通过野外调查和温室营养液砂培试验，发现并鉴定出钻叶紫菀（Aster subulatus Michx.）是一种新的镉（Cd）超积累植物。调查结果发现，钻叶紫菀对土壤中高含量的Cd有很强的忍耐、吸收和积累能力，其地上部茎、叶Cd含量分别为90.0—150.7mg/kg和119.8—172.6mg/kg,平均值分别为132.8mg/kg和139.2mg/kg。砂基营养液培养试验证明，钻叶紫菀对生长介质中的Cd有很强的忍耐能力，当生长介质中Cd浓度高达150mg/L时，植株仍生长正常，其株高与对照相比无显著差异；地上部Cd含量及其积累量均随生长介质中Cd浓度的增加而增加，当生长介质中Cd浓度为120mg/L时，地上部茎Cd含量和积累量达到最高值，分别为5672.50mg/kg、4.93mg/株。结果表明，钻叶紫菀是一种新的Cd超积累植物，为今后探明植物超积累Cd的机理和Cd污染土壤的植物修复提供一种新的种质资源。

甘蔗在运输和贮存期间极易受病原菌侵染,发生变质并产生毒素,其中甘蔗受梨孢假壳感染及产生3-硝基丙酸(3-NPA)毒素是引起食用变质甘蔗中毒的主要原因.文章通过综述甘蔗霉变病原菌梨孢假壳的鉴定、产毒条件、环境影响因素及其3-NPA毒素合成机理、检测方法等研究进展,发现目前尚缺乏对甘蔗霉变病原菌梨孢假壳的全面、系统认识,也未对其产毒能力、产毒机理及毒性快速监测方法等提出明确要求和出台相关规定,关于甘蔗采后霉变的防控技术也鲜见报道.因此,今后应在以下几方面开展相关研究:(1)系统开展甘蔗梨孢假壳产毒能力评价、菌株分类及快速鉴定方法等研究,对高毒菌株所属区域的甘蔗消费市场进行重点监控,为疑似感染高毒菌株的甘蔗预警提供科学依据和技术支撑;(2)在侵染甘蔗条件下,深入研究环境因素对梨孢假壳毒素3-NPA产生和积累规律的影响;(3)探究毒素合成途径及分子调控机理,阐明梨孢假壳毒素3-NPA的代谢过程,解析生物合成3-NPA的系统理论知识;(4)利用分子生物学手段开展3-NPA检测研究,提高检测方法的准确性、灵敏度等;(5)通过生物防控方法高效防控甘蔗中梨孢假壳感染及其毒素3-NPA的合成,研制筛选出高效、安全、适用的甘蔗防霉变药剂.

Sugarcane (Saccharum officinarum L.) may be infected with Apiospora, which can produce the toxin 3-nitropropionic acid (3-NPA) during improper transportation and storage. The consumption of sugarcane that contains 3-NPA can lead to food poisoning. Therefore, this study sought to explore a novel biocontrol agent to prevent and control Apiospora mold. Bacteria were isolated from the soil of healthy sugarcane and identified as Bacillus velezensis T9 through colony morphological, physiological and biochemical characterization and molecular identification. The inhibitory effect of B. velezensis T9 on Apiospora mold on sugarcane was analyzed. Assays of the cell suspension of strain T9 and its cell-free supernatant showed that T9 had significant in vitro antifungal activities against Apiospora arundinis and thus, would be a likely antagonist. Scanning electron microscopy and transmission electron microscopy showed that treatment with T9 significantly distorted the A. arundinis mycelia, perforated the membrane, contracted the vesicles, and decomposed most organelles into irregular fragments. A re-isolation experiment demonstrates the ability of T9 to colonize the sugarcane stems and survive in them. This strain can produce volatile organic compounds (VOCs) that are remarkably strong inhibitors, and it can also form biofilms. Additionally, the cell-free supernatant significantly reduced the ability of A. arundinis to produce 3-NPA and completely inhibited its production at 10%. Therefore, strain T9 is effective at controlling A. arundinis and has the potential for further development as a fungal prevention agent for agricultural products.

Aims This study aimed to investigate the inhibitory effect of tannic acid (TA) on the growth of Apiospora arundinis and 3-Nitropropionic acid (3-NPA) production.Methods and results To investigate the antifungal mechanism, the effects of TA on the hypha growth, electrical conductivity, hypha morphology, defense-related enzymes, and 3-NPA production of A. arundinis were studied. TA concentrations of 640 and 1280 mu g ml-1 exhibited strong antifungal activity against A. arundinis. The results of scanning electron microscopy and transmission electron microscopy showed that the hypha of the A. arundinis was severely deformed after TA treatment, and the cell membrane was blurred and thin, vacuoles were obviously shrunken and smaller, and most of the organelles were decomposed into irregular fragments. The increased electrical conductivity and malondialdehyde content indicated that TA caused peroxidation of unsaturated fatty acids and damaged the structure of the cell membrane. The decrease of intracellular ATPase and succinate dehydrogenase content indicated that TA damaged the function of mitochondria, and participated in the inhibition of respiratory metabolism. In addition, TA significantly reduced 3-NPA production and completely inhibited 3-NPA production at 640 and 1280 mu g ml-1.Conclusion TA effectively inhibited both growth of A. arundinis in vitro and 3-NPA production.

In this study, a new biosorbent was prepared from sugarcane bagasse and polyethylenimine (MSCP).The effects of preparation parameters, including the polyethylenimine (PEI) concentration, the glutaraldehyde concentration, the reaction temperature, and ball milling time on the adsorption property of MSCP were studied.The optimum preparation conditions were as follows: the PEI concentration was 20%, the glutaraldehyde concentration was 2.0%, the reaction temperature was 318.15 K, and the ball milling time was 20 min.Under the optimum preparation conditions, the removal efficiency of Cu 2+ by MSCP was reached 93.3%.The physical and chemical properties of MSCP were determined by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and elemental analysis.The SEM micrographs revealed that surface morphology of MSCP was rough, with many irregular folds and small particles.The FTIR and elemental analysis results indicated PEI was successfully grafted to the surface of sugarcane bagasse cellulose (SC) with glutaraldehyde as a bridge and the adsorption mechanism of heavy metals by MSCP can be regarded as the complexation between heavy metals and -NH 2 groups of MSCP.Langmuir model showed the best fitting to the isotherm equilibrium data, the maximum adsorption capacities for Cu 2+ , Pb 2+ and Zn 2+ were 114.02, 165.56 and 95.79 mg/g, respectively.The adsorption experimental data were fitted well by pseudo-second-order.In multi-solute system, the competitive adsorption ability of heavy metals by MSCP followed the order of Pb 2+ > Cu 2+ > Zn 2+ .

HomePlant DiseaseVol. 106, No. 3First Report of Apiospora Mold on Sugarcane in China Caused by Apiospora arundinis (Arthrinium arundinis) PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Apiospora Mold on Sugarcane in China Caused by Apiospora arundinis (Arthrinium arundinis)Jie Liao, Wenyan Jiang, Xiaojian Wu, Jie He, Huiling Li, Tianshun Wang, Liang Cheng, Wei Chen, and Leixing MoJie Liaohttps://orcid.org/0000-0001-5978-2252Agro-Products Quality Safety and Testing Technology Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, ChinaSearch for more papers by this author, Wenyan JiangAgro-Products Quality Safety and Testing Technology Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, ChinaSearch for more papers by this author, Xiaojian WuMicrobiology Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, ChinaSearch for more papers by this author, Jie Hehttps://orcid.org/0000-0002-2734-1644Agro-Products Quality Safety and Testing Technology Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, ChinaSearch for more papers by this author, Huiling LiAgro-Products Quality Safety and Testing Technology Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, ChinaSearch for more papers by this author, Tianshun WangAgro-Products Quality Safety and Testing Technology Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, ChinaSearch for more papers by this author, Liang ChengAgro-Products Quality Safety and Testing Technology Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, ChinaSearch for more papers by this author, Wei ChenAgro-Products Quality Safety and Testing Technology Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, ChinaSearch for more papers by this author, and Leixing Mo†Corresponding author: L. Mo; E-mail Address: molx03@163.comAgro-Products Quality Safety and Testing Technology Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, ChinaSearch for more papers by this author AffiliationsAuthors and Affiliations Jie Liao1 Wenyan Jiang1 Xiaojian Wu2 Jie He1 Huiling Li1 Tianshun Wang1 Liang Cheng1 Wei Chen1 Leixing Mo1 † 1Agro-Products Quality Safety and Testing Technology Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China 2Microbiology Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China Published Online:16 Feb 2022https://doi.org/10.1094/PDIS-02-21-0386-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleSugarcane (Saccharum officinarum L. cv. Badila) is a chewing cane cultivar in southern China. Since the first case of poisoning caused by the consumption of moldy sugarcane was confirmed in northern China in 1972, cases have occurred almost every year. It has been confirmed that Arthrinium is the pathogen that primarily occurs during improper postharvest storage (Liu et al. 1984). In 2019, 10 moldy sugarcane stems (cv. Badila) were collected from Tang County, Baoding City, Hebei Province, China. The sugarcane flesh turned dark and was grayish-white, red, or reddish-brown. Some of them smelled musty. Symptomatic stems were surface disinfected using 75% ethanol and peeled aseptically. Small sections (3 mm3) were placed on potato dextrose agar amended with 0.01% chloramphenicol and incubated at 26 ± 2°C. Six fungal isolates were obtained from three sugarcane stems, a positive sample rate of 30%, and identified as the same fungus on the basis of morphological features owing to their formation of flat colonies that were initially white and later turned grayish white with moderate amounts of aerial mycelia. The mycelia consisted of smooth, hyaline, branched, and septate hyphae. The conidiophores were hyaline or pale brown and produced conidiogenous cells. The conidiogenous cells were pale brown, smooth, ampulliform, and 5.5 to 11.2 μm long (n = 50). The conidia were brown, smooth, ellipsoidal to spherical, spherical in surface view, 4.5 to 7.4 μm in diameter, and 3.3 to 4.4 μm wide with a pale equatorial slit (n = 50). The morphological characteristics of the one representative isolate, named LX1918, were identical to those of Arthrinium arundinis (Corda) Dyko & B. Sutton (Apiospora arundinis [Corda] Pintos & P. Alvarado) (Crous and Groenewald 2013; Pintos and Alvarado 2021). Genomic DNA was extracted from the mycelia to further identify the isolate. The internal transcribed spacer region (ITS rDNA), the translation elongation factor 1-alpha gene (TEF1), and the β-tubulin gene (TUB2) were amplified using the primers ITS1/ITS4, EF1-728F/EF-2, and T1/Bt2b (O’Donnell et al. 1997, 1998; White et al. 1990), respectively. BLASTn analysis of the ITS (556 bp, GenBank accession no. MW534386), TEF1 (434 bp, MW584370), and TUB2 (775 bp, MZ090019) sequences of isolate LX1918 showed that they were 99.43, 99.52, and 99.74% similar to the published sequences of isolate CBS 106.12 (KF144883, KF145015, and KF144973), respectively. To confirm Koch’s postulates, pathogenicity tests were conducted in triplicate by inoculating the aseptic wounds with a conidial suspension (105/ml) of the isolate in healthy sugarcane stems. The controls were inoculated with sterile water. The sugarcane stems were incubated at 26 ± 2°C and 86% relative humidity in the dark. Obvious moldy symptoms appeared several days after the sugarcane stems had been inoculated. The sugarcane flesh turned reddish brown. In contrast, the control stems were asymptomatic. Ap. arundinis (Ar. arundinis) was reisolated from the inoculated and moldy sugarcane. In addition, 3-nitropropionic acid could be detected using HPLC-MS after the fungus had been cultured on potato yeast sucrose agar for 14 days. Previous studies had confirmed that 3-nitropropionic acid produced by Ar. sacchari, Ar. saccharicola, and Ar. phaeospermum is the causal agent of poisoning caused by the consumption of moldy sugarcane (Hu et al. 1986; Liu et al. 1988). To our knowledge, this is the first report of Ap. arundinis (Ar. arundinis) as the causal agent of infected sugarcane and its production of 3-nitropropionic acid, which is toxic to humans. Therefore, the confirmation that Ap. arundinis (Ar. arundinis) infects sugarcane will expand our understanding of this pathogen and provide fundamental knowledge about the control of Apiospora mold to decrease the incidents of 3-nitropropionic acid poisoning.The author(s) declare no conflict of interest.References:Crous, P. W., and Groenewald, J. Z. 2013. IMA Fungus 4:133. https://doi.org/10.5598/imafungus.2013.04.01.13 Crossref, ISI, Google ScholarHu, W. J., et al. 1986. Chin. J. Preventive Med. 20:321. Google ScholarLiu, X. J., et al. 1984. Hygiene Res. 13:28. Google ScholarLiu, X. J., et al. 1988. Acta Mycol. Sinica 7:221. Google ScholarO’Donnell, K., et al. 1997. Mol. Phylogenet. Evol. 7:103. https://doi.org/10.1006/mpev.1996.0376 Crossref, ISI, Google ScholarO’Donnell, K., et al. 1998. Proc. Natl. Acad. Sci. U.S.A. 95:2044. https://doi.org/10.1073/pnas.95.5.2044 Crossref, ISI, Google ScholarPintos, A., and Alvarado, P. 2021. Fungal Syst. Evol. 7:197. https://doi.org/10.3114/fuse.2021.07.10 Crossref, Google ScholarWhite, T. J., et al. 1990. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA. Google ScholarFunding: This work was supported by the National Natural Science Foundation of China (31860014).The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 106, No. 3 March 2022SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Downloaded 820 times Article History Issue Date: 30 Mar 2022Published: 16 Feb 2022First Look: 21 Sep 2021Accepted: 15 Sep 2021 Page: 1058 Information© 2022 The American Phytopathological SocietyFundingNational Natural Science Foundation of ChinaGrant/Award Number: 31860014KeywordsArthrinium arundinisApiospora arundinismoldy sugarcane3-nitropropionic acidThe author(s) declare no conflict of interest.PDF download

通过批量吸附实验对单宁-聚乙烯亚胺（TAP）吸附Cr（Ⅵ）的性能进行研究。结果表明,TAP对Cr（Ⅵ）的吸附受p H影响显著,当温度为60℃、溶液初始质量浓度为200 mg/L、p H为3时,其吸附量为73.96 mg/g。TAP对Cr（Ⅵ）的吸附行为符合Langmuir等温吸附模型和准二级动力学模型,吸附过程为吸热反应。利用SEM、FT-IR和XPS对吸附前后的TAP进行表征,结果表明,该吸附剂对Cr（Ⅵ）的吸附机制主要以化学还原与螯合作用为主,吸附剂上的—OH和—NH2基团参与了反应。

[目的]探究螯合剂[乙二胺二琥珀酸(EDDS)、氨三乙酸(NTA)和乙二醇二乙醚二胺四乙酸(EGTA)]对青葙镉(Cd)、铅(Pb)、锌(Zn)和铜(Cu)吸收累积的影响,为螯合剂和青葙在环境修复中的应用提供数据支撑.[方法]采用大棚内盆栽种植青葙试验方法,以不添加螯合剂作对照(CK),研究螯合剂EDDS(1.0、2.0和3.0 mmol/kg)、NTA(1.0、2.0和3.0 mmol/kg)和EGTA(1.0、2.0和3.0 mmol/kg)作用下青葙对土壤Cd、Pb、Zn和Cu的吸收与转运.[结果]与CK相比,1.0和2.0 mmol/kg EDDS、1.0～3.0 mmol/kg NTA、1.0和2.0 mmol/kg EGTA能显著促进青葙生长(P<0.05,下同),其中1.0 mmol/kg EGTA促进效果最大,其干重较CK增加37.5％.1.0和2.0 mmol/kg EDDS、2.0和3.0 mmol/kg NTA、1.0和2.0 mmol/kg EGTA能显著促进青葙对Cd的吸收累积,且2.0 mmol/kg EGTA作用下,青葙中Cd的生物富集系数和转运系数提升最大,分别是CK的1.55和1.61倍;2.0和3.0 mmol/kg EDDS、1.0～3.0 mmol/kg NTA及1.0～3.0 mmol/kg EGTA均能显著促进青葙对Pb的吸收累积,且Pb在青葙中的生物富集系数和转运系数较CK均有明显提升,以3.0 mmol/kg EGTA处理的青葙地上部富集系数和转移系数最大,分别是CK的1.63和1.47倍;1.0和2.0 mmol/kg EDDS、2.0 mmol/kg EGTA能显著促进青葙对Zn的吸收累积,以1.0 mmol/kg EDDS处理的富集系数最大,是CK的1.18倍,2.0 mmol/kg NTA处理的转移系数最大,是CK的1.22倍;1.0～3.0 mmol/kg EDDS、1.0～3.0 mmol/kg NTA和1.0～3.0 mmol/kg EGTA均能显著促进青葙对Cu的吸收累积,以2.0 mmol/kg EDDS处理的青葙地上部富集系数最大,是CK的2.07倍,3.0 mmol/kg EGTA处理的青葙地上部转移系数最大,是CK的2.52倍.[结论]在本研究螯合剂施用剂量范围内,除3.0 mmol/kg EGTA减少青葙吸收累积Cd和3.0 mmol/kg EDDS、3.0 mmol/kg NTA、1.0 mmol/kg EGTA及3.0 mmol/kg EGTA减少青葙吸收累积Zn外,3种螯合剂的其余剂量均可促进青葙对Cd、Pb、Zn和Cu的吸收富集.因此,适当剂量的螯合剂作为诱导活化剂,可强化青葙吸收累积重金属Cd、Pb、Zn和Cu.

In this work, the adsorbent based on tannin (TN) and polyethylenimine (PEI) was prepared via a simple and green method (TNP). The characteristics of the TNP were determined using scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, and the results revealed that TNP was synthesized by TN and PEI, and Cu(II) was combined with the -NH or -OH groups of TNP. The effects of the n((TN)):n((PEI)), adsorbent dosage, pH, time, initial metal concentration, and temperature on the adsorption of Cu(II) were investigated in detail. The adsorption of Cu(II) by TNP was greatly affected by pH, and n((TN)):n((PEI)), = 1.5:3 was the optimum mole ratio of raw material to obtain TNP. TNP possessed excellent adsorption properties, and the maximum adsorption capacity of TNP for Cu(II) was 94.5 mg/g at 338.15 K. The adsorption process was in agreement with the Langmuir model and the pseudo-second-order model. Regeneration and reusability of TNP did not decrease significantly after four times of regeneration experiments. The order of competitive ability for the three metal ions was as follows: Pb(II) > Cu(II) > Zn(II). These experimental results suggested that TNP could effectively remove metal ions from aqueous solution. This study is of great significance for environmental protection.

采用桶栽试验的方法,以斑茅(Saccharum arundinaceum Retz.)为材料,研究不同重金属复合污染条件下斑茅的生长响应及重金属吸收、富集和迁移特征变化,为斑茅在重金属复合污染土壤中的修复应用提供理论依据.结果表明,随着复合污染土壤中重金属含量的增加,斑茅地上部鲜质量逐渐下降,最多较对照(不添加重金属)下降26.71％;斑茅根、茎、叶组织中的Cd、Zn、Pb、Cu含量也逐渐增加,其根部Cd、Zn、Pb、Cu的最大含量分别为104.4、2486.0、379.7、1457.3 mg/kg,其茎部Cd、Zn、Pb、Cu的最大含量分别为32.3、1461.7、77.6、25.3 mg/kg,其叶部Cd、Zn、Pb、Cu的最大含量分别为13.6、488.5、21.7、43.5 mg/kg;除对照外,同一处理水平Cd、Zn、Pb、Cu在斑茅中的富集系数表现为茎部Zn>Cd>Pb>Cu,叶部Cd>Zn>Cu>Pb;随着复合污染土壤中重金属含量的增加,斑茅茎部Cd、Zn、Pb、Cu的转移系数逐渐减小,而叶部Cd、Zn的转移系数逐渐增大,叶部Pb和Cu的转移系数先增大后减小.综合考虑,斑茅对Cd、Zn具有较好的吸收累积及转运能力,可作为Cd、Zn污染土壤的修复植物.

[目的]探究不同螯合剂[乙二胺二琥珀酸(EDDS)、氨三乙酸(NTA)和乙二醇二乙醚二胺四乙酸(EGTA)]对钻叶紫苑镉(Cd)、铅(Pb)、锌(Zn)和铜(Cu)等重金属吸收累积的影响,为螯合剂和钻叶紫苑在环境修复中的应用提供参考依据.[方法]采用大棚内盆栽种植钻叶紫苑试验方法,以不添加螯合剂作对照(CK),探究在3种螯合剂(EDDS、NTA和EGTA)不同浓度(1.0、2.0和3.0 mmol/kg)的作用下,钻叶紫苑中Cd、Pb、Zn和Cu的含量变化.[结果]1.0 mmol/kg NTA和1.0 mmol/kg EGTA处理能显著促进钻叶紫苑的生长(P<0.05,下同),其干重分别较CK增加21.4％和25.8％;1.0 mmol/kg EDDS及2.0和3.0 mmol/kg EGTA处理能有效促进Cd在钻叶紫苑中吸收累积,且Cd在钻叶紫苑中的富集系数和转移系数均有显著提升,以1.0 mmol/kg EDDS处理的富集系数(0.08)和3.0 mmol/kg EGTA处理的转移系数(4.06)最大;1.0 mmol/kg NTA及2.0和3.0 mmol/kg EGTA处理能有效促进钻叶紫苑对Pb的吸收累积,且Pb在钻叶紫苑中的富集系数和转移系数较CK均有显著提升,以3.0 mmol/kg EGTA处理的富集系数和转移系数最大,分别为CK的1.48和1.35倍;2.0和3.0 mmol/kg EDDS、1.0和2.0 mmol/kg NTA及3.0 mmol/kg EGTA处理能有效促进钻叶紫苑对Zn的吸收累积,且Zn在钻叶紫苑中的富集系数和转移系数较CK均有显著提升,以2.0 mmol/kg EDDS处理的富集系数最大,为CK的1.37倍,2.0 mmol/kg NTA处理的转移系数最大,为CK的1.49倍;3.0 mmol/kg EDDS、3.0 mmol/kg NTA和1.0～3.0 mmol/kg EGTA处理能有效促进钻叶紫苑对Cu的吸收累积,以2.0和3.0 mmol/kg EGTA处理的富集系数(均为0.66)和3.0 mmol/kg EDDS处理的转移系数(1.46)最大.[结论]3种螯合剂在合适剂量条件下均可促进钻叶紫苑对Cd、Pb、Zn和Cu的富集与转运(除EDDS对钻叶紫苑吸收富集Pb的影响作用不明显外),因此,以适宜浓度的螯合剂EDDS、NTA和EGTA作为诱导活化剂,可强化钻叶紫苑吸收富集重金属Cd、Pb、Zn和Cu.

[目的]探究螯合剂[乙二醇二乙醚二胺四乙酸(EGTA)、氨三乙酸(NTA)、乙二胺二琥珀酸(EDDS)]对鬼针草镉(Cd)、锌(Zn)、铅(Pb)和铜(Cu)吸收累积的影响,筛选出能够强化鬼针草重金属吸收能力的螯合剂.[方法]采用室内盆栽试验方法,在采自矿区的Cd、Zn、Pb和Cu复合污染的土壤上种植鬼针草,研究螯合剂EGTA、NTA和EDDS作用下鬼针草对污染土壤中Cd、Zn、Pb和Cu的吸收与转运.[结果]3种螯合剂均能促进鬼针草的生长,其促进效果为:EDDS＞ EGTA＞ NTA.从根茎叶组织单位含量看,EGTA、NTA和EDDS均能促进Zn在鬼针草茎部的吸收,促进Pb在鬼针草根部的吸收以及Cu在鬼针草根茎叶部的吸收.从植株吸收累积总量来看,EGTA促进鬼针草Zn吸收累积效果最好,EDDS促进鬼针草Pb、Cu吸收累积效果最好,3种螯合剂对鬼针草吸收Cd的影响效果不佳.EGTA作用下鬼针草叶部及茎部对Cu的富集系数和转移系数均高于对照,说明EGTA能有效促进Cu在鬼针草体内的富集及转运.[结论]除EGTA、EDDS对鬼针草吸收Cd影响作用不显著,且NTA不仅减少了鬼针草对Cd的吸收,对鬼针草Zn吸收提升也不显著外,3种螯合剂均显著提升了鬼针草对Zn、Pb和Cu的吸收累积量.

为了解镉胁迫下甘蔗的生理生化响应,通过桶栽试验模拟甘蔗在镉胁迫下生长,探讨镉胁迫的不同浓度和不同时期对甘蔗生理生化的影响.结果 表明:镉处理对甘蔗叶绿素均有不同程度的影响,随着时间的推移叶绿素变化得更为明显;对于清除活性氧系统酶类,包括超氧化物歧化酶(SOD)和过氧化物酶(POD),相比于对照则出现了较大的波动;脯氨酸(PRO)和丙二醛(MDA)含量受镉浓度影响较小,在镉处理前期并未有明显的变化,但在处理中后期出现了明显的上升趋势;谷胱甘肽(GSH)和非蛋白巯基(NPT)含量在不同的镉浓度和处理时期都有增加的趋势,而植物络合素(PCs)则随着镉浓度的增加会出现先升高后趋于平稳的情况.甘蔗生理不仅受镉浓度处理的影响,随着时间的推移响应的镉积累也是左右甘蔗生理变化的重要因素.

The present study has been undertaken to develop a method for determination of cadmium in chewing cane by microwave digestion and graphite furnace-atomic absorption spectrometry.The chewing cane samples were digested with HNO3and H2O2solu-tions,the digested solution obtained was diluted to 100 mL,and was used to determinate cadmium under the optimum working con-dition of graphite furnace-atomic absorption spectrometry.Linear relationship between values of signal and mass concentration of cadmium was obtained in the range within 0~1.0 μg·L-1.The relative coefficient,the detection limit(S/N=3)and the recovery rate was found to be 0.9994,0.016μg·kg-1and 90.0% ~108.6%.As used as the control,the cadmium content detected in standard sample was in range of standard value.The present method was found highly sensitive,accurate precision,rapid,safe and convenient.Therefore,it could be used for the determination of cadmium content in chewing cane.

Using sand culture experiments,a common cultivating chewing cane(Badila) in Guangxi was used as material,and four silicon(Si,as Na2SiO3·9H2O)levels of 0,10,20 and 40 mg/L were designed to study the effects of different Si treatment on physiological and biochemical indexes of chewing cane seedling under cadmium(Cd,as CdCl2·2.5H2O) stress,so as to further reveal the alleviation mecha-nism of Si on the toxicity of chewing cane under Cd stress,and provide a scientific basis for the reasonable utilization of Si to alleviate the toxicity of heavy metals to plants.The results showed that the activities of SOD,CAT,MDA content,Pro content in chewing cane seedlings were increased,the chlorophyll content were reduced under Cd stress.Exogenous Si could reduce the activity of SOD in chewing cane seedlings under Cd stress,especially the concentration of 40 mg/L;exogenous Si could reduce the activities of CAT,MDA content and Pro content,especially the concentration of 10 mg/L;exogenous Si could increase the chlorophyll content in chewing cane seedlings under Cd stress especially the concentration of 20 mg/L. To sum up,exogenous Si with appropriate concentration could alleviate the damage caused by Cd stress in the chewing cane seedlings.

[Objective]The present paper aims to reveal the changes of Cd absorption and free amino acids in sugarcane under the stress of cadmium (Cd),and to provide a basis for further study of the tolerance mechanism of sugarcane on Cd stress.[Method] Cd uptake and the changes of sugarcane free amino acids were determined by amino acid analyzer and Atomic fluorescence spectrometer with different Cd concentration(0,25,50,100 mg/kg) under potted conditions.[Result] It was found that the toxic symptoms of sugarcane increased with the increasing of Cd concentration,the Cd content in sugarcane stems and sugarcane leaves increased with the increasing of Cd concentration,and showed a significant positive correlation;the content of Arg and Leu increased with the increase of Cd concentration.The amino acids such as Asp and Glu decreased as the concentration of Cd treatment was 25 mg/kg and then increased with the increasing of Cd concentration.[Conclusion] Cd content in stems and leaves of sugarcane were significantly increased and 17 kinds of free amino acids content were changed under Cd stress.

The contents of soil heavy metals,such as Cd,Pb,Cr,Cu,Zn,As and Hg,in surface soil (0~20 cm) from the main chewing cane production farmland in Guangxi Zhuang Autonomous Region,were investigated. Pollution characteristics of heavy metals in soils were observed on the basis of environmental quality secondary standard values of single factor pollution index method and comprehensive pollution index method. Potential ecological risk assessment was evaluated by using the geoaccumu-lation index (Igeo) and potential ecological risk index (RI). The results indicated that the average concentrations of Cd,Pb,Cr, Cu,Zn,As and Hg were 0.81,30.4,54.5,29.8,107.4,16.69 and 0.28 mg/kg,respectively. According to the comprehensive pollu-tion index,the pollution degree was middle degree with PN was 2.03. According to the geoaccumulation index,the pollution de-gree of Cd was middle degree with Igeo was 1.02,and Hg ranged from light to middle degree with Igeo was 0.30. The potential ecological risk index indicated that the heavy metals in the soils from research area were at the moderate ecological hazard level. The rate of contribution for Cd was the highest to potential ecological risk index. Thus,effective farmland soil manage-ment is necessary to ensure security production, control soil pollution sources,and implement standard agricultural production.

[Objective] To provide a reference for exploring the inner relationship between Cd pollution and sugarcane growth,Cd pollution and microbial properties,the effects of adding different concentrations of exogenous cadmium (Cd) on the growth of sugarcane,the number of soil microbes and the activity of soil enzymes were studied.[Method]The sugarcane plant height,stem diameter,the yield of cane,the soil microbial quantity and enzyme activity were determined by using sugarcane as material treated with different Cd concentration (0,25,50,100,250,500 mg/kg) under potted conditions.[Result] The results showed that the plant height,stem diameter and the yield of sugarcane decreased with the increase of Cd concentration in the soil,the higher the Cd concentration,the more obvious the inhibition effect.The Cd pollution changed the enzyme activity,and the activity of urease and acid phosphatase was significantly decreased with the increase of Cd concentration especially when Cd concentration reached 100 mg/kg.The sensitive order of the two soil enzymes to Cd was urease ＞ acid phosphatase.Cd pollution also changed the soil microbial quantity.Fungi,bacteria and actinomycetes significantly decreased at the Cd concentration level of 100 mg/kg.There were significant and highly significant correlations between Cd contamination concentration and Fungi,bacteria,actinomycetes,activities of urease and acid phosphatase,plant height,stem diameter as well as cane yield.[Conclusion] Under the conditions of potted planted sugarcane,the effects of exogenous Cd pollution on the growth of sugarcane,the number of soil microbes and soil enzyme activities were different.

[Objective] The experimental objective was to investigate the effects of silicon (Si) on chewing cane seedling growth and its uptake of cadmium (Cd) under Cd stress.[Method] Using sand culture experiments,a common cultivating chewing cone (Badila) in Guangxi was selected.Si (as Na2 SiO3) was applied to sand at four levels of 0,10,20 and 40 mg/L,and the effects of different Si treatments were studied on chewing cane seedling growth and its uptake of Cd under Cd stress.[Result] Fresh weight,plant height,root length of chewing cane increased with the application of Si.The heaviest fresh weight(188.48 g),the highest plant height (23.35 cm),the longest root length (23.75cm) of chewing cane were found at 20 mg/kg silicon treatment,which was increased by 78.74 ％,303.98 ％ and 85.11％ compared with the control,respectively.The results also showed that Cd concentration in root,stem,and leaf of chewing cane decreased with the application of Si.The Cd concentration in root,stem,and leaf of chewing cane were decreased by 31.69 ％-61.24 ％ at silicon treatment compared with the control T1,and it was found that Si application increased Cd transportation from root to leaf.The transport factors of Cd from root to leaf increased by 27.27 ％,72.73 ％ and 36.36 ％ at Si treatment,respectively.[Conclusion] Under Cd stress,the application of Si could promote the growth of chewing cane seedlings and reduce the Cd content in root,stem and leaf of chewing cane.To a certain extent,the application of Si alleviated the toxicity of Cd to chewing cane.

A method for simultaneous determination of imidacloprid residues and pyrimethanil residues in green vegetable (Brassica rapa var.chinensis) by using Ultra performance liquid Chromatography-Tandem Mass Spectrometry (UPLC/MS/MS) was established in this paper.The green vegetable (Brassica rapa var.chinensis) samples were extracted by acetonitrile and purified by an amino solid phase extraction (SPE) column (eluted by acetonitrile + toluene (3+ 1)),and then the gradient elution was applied in ultra performance liquid chromatography separation by using the acetonitrile-0.1％ formic acid solution as mobile phase.Samples were detected by mass spectrometry multi reaction monitoring model,using retention time and sub-ion ratio as qualitative analysis and the external standard method as quantitative analysis.Tandem mass spectrometry with electrospray ionization and multiple reaction monitoring interface in an external standard manner.The results showed that the limits of quantitation (LOQ) of imidacloprid and pyrimethanil were 3.1×10-6 mg/kg and 3.6×10-7 mg/kg respectively,and the correlation coefficients of two pesticides were more than 0.9995 in the linear range of 0.0005～0.5 mg/L.In addition,the average recoveries were 99.1％ ～105.8 ％ for imidacloprid and 99.1％ ～110.0 ％ for pyrimethanil in the range of 0.02-0.2 mg / kg,and the relative standard deviations (RSD) were less than 1.23 ％ and 1.64 ％,respectively.The proposed method had the advantages of simple operation,wide linear range,high sensitivity and reliabilty,which met the requirements for the detection of such drug residues in vegetables at home and abroad.