Genetic Variability of Astragalus sinicus L. Based on ISSR Markers

Genetic relationships among 22 accessions of Astragalus sinicus L. col ect-ed from different provinces of China were analyzed by inter-simple sequence repeat （ISSR） markers. The results showed that 10 highly reproducible ISSR fragments a-mong 40 primers were screened. Using these primers, a total of 684 ISSR frag-ments from 500 to 3 000 bp were amplified, and 59.2% of them showed polymor-phic by unweighted pair-group method with arithmetic （UPGMA） analysis. It revealed that the 22 accessions had a similarity range from 0.63 to 0.95, and existed biolog-ical diversities. Based on cluster and principal coordinate analyses, al accessions could be divided into four distinct groups.

Green synthesis,characterization,acaricidal,larvacidal,and repellent activities of copper nanoparticles of Astragalus sinicus against Hyalomma anatolicum

Objective:To green synthesize and characterize copper nanoparticles(Cu NPs)using Astragalus sinicus,as well as evaluate the acaricidal,larvacidal,and repellent activities of Cu NPs against Hyalomma anatolicum(H.anatolicum),one of the most prevalent ticks infesting cattle in Saudi Arabia.Methods:Cu NPs were green synthesized by adding the Astragalus sinicus extract to a copper sulfate solution.The acaricidal,larvicidal,and repellent activities of Cu NPs against H.anatolicum were assessed via the adult immersion test,the larval packet test,and the vertical movement behavior of tick larvae,respectively.The effects of Cu NPs on acetylcholinesterase as well as oxidative enzyme activities were examined.Results:The green synthesized Cu NPs displayed a spherical form with a size range of 15-75 nm.After exposure of adult H.anatolicum to different concentrations of Cu NPs,the viability rate of adult H.anatolicum and the mean number,weight,and hatchability of eggs were noticeably reduced,in comparison to the control group(P<0.001).In addition,the viability rate of larvae considerably declined(P<0.001)with the LC_(50)and LC_(90)values of 11.30 and 20.34μg/m L,respectively.The maximum repellent activity of Cu NPs was observed at 50,100,and 200μg/m L with complete repellent activity after 60,120,and 180 min of exposure,respectively.Cu NPs,mainly at 1/2 LC_(50)and LC_(50)concentrations,markedly suppressed the acetylcholinesterase activity of the larval stage of H.anatolicum(P<0.001).Moreover,Cu NPs,mainly at LC_(50)dose,significantly elevated malondialdehyde level while declining glutathione-S-transferase level in H.anatolicum larvae(P<0.001).Conclusions:Cu NPs show potent acaricidal,larvicidal,and repellent activities against adults and larvae of H.anatolicum.However,further studies must be performed to clarify the precise mechanisms and the efficacy of Cu NPs in practical use.

Adaptability Comparison of Chinese Milk Vetch (Astragalus sinicus) Varieties for Double-rice Cropping System in Hunan

Five Chinese milk vetch（Astragalus sinicus） varieties were selected to make a comparison in order to screen effective varieties which could suit for the double-rice cropping system of Hunan Province. The results showed that the growth period of Xiangzi 2 is shorter than that of Xiangfei 2, Xiangfei 3 and Yujiangdaye,and is similar to that of Xinyang Chinese milk vetch. The full-bloom stage of Xiangzi 2 is also similar to Xinyang variety and obviously earlier than that of the other three varieties. The fresh grass yield of Xiangzi 2 in full-bloom stage is 23 842.5kg/hm^2, which increases by 39.9% compared with Xinyang variety. Nitrogen content in the fresh grass of Xiangzi 2 is higher than that of the other four varieties. In conclusion, Xiangzi 2 is an extremely early-blossoming and early-maturing Chinese milk vetch variety with moderate fresh grass yield, high nutrient contents, stable characters and wide adaptability. So, Xiangzi 2 is suitable for planting in double-rice cropping region in Hunan Province and other same latitude regions which have similar ecological conditions.

Effects of Ploughing Astragalus sinicus at Maturity Stage on Rice Yield and Soil Properties of Paddy Field

[Objective] The effects of ploughing Astragalus sinicus at maturity stage as green manure on paddy soil properties were studied to provide references for ad- vancing the green manure production and field sustainable development. [Methods] A three-year field positioning experiment was carried out. In the first year, five differ- ent levels （0, 2.81, 5.61, 8.42, 11.23 t/hm~） of Astragalus sinicus ploughed at matu- rity stage were designed. And in the next two years, the amounts of ploughed As- tragalus sinicus at maturity stage were based on the natural growth amounts of As- tragalus sinicus at maturity stage of the former year in each plot field. The yields of Astragalus sinicus at maturity stage were estimated and ploughed directly before rice transplanting. Rice yield, soil nutrients, biological properties and water-stable aggre- gates of paddy fields were measured as well. [Results] The effective panicles and rice yields increased significantly after ploughing Astragalus sinicus at maturity stage. Meanwhile, the organic acid content in paddy field increased and the activities of soil phosphatases, invertase and catalase were higher. The soil dissolved organic carbon also increased with the increasing application of green manure. However, excess amount of green manure inhibited the soil microbial biomass carbon content. The macro aggregates and micro aggregates gathered to middle aggregates. [Conclusion] As green manure, the use of Astragalus sinicus at maturity stage could improve soil physiochemical and biological properties, improve soil fertility and increase rice yield significantly. But the ploughing amount of Astragalus sinicus at maturity stage before rice transplanting should be less than 8.42 t/hm2 （dry weight.

Vacuolar phosphate transporters account for variation in phosphate accumulation in Astragalus sinicus cultivars

Astragalus sinicus is a commonly used legume green manure that fixes atmospheric N2 and accumulates mineral nutrients and organic substances that are beneficial to soils and subsequent crops.However,little is known about genotypic variation in,and molecular mechanisms of,Pi(phosphate)uptake and storage in A.sinicus.We recorded the morphological responses of six A.sinicus cultivars from four regions of China to external Pi application and measured their Pi accumulation.We identified full-length transcripts of Pi-signaling and Pi-homeostasis regulators by sequencing and measured the expression level of these genes by qRT-PCR.The major components in Pi signaling and Pi homeostasis were largely conserved between A.sinicus and the model species rice and Arabidopsis.Different A.sinicus varieties responded differently to low-phosphorus(P)stress,and their Pi accumulation was positively correlated with the expression of vacuolar Pi influx gene(SYG1/PHO81/XPR1-MAJOR FACILITATOR SUPERFAMILY(SPX-MFS)-TYPE PROTEIN)AsSPXMFS2 and negatively correlated with the expression of the vacuolar Pi efflux gene(VACUOLAR Pi EFFLUX TRANSPORTER)AsVPE1.We identified key Pi-signaling and Pihomeostasis regulators in A.sinicus.The expression of vacuolar Pi transporter genes could be used as an index to select A.sinicus accessions with high Pi accumulation.

Identification of two novel nodule-specific genes from Astragalus sinicus L. by suppressive subtractive hybridization

To identify the genes involved in nodule formation and to increase usable molecular probes, a cDNA library of Astragalus sinicus genes specifically expressed in infected roots by Mesorhizobium huakuii 7653R is generated using a PCR-based suppressive subtractive hybridization (SSH) technique with two mRNA populations of infected and uninfected control roots. Two nodule-specific genes, AsIIC259 and AsG2511, are identified from infected roots of A. sinicus. The amino acid sequences deduced from the open reading frames (ORFs) reveal that AsIIC259 and AsG2511 encodes a polypeptide with 134 and 58 amino acids, respectively. A signal peptide sequence is predicted with high probability at the N-termini of the AsIIC259 and AsG2511. The motif searches show that the deduced polypeptide of AsIIC259 con- tains two N-glycosylation sites, a cAMP- and cGMP-dependent protein kinase phosphorylation site and a casein kinase II phosphorylation site. BLASTP searches reveal that AsIIC259 putative protein displays a low degree of similarity to a unique nodulin from Lupinus luteus nodules. No significant identity is displayed over the predicted polypeptides of AsG2511 with any published sequences. Virtual Northern blot and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) analyses indicate that the two genes are expressed exclusively in inoculated roots and that their expression is 2―4 d later than that of the leghaemoglobin (Lb) gene during nodule development.

磷钾对紫云英(Astragalus sinicas L.)生长和土壤性状的影响

为研究不同区域磷钾养分对紫云英(Astragalus sinicas L.)生长和土壤性状的影响,为紫云英的高产栽培措施提供参考,在安徽合肥和广西南宁分别设置了不同磷钾养分添加的盆栽试验,测定了紫云英产量及养分累积量,并分析了土壤理化性状、胞外酶[α-葡萄糖苷酶(AG)、β-葡萄糖苷酶(BG)、磷酸酶(PHO)、乙酰氨基葡萄糖苷酶(NAG)、亮氨酸氨基肽酶(LAP)、β-木糖苷酶(XYL)]活性对磷钾养分的响应。结果表明:与不施肥处理相比,磷钾配施显著提升了安徽合肥紫云英鲜草产量和磷积累量,提升幅度分别为37.69%和54.01%;磷钾配施及单施钾肥处理对广西南宁紫云英全钾积累量分别提高了60.66%和59.23%。磷钾养分施用对安徽合肥土壤养分含量无显著影响,在广西南宁,单施磷肥显著提升了土壤有效磷和铵态氮含量,提升幅度分别为18.86%和75.59%;单施钾肥显著提升了土壤速效钾含量;磷钾配施显著提升了土壤速效钾和全氮含量。磷钾养分对安徽合肥6种土壤胞外酶活性皆有提升效果。土壤理化性状与酶活性在不同地区对紫云英鲜草产量贡献率不同,土壤理化性状中,安徽合肥土壤铵态氮、广西南宁土壤全氮对紫云英鲜草产量贡献率最高,分别为35.57%和21.82%;在6种胞外酶活性中,安徽合肥AG活性和广西南宁LAP活性贡献率最高,分别为25.56%和38.80%。由此可见,磷钾养分显著影响紫云英生长和土壤性状,影响程度与表现受土壤基础养分和地理环境的影响。在紫云英生长期添加适宜磷钾养分,可促进紫云英增产和土壤性状的改善,且磷钾配施效果最佳。

广西地方紫云英种质资源收集及表型多样性评价

以农业农村部“第三次全国农作物种质资源普查与收集行动”为契机,开展了广西壮族自治区紫云英(Astragalus sinicus L.)种质资源的考察收集与评价鉴定。结果表明,收集到的58份地方资源主要分布在桂东北以及0~400 m的中低海拔地区。12项农艺性状表型分析显示其遗传多样性丰富;主成分分析将12个农艺性状分为3个主成分,分别为种子产量、生物产量及生育期特征,累计贡献率达72.089%;通过加权平均计算得出综合排名前10位的种质资源为GXLF20180011、GXLF2019109、GXLF2019156、GXLF2019118、GXLF2019112、GXLF2019117、GXLF20180006、GXLF2019125、GXLF2019111、GXLF2019136;排名前10位的种质资源全生育期为134~147 d,盛花期茎粗(直径)为2.83~3.66 mm,盛花期株高为41.63~54.73 cm,单株分枝数为2.83~4.19个,每分枝花序数为5.85~6.99个,总花序数为17.55~26.23个/株,结荚花序数为14.33~19.97个/株,鲜草产量为10458.15~48792.75 kg/hm^(2),干草产量为1037.36~5724.34 kg/hm^(2),种子产量为246.75~991.20 kg/hm^(2)。

紫云英长期还田对稻田土壤DOM和Cd形态影响研究

长期种植和翻压紫云英能够显著提高土壤中有机质(SOM)和水溶性有机物(DOM)的含量,影响土壤颗粒对重金属镉(Cd)的吸附行为和Cd在土壤中的形态,了解该条件下Cd在不同土层中的特征对紫云英的进一步推广种植具有重要意义。以余江区(YJ)、南昌县(NC)、丰城市(FC)3地长期种植和翻压紫云英处理(F+M)和化肥处理(F)的定位试验点为研究对象,测试了不同层次土壤中SOM、水溶性有机碳(DOC)含量、Cd总量和形态、DOM三维荧光,以期探明紫云英长期还田模式下不同土层中DOM成分的差异及其对Cd含量和形态影响。结果显示,NC和FC试验点F+M处理耕作层土壤(0-20 cm)中SOM的含量显著高于F处理,分别提高16.8%和10.5%。同一土层中土壤Cd活性呈现F+M处理>F处理的趋势。紫云英DOM主要在耕作层和中层(20-40cm)土壤中迁移,YJ、NC、FC试验点中,F+M处理耕作层土壤中DOC含量比F处理分别提高17.0%、58.1%和33.7%,中层土壤中DOC含量分别提高43.0%、36.7%和11.2%。种植和翻压紫云英降低了DOM中类蛋白质组分的占比,增加了类腐殖质组分的占比,耕作层、中层和深层土壤(40-60 cm)中,3个试验点F处理DOM中类蛋白质的平均占比分别为7.34%、16.7%、23.9%,占比分别是F+M处理的1.26、1.92和1.54倍。类蛋白质组分的深层迁移能力大于类腐殖质组分。逐步回归分析表明,有生物活性的Cd形态占比与土壤SOM、类色氨酸含量存在负相关关系,与类富里酸含量存在正相关关系,其系数分别为-2.170、-0.760和0.239。常年种植和翻压紫云英通过影响土壤SOM总量以及DOM组分对土壤Cd表现出一定的活化潜力。

不同紫云英品种根瘤内生细菌的类群和多样性分析

【目的】阐释紫云英根瘤内生菌的群落结构,为研发根瘤菌菌剂及了解固氮机制提供依据。【方法】以福建省种植的不同紫云英品种的根瘤为材料,借助Illumina Miseq PE300测序平台,以16S rRNA基因为靶标,研究不同紫云英品种的根瘤内生细菌的多样性。【结果】不同品种会影响紫云英根瘤内生细菌的类群和多样性。浙紫5号(ZZ5)的优势属为假单胞菌属(Pseudomonas),其余品种根瘤内生细菌的优势属均为中慢生根瘤菌属(Mesorhizobium)。闽紫8号(MZ8)、信阳(XY)和浙紫5号的根瘤内生细菌的多样性指数(Shannon)较高,除了共生固氮的中慢生根瘤菌外,还包括丰富的非根瘤菌,如假单胞菌属、寡养单胞菌属(Stenotrophomonas)、杜擀氏菌属(Duganella)、泛菌属(Pantoea)、欧文氏菌属(Erwinia)等。闽紫8号、信阳和浙紫5号这3个品种根瘤中含有较高丰度的致病菌大黄欧文氏菌(Erwinia rhapontici)和菠萝泛菌PA13(Pantoea ananatis PA13)。【结论】紫云英品种对根瘤内生细菌的群落结构有一定影响,浙紫5号的根瘤内生细菌主要为具促生作用的非根瘤菌假单胞菌,而其余品种为具固氮能力的根瘤菌,在生产实际中可以采用紫云英混种的方式达到固氮促生的双重功效。

发光酶基因标记的华癸根瘤菌JS5A16L在紫云英根圈的定殖动态

在土壤一盒栽、盆栽微宇宙系统（Ｍｉｃｒｏｃｏｓｍ）中和田间条件下，研究了发光酶基因（ｌｕｘＡＢ）标记的华癸根瘤菌ＪＳ５Ａ１６Ｌ在紫云英根圈的定殖动态、分布范围及结瘤情况。在盒栽系统中，ＪＳ５Ａ１６Ｌ的定殖密度在紫云英出苗２天后达到最高水平（７．８８ ｌｐｇ ｃｆｕ／克根）（ｃｆｕ为ｃｏｌｏｎｙ ｆｏｒｍｉｎｇ ｕｎｉｔ的缩写），然后开始下降，并保持在一个相对稳定的水平；５８天后又有所回升，且能散布至种子下方２２ｃｍ处的根段部位。盆栽条件下的定殖动态与盒栽系统中的相似，紫云英播种３天后，ＪＳ５Ａ１６Ｌ可达最高定殖水平（６．９２ ｌｏｇ ｃｆｕ／株根系），随后开始缓慢下降，直至３２天时仍维持在一个相对稳定水平。ＪＳ５Ａ１６Ｌ在田间条件的定殖动态则不同，播种后３０天时定殖密度达到最大值（７ ．０３ ｌｏｇ ｃｆｕ／克根），９０天后降到最低值（５． ２４ ｌｏｇ ｃｆｕ／克根），然后又开始上升，１６０天时为７．８７ ｌｏｇ ｃｆｕ／克根，甚至在地上部植株收割后２０天仍可维持在７．８９ ｌｏｇ ｃｆｕ／克根。接种该菌株可显著提高紫云英的生物学产量。

汉中地区4种冬绿肥还田腐解和养分释放特征

研究汉中地区水稻(Oryza sativa)-绿肥轮作制下翻压还田绿肥的腐解动态变化及养分释放特征,可为水稻-绿肥轮作生产中的水稻科学施肥提供理论依据。以紫云英(Astragalus sinicus)、毛叶苕子(Vicia villosa)、山黧豆(Lathyrus cicera)和箭筈豌豆(Vicia sativa)为供试材料,进行145 d的田间原位埋袋腐解试验,并定期观测4种豆科绿肥腐解变化及养分释放特征。结果表明,绿肥腐解及养分释放均表现为前期(0~14 d)快、后期(41~145 d)慢。经过145 d,紫云英、毛叶苕子、山黧豆和箭筈豌豆的累计腐解率分别为74.58%、74.17%、72.14%和72.57%,而氮、磷、钾平均累计释放率分别为85.64%、75.23%和96.22%。翻压量为22500 kg·hm^(-2)的紫云英、毛叶苕子、山黧豆和箭筈豌豆腐解145 d后,氮素累计释放量分别为82.27、134.73、144.73和94.17 kg·hm^(-2),磷素累计释放量分别为14.68、21.39、21.21和17.25 kg·hm^(-2),钾素累计释放量分别为70.90、93.72、85.23和82.13 kg·hm^(-2)。4种绿肥的氮、磷、钾平均累计释放量分别为113.99、18.63和83.02 kg·hm^(-2),可为后茬水稻提供63.33%N、20.70%P2O5和79.07%K2O。综上,紫云英、毛叶苕子、山黧豆和箭筈豌豆均适于汉中地区冬闲稻田种植,且理论化肥减量顺序为毛叶苕子≈山黧豆>箭筈豌豆>紫云英,此外,水稻生育前期氮和钾减施潜力较大,建议水稻季氮肥和钾肥后移施用。

L-精氨酸联合黄芪治疗胎儿生长受限

目的探讨L-精氨酸联合黄芪治疗胎儿生长受限(FGR)的临床疗效。方法 FGR患者120例,随机分为常规治疗组、L-精氨酸组(常规治疗+L-精氨酸15 g加入体积分数5%葡萄糖500 mL静脉滴注)和L-精氨酸联合黄芪治疗组(常规治疗+L-精氨酸15 g加入体积分数5%葡萄糖500 mL静脉滴注+黄芪20 mL加入体积分数5%葡萄糖250 mL静脉滴注),每组40例。随机选择正常妊娠者40例为正常对照组。孕期定期B超监测胎儿生长发育参数及脐血流变化,产后比较新生儿出生体质量和围生儿结局。结果 L-精氨酸联合黄芪治疗组与常规治疗组、L-精氨酸组比较,小于胎龄儿的发生率下降,差异有统计学意义(P<0.05);L-精氨酸联合黄芪治疗组新生儿平均出生体质量高于常规治疗组和L-精氨酸治疗组,差异有统计学意义(P<0.05)。治疗后L-精氨酸联合黄芪治疗组双顶径(BPD)、腹横径(AD)、胸径(CD)、股骨长(FL)及腹围(AC)均高于L-精氨酸治疗组,差异有统计学意义(P<0.05);L-精氨酸治疗组BPD、AD、CD、FL及AC均高于常规治疗组,差异有统计学意义(P<0.05)。治疗后L-精氨酸治疗组、L-精氨酸联合黄芪治疗组与常规治疗组比较,收缩期峰值/舒张期峰值比率(S/D)、搏动指数(PI)及阻力指数(RI)均下降,而快速血流比值(FBVR)升高(P<0.05)。结论 L-精氨酸联合黄芪能有效改善胎儿胎盘血供,促进胎儿生长发育,增加新生儿出生体质量,降低小于胎龄儿的发病率。

黄芪多糖对脂多糖诱导人THP21单核细胞MCP-1与IL-6表达的影响

目的通过研究黄芪多糖(astragalus polysaccharide,APS)对脂多糖(lipopolysaccharide,LPS)诱导人单核细胞株THP21细胞趋化蛋白1(monocy techemoattractant protein1,MCP-1)及白介素6(interleukin-6,IL-6)的表达影响,探讨炎症状态下APS对单核细胞炎症因子表达的调控。方法体外培养人单核细胞THP21,以脂多糖刺激建立炎症细胞模型。以MTT法检测黄芪多糖对细胞的毒性,以荧光定量RT-PCR法检测黄芪多糖对THP21细胞MCP-1与IL-6mRNA水平表达的影响,以ELISA法检测黄芪多糖对THP21细胞MCP-1与IL-6细胞外分泌的影响。结果黄芪多糖在50、100、200μg/mL浓度下对THP21细胞均无明显毒性,100μg/mL的黄芪多糖明显抑制LPS诱导THP21细胞MCP-1与IL-6mRNA表达的增加及培养上清中MCP-1与IL-6的增加。结论黄芪多糖抑制脂多糖诱导的人单核细胞株THP21中MCP-1与IL-6的表达及分泌。

菜用紫云英中硒赋存形态及含硒有机化合物提取工艺研究

针对现蕾前菜用紫云英中硒的赋存形态不明确及含硒有机化合物的提取工艺不成熟的问题,以氢氧化钠溶液作为提取溶剂,研究了硒在菜用紫云英中的赋存形态。以有机硒提取率为指标,采用响应面分析法,考察了提取富硒菜用紫云英粉末中有机硒化合物的影响因素,并优化了主要含硒有机化合物的提取工艺。实验表明,紫云英中有机硒含量占总硒的92.49%,其中碱溶蛋白硒占总硒的69.45%;有机硒的最佳提取工艺条件是:氢氧化钠溶液的摩尔浓度为0.15 mol/L,氢氧化钠溶液用量为样品体积的20倍,提取时间为2 h,提取次数为2次。结果说明,紫云英中的硒以有机结合态为主,有机结合态硒在碱性溶液中提取效果最好,在对紫云英中有机硒进行提取时,主要应考虑提取溶液的酸碱性、提取溶液的用量、提取时间及提取次数等因素。该结果可为菜用紫云英的进一步开发利用提供科学依据。

黄芪总黄酮对急性心肌梗死大鼠心室肌细胞L-型钙电流及钠电流的作用

目的研究黄芪总黄酮（TFA）对急性心肌梗死（Am）大鼠心室肌细胞L-型钙电流（L—ICa）及钠电流（INa）的作用。方法设正常对照组、AMI组及TFA实验组。大鼠开胸左前降支结扎造成AMI，开胸前5min实验组大鼠舌静脉注射剂量为20mg／kg的TFA溶液50ul。用胶原酶酶解法急性分离AMI模型大鼠心室肌细胞，采用全细胞膜片钳记录技术记录左前降支供血区心外膜细胞的L—ICa及INa的作用。结果①应用TFA（20mg／kg）后，L—ICa从（0．313±0．14）nA增加到（0．402±0．27）nA，差异有统计学意义（P〈0．01，n=6）。②应用TFA（20mg／kg）后与对照组比较，峰值从（-8．43±2，03）nA下降到（-6．37±1．58）nA，差异有统计学意义（P〈0．01，n=6）。结论TFA可以增加AMI大鼠心室肌细胞L—ICa的幅值，TFA可显著降低AMI大鼠心室肌细胞INa的幅值。

紫云英与油菜混播还田对湘南稻田的影响

为探究湘南地区稻田中紫云英与油菜混播对后茬水稻产量以及土壤养分的影响,本试验设置6个处理,分别为冬闲(CK)、单播紫云英(LF01)、单播油菜(LF02)和紫云英油菜混播(LF03—LF05),对比分析各处理组绿肥生物量、后茬水稻产量及土壤理化性状等。结果表明,紫云英与油菜混播处理的绿肥生物量明显高于单播处理,其中紫云英播种量22.5 kg/hm^(2),油菜播种量3.0 kg/hm^(2)(LF04)时效果最佳,较紫云英单播和油菜单播分别增加120.9%和39.3%;同时LF04处理较CK处理后茬水稻产量增加17.5%;土壤中有机质、碱解氮、有效磷和速效钾含量分别提升了9.6%、8.1%、7.5%和9.6%。在湘南地区,相比紫云英、油菜单独播种,紫云英与油菜混播能够有效提高后茬水稻产量、改善土壤肥力,是一种有效的种植模式,适宜在该地区推广。

紫云英对土壤及生态环境的影响分析

随着社会经济和科学技术的高质量发展,人们的生活水平逐步提升,对绿色、多样化食品的需求逐渐增加。本研究对紫云英基本情况和种植方法进行介绍,就紫云英对土壤及生态环境的影响进行分析,研究发现种植紫云英能够提高作物产量,减少病虫害发生,提升土壤质量,改善农业生态环境,促进相关产业发展,为进一步推广紫云英种植提供借鉴。

“Co-culture Engineering”for Enhanced Phytoremediation of Metal Contaminated Soils

A co-culture of two plant materials, Astragalus sinicus L., a leguminous plant with concomitant nodules, and Elsholtzia splendens Naki-a Cu accumulator, along with treatments of a chelating agent (EDTA), root excretions (citric acid), and a control with E. splendens only were used to compare the mobility of heavy metals in chelating agents with a co-culture and to determine the potential for co-culture phytoremediation in heavy metal contaminated soils. The root uptake for Cu, Zn, and Pb in all treatments was significantly greater (P ＜ 0.05) than that of the control treatment. However with translocation in the shoots, only Cu, Zn, and Pb in plants grown with the EDTA treatment and Zn in plants cocropped with the A. sinicus treatment increased significantly (P ＜ 0.05). In addition, when a co-culture in soils with heavy and moderate contamination was compared, for roots in moderately contaminated soils only Zn concentration was significantly less (P ＜ 0.05) than that of heavily contaminated soils, however, Cu, Zn, and Pb concentrations of shoots were all significantly lower (P ＜ 0.05). Overall, this 'co-culture engineering' could be as effective as or even more effective than chelating agents, thereby preventing plant metal toxicity and metal leaching in soils as was usually observed in chelate-enhanced phytoremediation.

The Present Situation and Prospect of the Study on Locoweed in China

Locoweed is one of main poisonous plants in the world, and also is the most important toxic plant in grassland of China. The distribution range of the locoweed is extending continuously and it has formed or is coming into dominant species gradually in some areas in recent years, which cause the retrogressive succession and grazer poisoning and died in rangeland. Locoweed seriously threatened the grassland agriculture and made typical 'ecology-economic sick' in above district. Based on the investigation, research, prevention and cure practice to the locoweed for more than ten years, this paper reviewed the present situation and prospect of the studies on the locoweed in China, which include the researches of it's biological characteristics, distribution, ecological environment, harmfulness, prevention, weeding, utilization and ecological control etc.