vector borne diseases.

Phytoremediation potential of Cyperus rotundus for diesel-contaminated wetland

Oil spills may considerably damage sensitive coastal wetlands. The phytoremediation potential and restoration of a dominant coastal marsh plant, Cyperus rotundus, for diesel pollutant and its phytoremediation effectiveness were investigated in this open-air pot experiment. Cyperus rotundus was transplanted into soil contaminated with diesel at concentrations of 1 000, 5 000, 10 000, 15 000, 20 000 mg/kg. In order to better elucidate the biochemical and physiological responses to diesel pollutants, activity of the antioxidant enzymes peroxidase （POD）, catalase （CAT） and ascorbic acid oxidase （AAO） were determined in the plant tissue after 50 d treatment at the levels mentioned above. The results showed that CAT and AAO of stem and leaf exhibited peak enzyme activities on 15 000 mg/kg soil and 10 000 mg/kg soil respectively, and declined at higher concentrations. Additionally, the increment of biomass and the content of soluble protein, as well as chlorophyll content were affected by diesel. The highest restoration effectiveness appeared at the level of 5 000 mg/kg. Collectively, Cyperus rotundus is a potential plant which can be used for restoring the diesel-contaminated soil.

Growth and Development of <i>Cyperus papyrus</i>in a Tropical Wetland

Relative growth rate (RGR) is an important parameter in plant growth models. However, no field measurements of RGR have been made in Cyperus papyrus (papyrus) wetlands. In this study, the growth dynamics of aerial shoots were investigated in a tropical papyrus wetland. The aim was to estimate temporal changes in the growth rates, and also establish the effect of water level and temperature change on total culm number, culm recruitment and senescence. Dry weights of shoots during their life cycle were determined using a non-destructive method after establishment of relationship between culm diameter and dry weight. Measurements were made over period of seven months. During the course of the measurements, culm density significantly increased from 16.1 to 35.9 culms.m-2. There were significant changes in both culm recruitment and senescence. Maximum RGR of developing culms was 1.04 g g-1 d-1. Using a culm density of 27 per m-2, productivity range was 16.74 to 37.37 g m-2 d-1. There was an inverse and significant relationship between rate of change in leaf weight ratio (LWR) and RGR of the culms. In conclusion, RGR of the aerial shoot development was controlled by rate of change in LWR from 41 to 156 days of growth. There was a strong and negative influence of water level fluctuation on total culm density.

Design and optimization of an airflow-vibration sieving device for the effective cleaning of cyperus esculentus L.harvesting mixture

The threshing mixture of Cyperus esculentus(Tiger nut)planted in sandy areas is complex during harvesting,and there are problems of high impurity rate and high cleaning loss rate of the seeds.In this paper,the threshing mixture of Cyperus esculentus is taken as the research object,and the suspension speed of each component is measured to design an“airflow+vibration”sieving device.Use the vector polygon method to explore the law of motion of the vibrating sieve,establish the force model of the seeds on the sieve surface,and analyze the conditions for the seeds to penetrate the sieve.According to the principle of seeds penetrating the sieve and long stalks not penetrating the sieve,the geometric model of sieve blades opening degree adjustment mechanism is constructed.Study of the conditions under which long stalks can be thrown out of the machine.The experiment bench of the cleaning device was built,and the evaluation indexes were the rate of seed impurity and the rate of cleaning loss of the device,and the crank speed,sieve blades opening degree and fan speed were used as the experiment factors to study the influence law of each influencing factor on the evaluation index through single-factor experiment.Using response surface methodology to find the optimal combination of working parameters of the cleaning device.To verify the device’s application on the combine harvester to improve the effectiveness of the cleaning operation of the Cyperus esculentus combine harvester.

Hypolipidemic activity of a hydroalcoholic extract of Cyperus scariosus Linn. root in guinea pigs fed with a high cholesterol diet

Lipid-lowering and antioxidant activities of a hydroalcoholic extract of Cyperus scariosus Linn. root(HCS) were evaluated in guinea pigs fed with a high cholesterol diet. Serum lipid profile(total cholesterol, triglycerides, LDL-C, VLDL-C, and HDL-C), atherogenic indices and serum enzymes(ALT, AST, ALP, LDH, and CK-MB) were performed in each group at 0 days and at the end of 60 days. Histological study of liver and kidney was done in groups 1, 2, 5, 6 and 7. The total phenolic and flavonoid content in HCS and its antioxidant activity were evaluated by the DPPH assay. Both doses of HCS decreased serum lipid profile and atherogenic indices(P < 0.05). HCS has lipid lowering, immunosuppressive and antioxidant properties, and mays have value in atherosclerosis prevention. The higher dose of HCS also reduced serum AST, ALP, and LDH levels and rosuvastatin increased AST and ALP levels(P < 0.05). Histology of the liver showed decreased lipid accumulation and improvement in hepatocytes in HCStreated animals. The antioxidant activity of HCS may be responsible for its lipid lowering and cytoprotective action. HCS had significant lipid lowering and antioxidant activity, which; may be due to the phenolic compounds. HCS may be a safe and cost effective alternative to current statin therapy for patients with dyslipidaemia.

Evaluation of antibacterial effect of Cyperus species on typical food-borne pathogens

Objective: To evaluate the antibacterial effect of Cyperus species as an important medicine plant in the study area. Methods: The agar disk diffusion method was used to study the antibacterial activity of Cyperus extracts against 2 Gram-positive and 4 Gram-negative bacteria at concentration 400 and 600 mg/mL of methanol and the aqueous extract. Then minimum inhibitory concentrations and minimum bactericidal concentrations were determined by micro-dilution method. Results: The results showed that the methanol extract of longus species presented the highest zone of inhibition against tested pathogens (15 mm inhibition zone). Other plants did not show significant inhibition zone. The methanol extracts of the plant against Pseudomonas aeruginosa (PTTC 1707) strains showed the best activities, with the lowest minimal inhibitory concentration of 3.125 mg/mL and minimum bactericidal concentration was 166.50 and 83.25 mg/mL, respectively for Staphylococcus aureus (PTTC 1431) and Escherichia coli (PTTC 1399). Conclusions: The results showed that the methanol extract of the herb has antibacterial activity and therefore it could be used as a natural preservative ingredient in food and/or pharmaceutical industries.

Soda pulping of umbrella palm grass (cyperus flabettiformic)

Chemical,morphological and anatomical characteristics of Cyperus flabettiformic were evaluated.It is characterized with lowα-cellulose(32.2%)and moderate lignin(24.0%)content.Fiber length of C.flabettiformic was shorter(0.94mm)but slender ratio was extremely high(166).Anatomically,this grass is constituted by homogeneous parenchyma cells and the vascular bundles(11.8%).Delignification of C.flabettiformic was carried out by conventional soda pulping under varying alkali charge,time and liquor to material ratio at the boiling temperature.Total pulp yield was 55.0%with kappa number 15.5 at the cooking conditions of 12%alkali charge,2 h of cooking and liquor to material ratio 10:1.Multivariate data analysis was used to evaluate the influence of alkali charge,cooking time and liquor ratio on pulp yield and kappa number.Alkali charge had a significant effect on pulp yield and kappa number.PLSR model showed better prediction efficiencies for pulp yield and PCR model performed better prediction for kappa number.Initial drainage resistance and papermaking properties of C.flabettiformic pulp were higher than other nonwood.

INHIBITORY EFFECT OF THE CONSTITUENTS FROM THE RHIZOMES OF CYPERUS ROTUNDUS ON TRPV1 ION CHANNEL

Cyperus rotundus(Cyperaceae)is used as an analgesic and sedative in oriental medicine,and has been reported to exhibit anti-nociceptive and anti-inflammatory effects.On the other hand,transient receptor potential vanilloid channel 1(TRPV1),the so-called capsaicin receptor,is a nonselective cation channel that senses various noxious chemical and thermal stimuli.However,it has recently

不同除草剂对棉田恶性杂草香附子的防除效果及安全性分析

为筛选出棉田防除香附子(Cyperus rotundus L.)的除草剂,选用5种除草剂,采用大田试验,对比分析了其对棉田香附子的防治效果及对棉花生长的安全性。结果表明,药后14 d,75%氯吡嘧磺隆水分散粒剂(WG)和10%吡嘧磺隆可湿性粉剂(WP)对香附子的株防效分别为88.68%和87.71%,极显著高于其他药剂处理;药后21 d,75%氯吡嘧磺隆WG和10%吡嘧磺隆WP对香附子的株防效分别为78.70%和76.04%,极显著高于其他药剂处理;药后28 d,75%氯吡嘧磺隆WG对香附子的株防效和鲜重防效分别为82.37%和91.82%,极显著高于其他药剂处理;安全性分析显示,5种除草剂均对棉花生长安全。

几种湿地植物对重金属镉胁迫的生理生化响应

通过水培试验研究了不同质最浓度的重金属镉（0、20、30、40、50、60mg·L^-1）胁迫对水牛美人蕉（Canna glauca）、红蛋（Eehinodorus osiris）、风车草（Cyperus alternifolius）、彩叶草（Coleus blumeibenth）等湿地植物体内丙二醛、脯氨酸、镉的含量以及细胞膜的透性变化的影响，探讨了镉胁迫下不同湿地植物对镉的生理生化响应和耐受能力，为应用人工湿地处理含镉废水提供依据。研究结果表明，在镉胁迫下4种供试植物叶片的丙二醛含量和膜透性增加，并且试验条件下，培养液中镉质量浓度越高植物叶片中丙二醛细胞膜透性也越高；植物叶片中脯氨酸质量分数变化则有所不同，培养液中镉质量浓度处于0-40mg·L^-1时，脯氨酸质量分数随着镉质量浓度增加而增加，镉质量浓度高于40mg·L^-1，脯氨酸质量分数随着镉质量浓度的增加而降低。不同湿地植物对镉胁迫响应也显著不同，丙二醛含量、脯氨酸质量分数和细胞膜透性大小为：彩叶草〉风车草〉红蛋〉美人蕉。由此可见，4种供试植物耐受镉害的能力依次为：美人蕉〉红蛋〉风车草〉彩叶草。美人蕉和红蛋在含镉废水人工湿地生态工程修复中具有很好的应用前景。

异型莎草对不同除草剂的敏感性研究

采用盆栽法茎叶处理方式分别测定了湖南省4个地区的水田异型莎草(Cyperus difformis L.)对灭草松、二甲四氯、吡嘧磺隆、氯吡嘧磺隆、五氟磺草胺5种除草剂的敏感性。结果表明,各异型莎草种群对灭草松和二甲四氯均敏感,鲜重抑制率达90%以上;种群H1、H4对氯吡嘧磺隆不敏感,鲜重抑制率最高达32.12%;种群H1、H3、H4对吡嘧磺隆产生抗性,其ED50分别为6 397.17、194.18、198.06 g(a.i.)/hm2,且这3个种群对五氟磺草胺产生交互抗性,但种群H2对吡嘧磺隆和五氟磺草胺均敏感。