丛枝菌根真菌提高植物非生物胁迫耐受性研究进展

丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF或AM真菌)是一种在土壤中广泛存在的有益真菌,能与地球上80％左右陆生植物根系共生形成丛枝菌根结构.AM真菌能通过与宿主植物交换碳源,促进宿主植物对N和P等无机营养元素的吸收,提高植株生产力和抵抗非生物胁迫的能力.全球气候变化和化肥农药的使用...     

菌根生理机能及其在污染土壤修复中的应用

伴随工农业生产的迅猛发展及人口的快速增长,环境污染日益加剧,土壤成了直接受害者,土壤污染的治理迫在眉睫.治理污染土壤的方法很多,其中菌根修复是近年来发展起来的利用真菌和植物根系形成共生体的一种生物修复方法.本文概述了菌根在生态系统中的重要性,讨论了菌根增强植物在各种胁迫环境中的耐受性及其机理,并对国内外利用菌根生物技术修复受污染土壤的研究作了介绍,旨在为菌根修复的应用提供科学依据.     

长额象鼻溞对海水盐度的适应性

在室内采用实验生态学方法,于（25±1）℃恒温条件下研究了不同盐度（0．1、0．5、1．0、1．5）对长额象鼻溢Bosmina longirostris生长、存活、繁殖和内禀增长率的影响。结果表明：长额象鼻涵是一种对盐度急变的耐受性极低和对盐度变化极为敏感的淡水枝角类,该溢24h LC50为4．62,生活的最适盐度为0．1—0．5,盐度仅在很低和微小增加时,才对其生活的某些方面有积极的影响;该潘的内禀增长率（rm）为0．241d^-1,低于其他种类,开发作为经济水产动物活饵料的潜力不大;从对盐度变化的敏感性来看,该涵有可能作为淡水污染、盐碱化等方面的监测生物,对环保、饮用水的生物监测具有重要意义。     

种植者2号(PlantersⅡ)肥料成分及特性分析

简述了微肥的应用现状,重点介绍了美国土壤公司开发的微量元素肥料种植者2号的营养成分、肥料特性及施用效果。种植者2号肥料以天然矿物为原料,含有铁、锌、钼、铜、锰、硼、钴、氯等作物生长发育所需的各种微量元素,具有酸碱耐受性、生物活性,所含矿物营养可直接被植物吸收利用。种植者2号不仅适用于传统农场、牧场及普通作物、转基因作物,也可用于有机认证农场与有机农作物的生产,对粮食作物、豆类作物、水果、林木、牧草、畜禽等均可实现较好的增产效果。实践证明,种植者2号具有良好的经济效益和环境效益。     

盐酸多西环素缓释注射液的安全毒性试验

报道了盐酸多西环素缓释注射液对昆明系小白鼠的急性毒性、蓄积毒性、耐受性和对靶动物的安全性试验的结果。采用改良krber法测得小白鼠LD50为304.8mg·kg-1,95%的可信限为263.0～353.2mg·kg-1;采用剂量定期递增染毒法测得对小白鼠的蓄积系数大于5.3;小白鼠对该药无耐受性(与空白对照组比较P>0.05);靶动物安全性试验中未出现不良反应。试验表明盐酸多西环素缓释注射液按临床拟用剂量使用安全。     

对低磷土壤有耐受牲的水稻

水稻是亚洲很多地方的主要粮食作物。但该地区的水稻存在诸多问题，如产量低、磷肥供应有限、雨水栽培系统易受气候变化影响等等。在这项研究中，Sigrid Heuer及其同事报告了对一个被称为＂磷缺乏耐受性-1＂（PSTOLl）的基因（使水稻对缺磷产生耐受性）的定性。     

Preparation of Pectin/Chitosan Synbiotic Microcapsules and Its Study on Simulated Gastrointestinal Environments and Storage Stability

Pediococcus acidilactici and inulin were used as wall cores,with pectin and chitosan as the shell material.The conditions of microencapsulation were optimized by analyzing the embedding rate,particle morphology,the mechanical strength,gastrointestinal tolerance in vitro and storage performance.The experimental group was divided into three groups:Free Pediococcus acidilactici group (PA),microcapsule group made by embedding Pediococcus acidilactici alone (PC(PA)MCs),synbiotic microcapsule group made by embedding inulin and Pediococcus acidilactici (PC(PA-I)MCs).The results showed that the appearance,particle size,mechanical strength and embedding rate of microcapsules were better when the mass concentration of pectin was 5 g/100 mL,the content of inulin was 25 mg/mL and the mass concentration of chitosan was 0.8 g/100 mL.Through the gastrointestinal tolerance test in vitro, it was found that PC(PA-I)MCs group was relatively stable in the artificial gastric juice in vitro (P<0.05).At the same time,it began to release rapidly in the artificial intestinal fluid in vitro at 30 min and it was almost completely disintegrated after 2 h.It was found that the cell survival rate of PA group decreased significantly at cold and room temperature through the storage test for 4 weeks.While the cell survival rate of PC(PA-I)MCs group decreased slightly.And the cell survival rate of PC(PA-I)MCs group was higher than that of PC(PA)MCs group (P>0.05).At room temperature,the cell survival rate of PC(PA-I)MCs group was higher than that of PC(PA)MCs group (P>0.05).In summary,pectin/chitosan microcapsules with inulin as probiotics had a better embedding effect on Pediococcus acidilactici.     

Cold tolerance of Acacia karroo and A. nilotica, two tree species from South Africa, in Beijing

Fynbos plant communities developed under geographic and climatic conditions unique to South Africa. Acacia karroo is the most widespread tree species, well known for its drought tolerance. A. nilotica exudes a good quality gum which is edible and suitable for confectionery. The two species have been introduced to China but little is known about their adaptability under the new environmental conditions. For our present study, the growth potential and physiological and biochemical parameters of the two species in response to cold stress were investigated. The results, measured as seed qualities (purity, thousand seed weights, germination, etc.) show differences between A. karroo and A. nilotica. The seed germination rate was between 10% and 60%. Seedlings were established in fields, pots and plugs. Those in the field grew well during the growing season but completely died in the winter. Those in pots or plugs were moved to and managed in the greenhouse. The plants were green in winter. The electrical conductivity of cells, the contents of water soluble sugars, proteins, malondialdehyde (MDA) increased during eight hours of low temperature treatment at 4℃. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) decreased markedly during the eight hours of 4℃treatment. We conclude that A. karroo and A. nilotica have little adaptability to the cold winter weather and cannot survive in the outdoors in the Beijing area, but could grow well indoors as ornamentals.     

大口黑鲈对饲料中乙氧基喹啉的耐受性评价

本试验旨在通过生长性能、抗氧化应答和肝脏组织学变化研究大口黑鲈对乙氧基喹啉的耐受性。在基础饲料中依次添加0(FFO组)、150(FFO-150组)、300(FFO-300组)和1 500 mg/kg(FFO-1500组)的乙氧基喹啉,其中300和1 500 mg/kg分别是欧盟最高推荐剂量(150 mg/kg)的2和10倍。另设1个负对照组(OFO组),即以氧化鱼油替换基础饲料中的新鲜鱼油。以初始体重为(4.01±0.01)g的大口黑鲈为靶动物,进行为期10周的生长试验,每组6个重复,每个重复30尾鱼。结果表明:OFO组的生长性能最差,其余各组增重率、特定生长率、饲料系数、摄食率均差异不显著(P0.05)。此外,FFO-300和FFO-1500组的存活率显著高于OFO和FFO组(P0.05)。FFO-150组的肥满度显著高于OFO组(P0.05);FFO-1500组的脏体比、肝体比与FFO组差异不显著(P0.05),但显著高于其他各组(P0.05)。FFO-300、FFO-1500组的肝脏谷胱甘肽硫转移酶活性显著高于其他组(P0.05)。饲料中添加300和1 500 mg/kg乙氧基喹啉可以显著提高大口黑鲈肌肉中超氧化物歧化酶活性和总抗氧化能力(P0.05)。乙氧基喹啉的添加对大口黑鲈鳃中抗氧化酶活性的影响无规律性变化。大口黑鲈心脏中过氧化氢酶活性、总抗氧化能力由于乙氧基喹啉的添加而显著降低(P0.05)。肝脏、鳃、心脏中丙二醛含量随乙氧基喹啉添加量增加呈下降趋势。各组大口黑鲈的肝脏有不同程度的损伤,但FFO-150、FFO-1500组的损伤相对比较少。由此得出,饲料中添加150 mg/kg乙氧基喹啉具有一定的抗氧化保护作用且对大口黑鲈是安全的,安全系数为10倍。但从存活率和抗氧化保护功能来看,建议大口黑鲈饲料中乙氧基喹啉的最高推荐量为300 mg/kg。     

大薸对奶厅废水主要污染物的去除效果研究

为探索低成本高效率的奶厅废水处理新技术,本研究以大薸（Pistia stratiotes）为研究对象,选择某奶牛养殖场奶厅废水原水、厌氧处理后和好氧处理后的废水开展室内试验,重点研究大薸对奶厅废水中主要胁迫盐分的耐受浓度阈值,以及大薸对奶厅废水中基础养分（TN、TP、COD等）和阴离子盐（SO₄^2-、Cl^-等）的去除效果。结果表明：当奶厅废水的电导率未超过2 193~2 527 μS·cm^-1时,大薸对奶厅废水中的盐分具有耐受性。但当奶厅废水中两种主要阴离子盐SO₄^2-和Cl^-含量分别超过5 mmol·L^-1和15~25mmol·L^-1时,大薸抗氧化酶活性受到抑制。在净化三类奶厅废水的过程中,大薸对水体COD的削减作用最为明显,减少了65.51%~86.75%,TN、NH₄⁺-N和TP含量分别降低了69.46%~87.52%、64.00%~96.59%和30.73%~66.02%,而SO₄^2-和Cl^-分别被大薸吸收了16.37%~18.04%和22.02%~35.83%。此外,大薸处理时间为23 d时,对奶厅废水原水和厌氧处理后的废水中多种污染物的去除效果最好。奶厅废水经厌氧处理后,大薸对多种污染物的削减作用更为明显,对水体中TN、NH₄⁺-N、TOC、SO₄^2-和Cl^-的去除效果较原水分别提升了9.60%、42.83%、40.94%、2.00%和13.81%。研究表明,大薸对奶厅废水中盐分具有耐受性,且奶厅废水经厌氧处理后大薸可以更为有效地降低其中主要污染物含量。