不同生长年限人参地土壤微生物多样性研究初报

不同生长年限人参地土壤微生物多样性研究结果表明,随着人参生长年限的增加人参根际微生物(含拮抗微生物)种类和数量有增多的趋势,其中6年生人参地人参根际微生物(含拮抗微生物)数量最多,人参生长4～8年的人参地微生物(含拮抗微生物)种类基本趋向稳定;而人参收获后撂荒5年的人参地中微生物(含拮抗微生物)种类和数量有明显增加的趋...     

Preparation of Denitrifying Phosphorus Accumulating Bacterial Seed Liquid and Analysis of Phosphorus Removal Mechanism

In order to control the water eutrophication, microorganism agents with high capability of denitrifying phosphorus accumulation are required. A denitrifying poly-phosphate accumulating organisms(DNPAOS), B8(Pseudomonas putida sp.)was isolated from activated sludge in oxidation ditch of Anhui Tianchang wastewater treatment plant. Intracellular polyphosphate granule(Poly-P)dyeing method was used to optimize the culture conditions of Poly-P-producing Pseudomonas putida strain B8 seed liquid. The results showed that the appropriate culture conditions were as follow: pH value and temperature ranged from 6.5 to 7.0 and 30~32 ℃m respectively. The saturation values of dissolved oxygen varied from 70% to 88%(when velocity was in range of 120~140 r/min), 15~20 h proved to be the cultivation time. The seed liquid produced by B8 showed high phosphorus uptake rate in the processes of anaerobic-anoxic and anaerobic-aerobic in wastewater(89.73% and 94.09% respectively)In the anaerobic-anoxic process, the highest nitrate removal efficiency was 53.48%. Extracellular polymeric substances(EPS)extracting method and analysis of phosphorus removal characterization revealed that phosphorus removal was mainly caused by intracellular uptake, rather than by extracellular biological adsorption.     

Effect of effective microorganism and gypsum amendments on nutrient leaching,pH, electrical conductivity,and Okra growth parameters under coastal saline soil

Nutrients losses through leaching are the main problem facing coastal saline soil. Effective microorganisms (EM) and Gypsum (G) at the application rate of 5%G and 10%G by weight were used as soil amendments. The pot experiment aimed to improve the leaching of nitrate (NO₃), ammonium (NH₄) and total nitrogen (TN) on the coastal saline soil. The EM+ 5%G treatment effectively reduced the content of NO₃ and NH₄ in the leachate by 86.59% and 68.18%, respectively. EM treatment reduced the leaching of NO₃ and NH₄ by 70.86% and 62.12% and EM+ 10%G reduced NO₃ and NH₄ by 11.80% and 50.76%, respectively. Moreover, the content of TN in leachate was reduced up to 13.23%, 5.80%, and 2.67% in response to EM, EM+ 5%G, and EM+ 10%G, respectively, compared to the control. These results indicate that EM combined with G as soil amendments can reduce leaching of nutrients and further support the regulation of a coastal saline soil pH and EC.     

氢气对植物生理功能的影响及作用机制研究进展

氢气(H_2)作为一种新型抗氧化剂广泛用于临床治疗中且疗效良好。植物体内可产生H_2,且在生长发育和胁迫应答等过程中发挥重要作用。综述了内源性H2在植物中的产生以及外源H_2处理对植物的生长发育、抗逆性、根际微生物和采后保鲜等的影响及其作用机制,并进一步探讨了H_2与其他植物激素和内源性小分子气体的交叉作用,为H_2在植物生理作用中的深入研究和应用奠定理论基础。     

有效微生物群对仔猪生产性能的影响初探

对产后母猪和断奶仔猪饲喂有效微生物菌群(EM),研究其对仔猪生产性能的影响。从产前7d开始给母猪基础饲料中添加5mL/kg的EM菌液,选产仔数不少于8头的3头母猪及其仔猪连续饲喂EM菌28d,仔猪进行断奶,统计母猪的增重、仔猪初生重、断奶重,仔猪成活率等,分析添加EM菌后对母猪生产性能的影响。在这24头断奶仔猪饲料中添加EM菌的饲料,饲喂至60日龄,统计仔猪的增重、采食量、料重比、发病数等,分析EM菌断奶仔猪生产性能的影响。另外选取3头同品种、同批次生产、产仔数相同的母猪及其仔猪饲料中不添加EM菌作为对照。结果表明,母猪产后日均采食量较对照组提高12.07%,仔猪的初生重较对照组提高15.90%,产活仔数提高了12.09%,断奶重增加9.09%,断奶头数增多20.99%,断奶成活率提高8.81%。断奶后仔猪试验组的平均采食量较对照组提高10.26%,料重比降低了7.14%,发病率下降了50.03%。说明EM菌对母猪和仔猪的生产性能均有提高作用,研究结果为EM菌在生猪养殖中的应用提供了基础资料。     

微生物肥料对青梗花椰菜生长和土壤微生物特性的影响

以微生物肥料不同施用方式[A(不施肥,CK);B(施微生物肥料);C(70%化肥+微生物肥料);D(100%化肥)]进行田间试验,研究其对青梗花椰菜(Brassica oleracea)生物指标和土壤微生物学指标的影响,为寻找合理的施肥方案提供理论依据。结果表明,与CK相比,处理B、C、D可不同程度地提高青梗花椰菜株高、茎粗、叶片数等生物指标和土壤微生物学指标。不同处理下土壤微生物数量、微生物生物量均随土层的加深而降低。不同施肥处理下微生物数量表现为细菌放线菌真菌。其中,处理C效果最佳,与处理D相比,青梗花椰菜株高、茎粗、叶片数、地上鲜重、地上干重、地下鲜重、地下干重、细菌数量、放线菌数量、微生物总数、土壤微生物生物量碳、土壤微生物生物量氮和土壤微生物生物量磷分别增加了6.82%、11.53%、11.76%、9.68%、33.33%、62.5%、33.33%、34.04%~37.61%、8.42%~15.87%、32.53%~33.86%、13.56%~18.6%、3.99%、12.81%~17.99%,真菌数量减少了26.23%~32.89%。不同施肥处理下土壤微生物生物量与微生物数量存在一定程度的正相关关系。因此,70%化肥+微生物肥料对青梗花椰菜生长具有良好的促进效果。     

EM发酵有机肥对油菜生物性状及重金属含量的影响

采用盆栽定位试验的方法研究了EM菌剂发酵有机肥料与化肥配施对油菜生长及硝酸盐、VC及重金属铅、汞含量的影响。结果表明:在试验范围内,EM菌剂发酵有机肥料与化肥配施,油菜的生物量比对照增加132.0%,VC含量较对照增加36.4%;硝酸盐含量降低20.9%,铅、汞含量分别降低37.4%和36.8%。EM菌剂发酵有机肥料与化肥配施,可以协调土壤生态肥力,降低油菜对重金属和硝酸盐的吸收,改善油菜生长与品质。     

紫色土中联苯菊酯残留对土著微生物的影响

为了阐明紫色土农药残留的生态环境效应特征及土壤微生物响应机理,以三峡库区具代表性的紫色土为材料,通过玉米盆栽模拟试验和平板计数法,研究了残留态联苯菊酯对紫色土土著微生物数量的影响。结果表明,低浓度联苯菊酯对土著细菌和放线菌有显著的促生效应,依联苯菊酯浓度从低到高,土壤细菌和放线菌数量随时间逐次出现最高峰值：第6天,LB-L处理下的细菌和放线菌数分别达9.02×106 个/g和2.77×106 个/g,约为相应对照的9倍和3倍;第11天,LB-M的细菌数约为对照的77倍,达到5.19×107 个/g;第16天时,LB-H的细菌数为1.71×107 个/g,LB-M和LB-H处理下的放线菌数分别为4.04×106 个/g、4.35×106 个/g。其次,联苯菊酯残留对土著真菌有显著且迅速的抑制作用,即使在2.50 mg/kg残留水平下,真菌数量也会在施加联苯菊酯后第2天发生显著降低。再次,紫色土中3种土著微生物类群对残留态联苯菊酯均表现出一定的生态适应性,但表现有所不同：土著细菌的生态响应存在阈值,土著放线菌表现为较长时期内稳定的促生效应,土著真菌则表现为可恢复的抑制效应。试验表明,土壤微生物数量等生物因素可作为联苯菊酯对紫色土根际微生态影响的重要评价指标。     

Impact of effective microorganisms and other biofertilizers on soil microbial characteristics,organic‐matter decomposition,and plant growth

Incubation and pot experiments were conducted to investigate the impact of commercially distributed biofertilizers (effective microorganisms [EM], BIOSTIMULATOR, BACTOFIL‐A, and BACTOFIL‐B) on soil microbial‐biomass content and activity, net N mineralization in soil, and growth of Lolium perenne. According to the manufacturers, the products tested are based on microbial inoculants or organic growth stimulants, and are supposed to influence soil microbial properties and improve soil conditions, organic‐matter decomposition, and plant growth. In the incubation experiment (40 d, 20.6°C, 50% maximum water‐holding capacity), EM was repeatedly applied to soil together with different organic amendments (nonamended, chopped straw, and lupine seed meal). Under the experimental conditions of this study, no or only marginal effects of EM on organic C, total N, and mineral N in soil could be observed. In soil treatments without any organic amendment, EM suspension slightly enhanced microbial activity measured as soil CO₂ evolution. In soil with easily degradable plant residues (lupine seed meal), EM suspension had a suppressive effect on microbial biomass. However, comparisons with sterilized EM and molasses as the main additive in EM suspension showed that any effect of EM could be explained as a pure substrate effect without the influence of added living organisms. In the pot experiment with Lolium perenne (air‐conditioned greenhouse cabin, 87 d, 16.8°C, 130 klxh d^–1 light quantity), the products EM, BIOSTIMULATOR, BACTOFIL‐A, and BACTOFIL‐B were tested in soil with growing plants. The products were repeatedly applied for a period of 42 d. Within this study, no effects of the different biofertilizers on mineral N in soil were detectable. There were clear suppressive effects of all tested biofertilizers on microbial‐biomass content and activity. Comparisons with sterilized suspensions showed that the effects were not due to living microorganisms in the suspensions, but could be traced back to substrate‐induced processes.     

转双价棉种植对土壤酶活性及土壤微生物的影响

转 Bt＋CpTI基因棉因其具有强有效的杀虫性能,近年来种植面积不断扩大,其种植对土壤生态系统的影响是环境风险评价的重要组成部分。本研究以转基因双抗虫棉sGK321和亲本同源常规棉石远321为研究对象,通过比较分析了不同生育期（苗期、蕾期、花铃期、吐絮期）转双价基因棉与其非转基因棉亲本在大田条件下种植13年后,根围土壤酶活性（脲酶、碱性磷酸酶、过氧化氢酶）变化和土壤可培养微生物（细菌、真菌、放线菌）数量的变化。结果表明,转双价棉与常规棉根际土壤脲酶、过氧化氢酶和碱性磷酸酶活性以及土壤可培养细菌、真菌、放线菌数量随生育进程的推进变化趋势一致。土壤细菌和放线菌数量在同一时期均无显著差异;土壤脲酶、过氧化氢酶、碱性磷酸酶和土壤真菌数量在一些时期差异明显,转双价棉脲酶苗期、碱性磷酸酶苗期和蕾期,土壤可培养真菌数量花铃期低于常规棉,土壤过氧化氢酶苗期、碱性磷酸酶花铃期高于同源常规棉。聚类分析表明,土壤酶活性和土壤微生物种群数量变化主要受生育期的影响,而转双价 Bt＋CpTI种植对土壤酶活性和微生物影响是有限的。