Herbicide abuse has a significantly negative impact on soil microflora and further influences the ecological benefit. The regulating measures and corresponding mechanisms mitigating the decreased bacterial diversity due to herbicide use have rarely been studied. A field experiment containing the application gradient of an efficient maize herbicide thiencarbazone-methyl·isoxaflutole was performed. The relationship between soil bacterial community and thiencarbazone-methyl·isoxaflutole use was revealed. Modified attapulgite was added to explore its impacts on soil microflora under the thiencarbazone-methyl·isoxaflutole application. Based on the analytic network process–entropy weighting method–TOPSIS method model, the ecological benefit focusing on microbial responses was quantitatively estimated along with technical effectiveness and economic benefit. The results showed that the diversity indices of soil microflora, especially the Inv_Simpson index, were reduced at the recommended, 5 and 10 times the recommended dosages of thiencarbazone-methyl·isoxaflutole use. The Flavisolibacter bacteria was negatively correlated with the residues in soils based on the random forest model and correlation analysis, indicating a potential degrader of thiencarbazone-methyl·isoxaflutole residues. The structural equation model further confirmed that the high soil water content and soil pH promoted the function of Flavisolibacter bacteria, facilitated the dissipation of thiencarbazone-methyl·isoxaflutole residues and further improved the diversity of soil microflora. In addition, the presence of modified attapulgite was found to increase the soil pH, which may improve bacterial diversity through the regulating pathway. This explained the high ecological benefits of the treatment where the thiencarbazone-methyl·isoxaflutole was applied at the recommended dosage rates in conjunction with modified attapulgite addition. Therefore, the comprehensive benefits of thiencarbazone-methyl·isoxaflutole application with a focus on ecological benefits can be improved by regulating the soil pH with modified attapulgite.

采用通气法对设施菠菜和黄瓜在施用生物质炭与翻耕措施下土壤氨气(NH3)排放进行观测,探索设施菜地NH3减排的有效途径.观测表明,设施菠菜与黄瓜土壤NH3排放主要发生在施肥后一周内.在施化肥氮总量300 kg/hm2条件下,设施菠菜不施生物质炭和表施生物质炭处理的NH3排放量分别占总氮投入量的8.00％和10.15％,而翻耕措施分别降低各处理NH3排放38.34％和56.22％(P<0.05).在施化肥氮总量600 kg/hm2条件下,设施黄瓜不施生物质炭和表施生物质炭的NH3排放量分别占总氮投入量的3.03％和4.80％,而翻耕措施分别降低各处理NH3排放9.45％和37.61％.设施菜地表施生物质炭增加土壤NH3排放,其中菠菜和黄瓜单位产量的NH3排放量分别增加52.58％和78.17％(P<0.05).根据设施菜地NH3排放特点和不同处理的减排效果,建议减少基肥投入以控制NH3排放,并利用翻耕措施消除表施生物质炭对NH3排放的促进效应.

玉米和稻谷是南方地区重要的饲料原料来源.本研究采用LI-6800便携式光合作用测定系统观测了温度和CO2浓度对长江中游平原水稻和玉米扬花期功能叶片光合参数的影响.结果表明:玉米扬花期功能叶片净光合速率对温度升高的敏感性高于水稻.温度升高提高了水稻功能叶片的光合速率.CO2浓度增加提高了扬花期水稻和玉米的最大光合速率.当温度条件相同时,在高CO2浓度条件下水稻比玉米更容易维持较高的光合速率.玉米功能叶片最大电子传递速率(Jmax)与最大羧化速率(Vcmax)的比值(Jmax/Vcmax)随温度升高而显著下降(P<0.05),而水稻Jmax/Vcmax值对温度升高无显著变化.温度升高与CO2浓度增加均可降低两种作物的叶片气孔导度和植物蒸腾速率.本研究发现,玉米功能叶光合参数及生化参数对高温环境较为敏感,即玉米的光合酶活性和光合能力比水稻更容易受到温度升高的抑制作用.建议未来应重视气温升高对玉米饲料资源带来的不利影响,在畜禽养殖中合理调整饲料原料供给结构,适当将稻谷作为饲料原料的替代来源之一,可以抑制因玉米价格上涨造成的饲养成本攀升,提高养殖效益,为新形势下畜牧业发展探索一条高效、可持续的发展道路,提升畜牧业发展的竞争力.

烟叶原料发酵是决定雪茄品质与风味的关键因素之一,研究了雪茄烟叶不同发酵阶段的微生物多样性及蛋白酶、淀粉酶、果胶酶的变化规律.结果 表明,不同发酵阶段微生物菌群呈动态变化,样品1在发酵起始阶段以葡萄球菌属为优势菌,结束则以肠杆菌属、假单胞菌属、短杆菌属为优势菌;而样品2在发酵过程中主要以葡萄球菌和四联球菌为优势菌.不同发酵阶段酶活性变化规律具有一定差异性:样品1蛋白酶(165.95 U·g-1)与淀粉酶(0.34 U·g-1)在发酵结束活性较强,果胶酶活性(1.30 U·g-1)在发酵起始较强;样品2蛋白酶活性(121.57 U·g-1)发酵结束活性较强;果胶酶活性(1.60 U·g-1)与淀粉酶活性(0.38 U·g-1)在发酵中期活性较强.样品1雪茄原料在三个不同发酵阶段pH变化较为明显,在发酵中期pH为7.6,呈碱性;样品2雪茄原料在不同发酵阶段pH变化较小,整个发酵阶段pH呈酸性.

为了满足国家建设与发展的需求,在普通生态学教学的基础上要对教学模式以及教学方法进行改革与优化,才能够调动学生的学习积极性,提高学生的自主学习意识与创新能力.文中结合实际案例,在提高学生能力的基础上对普通生态学教学改革进行了探索与研究,旨在提高普通生态学的教学质量.

通过对北京市352个设施蔬菜地块的施肥状况进行实地调研,查明设施蔬菜施肥现状及存在问题,估算肥料减施潜力.结果表明,北京市设施蔬菜养分投入量普遍超过推荐施肥量(养分超标率>72％).不同设施类型施肥量差异较大,其中日光温室每季蔬菜平均氮磷钾(N、P2O5和K2O)投入总量分别为858、409、572 kg·hm-2,明显高于塑料大棚每季蔬菜平均氮磷钾投入总量593、317、438 kg·hm-2.设施蔬菜养分主要来源于有机肥基施,对日光温室和塑料大棚养分投入总量的贡献分别为66％ 和52％.不同蔬菜种类肥料减施潜力巨大,其中甘蓝、黄瓜和茄子总养分相对减施潜力分别为61％～62％、43％～48％ 和18％～47％.日光温室和塑料大棚氮磷钾养分投入比例(N:P2O5:K2O)分别为1:0.47:0.66和1:0.53:0.73,表明钾肥比例相对不足.建议加快设施蔬菜水肥一体化技术的推广应用,加强设施蔬菜施肥技术指导,尤其要降低日光温室的氮、磷肥投入量,避免过量施肥带来的资源浪费和环境污染.

“生态桥”治理工程是北京平谷区针对桃树枝废弃物资源化利用而提出一套废弃物资源化利用和乡村治理的模式,对于破解乡村环境治理困境具有重要意义.本研究分析了“生态桥”治理工程废弃物资源化利用和运行模式特征.结果 表明:“生态桥”治理工程通过堆制有机肥、食用菌栽培、制作栽培基质和地表覆盖物等资源化利用方式,打造桃树枝废弃物良性生态循环模式.在运行模式上,“生态桥”治理工程建立投融资平台,统筹资金使用与投入方式,建立起财政资金有效使用和管理办法,激发企业投入农村环境治理的动力,保障农民全员参与的机制.通过“生态桥”工程设施,吸引社会资本进入乡村环境治理领域,有效改善环境质量,推动乡村生态环境建设投融资机制改革,提高了乡村生态环境综合治理水平,是一种有效的乡村环境治理模式.

[目的]设施菜地存在施肥量过大、肥料利用率低、环境污染等问题.通过对天津市设施菜地施肥现状调查,明确设施菜地施肥现状和存在问题,为制定科学合理的施肥方案提供依据.[方法]本研究对天津市193个设施蔬菜地块施肥现状展开调查,明确设施菜地施肥特征,估算肥料总养分和化肥养分减施潜力.[结果]天津市日光温室平均养分施用总量为N 775.6 kg/hm2、P2O5715.5 kg/hm2和K2O 524.9 kg/hm2,显著大于塑料大棚对应养分平均施用总量N 670.9 kg/hm2、P2O5584.5 kg/hm2和K2O 425.3 kg/hm2(P＜ 0.05).有机肥是设施菜地养分的主要来源,对日光温室和塑料大棚N、P2O5和K2O各自施用总量的贡献均超过50％.日光温室和塑料大棚中,化肥对磷(P2O5)施用量的贡献分别为44.2％和48.8％.从养分施用方法看,N、P2O5和K2O基施比例日光温室分别为79.4％、80.2％和73.5％,塑料大棚分别为70.2％、78.2％和67.4％,P2O5基施比例大于N和K2O.日光温室和塑料大棚平均养分施用比例(N:P2O5:K2O)分别为1.00:0.92:0.69和1.00:0.87:0.63.相比推荐施肥量,天津市设施蔬菜N和P2O5普遍施用过量,甘蓝和白菜K2O投入不足.设施菜地总养分(N+P2O5+ K2O)减施潜力在31.5％～65.0％,化肥养分减施潜力在22.4％～66.6％.[结论]天津市设施菜地养分以基施为主,其中化肥基施比例偏高,追肥养分比例过低,养分总量过量施用现象普遍.设施菜地基施化肥和追肥中P2O5比例偏高,养分结构不合理.主要设施蔬菜中,茄子、番茄和芹菜的N和P2O5施用总量远超过各自推荐施肥量,化肥养分减施潜力较大,是设施蔬菜肥料减施关注的重点.

为阐明大气CO2浓度升高和氮肥交互作用对C4作物玉米光合生理和产量的影响,本研究利用自由大气CO2富集(FACE)平台,以玉米品种'郑单958'为试验材料,在不同施氮量[常氮180 kg(N)?hm-2、低氮72 kg(N)?hm-2]下比较大气CO2浓度[(400±15)μmol?mol-1]和高CO2浓度[(550±15)μmol?mol-1]对玉米生长的影响.结果表明:1)大气CO2浓度升高使玉米苗期叶片叶绿素浓度显著(P=0.025)增加9.5％,抽雄期净光合速率显著(P=0.009)增加9.0％;低氮和常氮下,高CO2浓度使玉米各主要生育期胞间CO2浓度分别显著增加34.8％～48.5％和40.0％～49.4％,气孔导度在大口期和抽雄期分别显著下降21.6％(P=0.015)和22.1％(P=0.010),玉米叶片水分利用效率在大口期、抽雄期和灌浆期分别显著增加12.9％(P=0.002)、9.8％(P=0.019)和18.8％(P=0.001);高CO2浓度使玉米非光化学淬灭呈降低趋势、PSII有效光化学量子产量有增加趋势;相同氮水平下,高CO2浓度对玉米产量没有显著影响.2)高CO2浓度和合理施氮交互作用对玉米功能叶叶绿素含量、净光合速率、PSⅡ有效光化学量子产量增加有一定的促进作用,如在大口期和抽雄期,常氮+高CO2浓度处理叶绿素含量比低氮+大气CO2浓度处理增加17.3％和10.7％,高CO2浓度和合理施氮量交互作用有增加玉米产量的潜力,合理增加施氮量促进了CO2肥效的发挥.在未来大气CO2浓度升高条件下合理施氮对C4作物玉米生长发育有促进作用.

"地质与地貌学"是一门理论性和实践性很强的课程,是农业资源与环境专业必修的一门专业基础课.采用互动式教学有效提高该课程学生的考试成绩.互动式教学方法是"地质与地貌学"课程教学模式改革的一种新途径,对本专业教学模式改革具有积极的意义.

We examined how Raoultella ornithinolytica-ZK4 degraded pyrethroid pesticides within soil sediment from an abandoned pesticide plant. Lambda-cypermethrin and deltamethrin are two pyrethroid insecticides with high insecticidal activity and a wide range of applications. However, their increased use has raised concerns regarding toxicity and accumulation. We isolated a strain of ZK4 (Raoultella ornithinolytica-ZK4) from soil taken from a channel that surrounded a pesticide plant. We used enzyme localization to study degrading bacteria ZK4. The ZK4 strain underwent intracellular enzyme degradation. The degradation rates of lambda-cyhalothrin and deltamethrin were 55% and 53%, respectively. The optimum pH of the two kinds of pyrethroids in ZK4 was 6.5, and their optimum temperature was 37 °C. The intracellular degradation of the crude enzyme produced by the ZK4 strain had a pH of 6.0–8.0 and a temperature of 20–42 °C. The ZK4 strain genome contained 5310 genes with a total length of 4,864,494 bp. Sugar metabolism and exogenous chemical metabolism accounted for the largest proportion of metabolic activities. We used the clusters of orthologous groups (COG) alignment and found numbers for 4686 protein sequences, accounting for 88.25% of the total predicted protein. ZK4 degraded lambda-cyhalothrin and deltamethrin, and may serve as a reference for the preparation of future degrading microbial agents to assist with environmental restoration efforts.

Deltamethrin is a pyrethroid insecticide with high insecticidal activity and a wide range of applications. However, with the increased amount and scope of its application, the accumulated toxicity of deltamethrin has gradually raised concerns. In this study, a bacterium strain, which used deltamethrin as its sole carbon source and was named ZJ6 (Lysinibacillus sp.-ZJ6), was isolated from soil samples collected from the sewage outlet of a pesticide plant in Tianjin. Based on morphological observations of ZJ6, as well as its physiological and biochemical characteristics and 16S rDNA sequence (Gen Bank Accession No. KU129013), the strain was identified as Lysinibacillus fusiformis sp.. A study of the degradation characteristics of ZJ6 revealed that the optimum conditions for shake flask fermentation to degrade deltamethrin by ZJ6 were as follows: pH 7.0, a temperature of 30 °C, a substrate concentration of 100–200 mg/L, an inoculation volume of 10%, and 7 days culturing at 160 rpm. Under these conditions, the degradation rate of deltamethrin by ZJ6 reached 57.2%. Preliminary sequencing of the ZJ6 genome showed that it has a total length of 3,921,852 bp and contains 4567 genes. The average length of each gene in the ZJ6 genome is 859 bp, and these genes account for 84.62% of the total genome length. KEGG metabolic pathway analysis revealed that genes involved in sugar metabolism and metabolism of exogenous chemical substances were significantly enriched in the genome of ZJ6. Comparison with the COG database showed that 2839 of the predicted protein sequences from the ZJ6 genome had COG numbers. Among all protein functions, the number of genes involved in general functions was the highest (372). For the first time, it was found that ZJ6 has relatively strong deltamethrin degradation ability and high value as a subject for further research. In addition, this study provides a reference to guide the preparation of pesticide-degrading bacterial agents and environmental remediation.

[Objective] Lawn plays an important role in maintaining ecological balance and environmental beautification.However,a large amount of water consumption in the plantation and conservation of lawn is contradicted with water shortage.Irrigation with reclaimed water is alternative pathway to alleviate this contradiction of water supply and demand.[Methods] In order to investigate the adaptability of turfgrass to the reclaimed water irrigation,five cool-season turfgrasses including Festuca arundinacea Schreb.'Plantation',Poa pratensis L.'Merit',Lolium perenne L.'Asther',F.rubra L.'Penny'and Agrostis plustris Hunds.'Putter'were used as plant materials.After four irrigation water treatments,domestic wastewater,scondary-grade reclaimed water,third-grade reclaimed water,and tap water,the apparent mass and ecophysiological indexes were measured.[Results] The third-grade reclaimed water was suitable to irrigate the turfgrasses,and F.arundinacea Schreb.'Plantation'showed the highest adapability,followed by F.rubra L.'Penny',P.pratensis L.'Merit',and A.plustris Hunds.'Putter'.

[目的]为了解重金属离子对土壤中百菌清光解的影响,选取污染土壤中常见重金属离子Cu(Ⅱ)、Cd(Ⅱ)、Cr(Ⅲ)进行光解试验.[方法]采用氙灯为入射光源,研究百菌清在添加Cu(Ⅱ)、Cd(Ⅱ)和Cr(Ⅲ)3种重金属的土壤表面的光解特征.[结果]在模拟太阳光照射下,百菌清在土壤表面的光解符合准一级反应动力学.3种重金属的添加对百菌清的光解起到显著的抑制作用.Cu(Ⅱ)(200 mg/kg)、Cd(Ⅱ)(10 mg/kg)和Cr(Ⅲ)(25 mg/kg)使百菌清的光解速率常数由原来的0.549 h-1分别降低为0.333、0.310和0.471 h-1.腐殖酸(humic acid,HA)对百菌清的光解起到光敏化促进作用.当土壤中添加1％、2％和3％的HA时,百菌清的光解速率常数由0.549 h-1分别提高到0.646、0.907和0.584 h-1.而当重金属与HA共存时,HA的光敏化作用受到显著抑制.HA添加浓度为1％时,Cu(Ⅱ)(200 mg/kg)、Cd(Ⅱ)(10 mg/kg)和Cr(Ⅲ)(25mg/kg)的加入分别使百菌清光解速率常数降低到添加1％HA时的43.5％、33.9％和17.5％.[结论]土壤表面的百菌清在光照下可发生较快的光解,但Cu(Ⅱ)、Cd(Ⅱ)、Cr(Ⅲ)等重金属的加入会降低百菌清的光解速率.

Objective: This study aimed to separate and pure chitinase producing actinomycetes with stronger activity from lawn soils of Beijing. Method: Morphology and culture characteristics were observed. physiological and biochemical characteristics were detected. 16SrDNA sequence was analyzed. Result: The highest chitinase activity strain was Bn035, whose relative diameter of transparent circle K2 was 3.42 at which the chitinase activity of fermentation broth reached a maximum value of 1.23 U/mL in the 6th day. Crude enzyme solution and bacteria cake of strain Bn035 generated stronger bacterial resistance to all root rot fungi which indicated that the strain had a strong broad-spectrum resistance to root rot fungi. Conclusion: The strain was identified as Streptomyces scabrisporus. It will be a potential biological control function.

[目的]为了深入了解粗糙脉胞菌类胡萝卜素合成调控机制.[方法]该研究通过对粗糙脉胞菌基因突变体库中6 087株突变体进行筛选,并对突变体类胡萝卜素与无性孢子的产量进行测定；最后采用实时荧光定量RT-PCR技术对无性产孢及类胡萝卜素合成相关基因进行转录分析.[结果]新发现6个基因敲除突变体营养生长正常,但类胡萝卜素的合成降低,其中表型较好的1个突变体,其无性产孢量与类胡萝卜素合成量均明显降低.该突变体所缺失的基因编码一种依赖ATP的染色体重建复合体的ATP酶链ISW1,我们将该基因命名为lca-1.进一步测定发现lca-1基因的突变导致无性产孢及类胡萝卜素的合成量较野生菌株分别降低了88％和81％.[结论]lca-1对脉胞菌的无性产孢和类胡萝卜素合成具有重要的正调控作用.

[Objective] This study aimed to investigate the regulatory mechanisms of carotenoid biosynthesis in Neurospora crassa.[Method] Gene knockout mutants producing less carotenoid were screened from 6 087 mutants;the yield of carotenoid and asexual spore was measured;finally fluorescent quantitative real-time PCR was adopted to analyze the transcription of genes related to carotenoid synthesis and asexual sporulation.[Result] Six knockout mutants produced less carotenoid.In one of them,the yield of both carotenoid and asexual spore reduced,because the gene which encodes an ATP-dependent chromatin remodelling complex ATPase chain ISW1 was knocked out.This gene was named lca-1 in this study.And the lca-1 deletion resulted in a reduction of 88% in conidial production and a decrease of 81% in carotenoid production.[Conclusion] The lca-1 positively regulates the carotenoid synthesis and asexual sporulation in N.crassa.

The controversy between act psychology and content psychology was the first controversy in the history of psychology.This controversy mainly focused on the research subject,the research method of psychology and psychological classification.It began with Brentano’s some misunderstanding about Wundt’s theory,which resulted in the appearance of dual psychology that tried to resolve.

Carotenoid is an antioxidative pigment providing protection against UV radiation in fungi.Neurospora crassa is one of a few fungi from which genes participate in carotenoid biosynthesis have been characterized.In order to investigate the regulatory mechanisms of carotenoid biosynthesis in N.crassa,we screened mutants for lower carotenoid production and found 6 belonging to this category from 6,087 gene knockout mutants.Among them,a mutant whose corresponding gene was named as lca-1 in this study was further investigated.lca-1 encodes a ATP-dependent chromatin remodeling complex ATPase chain ISW1.lca-1 deletion resulted in a reduction of 88% in conidial production and a decrease of 81% in carotenoid production.qRT-PCR analysis showed that the expression levels of the four genes (al-1,al-2,fl and eas) related to conidiation and carotenoid biosynthesis were reduced.These results suggest that lca-1 positively regulates conidiation and carotenoid biosynthesis in Neurospora.