自生固氮菌的固氮能力及其对春小麦生长发育的影响

为挑选具有高固氮能力的自生固氮菌菌株, 用乙炔还原法对甘肃省春小麦和玉米等非豆科作物根际土壤中分离所得的13株菌进行固氮酶活性测定, 并通过盆栽试验对其进行春小麦肥效试验.结果表明:供试13株自生固氮菌对春小麦籽粒、生物产量及其构成因素均有一定促进作用, N6、N10、N13、N14、N27和N42 6株菌对春小麦产量的促进作用相对较高, 具有一定的应用前景, 有望成为微生物肥料研制的菌种.其中N13对春小麦的增产效果最为明显, 与施同量肥料(1/3N)的对照相比, 籽粒增产66.04%, 生物产量增产54.19%, 穗重增加47.65%, 穗粒数增多37.91%, 千粒重增加20.42%, 株高增加5.16%, 穗长增加21.89%, 且具有较强的固氮能力, 每盆固氮量为212.55 mg, 固氮酶活性也显著高于其他菌株, 达到139.79 nmol(C2H4)·h-1·mL-1.     

Enriching Vermicompost Using P-solubilizing and N-fixing Bacteria under Different Temperature Conditions

In the present study we evaluated changes in phosphorus (P), nitrogen (N), and humic acid (HA) contents of vermicompost (VC) in response to temperature increases, and inoculation with N₂-fixing and P-solubilizing microbes. Inoculants of Pseudomonas and Azotobacter were prepared and used to inoculate VC that was kept at 28 and 41 °C. Biological and chemical parameters of the VC were evaluated at 0, 20, 40, and 60 days. As incubation duration increased, bacterial population, N, available P, and HA content increased while organic carbon and pH decreased. These changes were most rapid during the initial 40 days of the experiment, and slowed subsequently. Increasing temperature from 28 to 41 °C reduced bacterial population and the efficiency of these bacteria in improving VC quality. Overall, our results indicate that inoculation of VC with microbes holds promise as a means of increasing the quality of VC, while our increased temperature treatment was less effective.     

固氮菌的筛选及其对菜场垃圾堆肥化的影响

分别以可溶性淀粉、鼠李糖、蔗糖为唯一碳源的无氮培养基,从校园土壤中分离到褐球固氮菌(Azotobacter chroococcum)、维涅兰得固氮菌(A.vinelandii)和拜氏固氮菌(A.beijerinckii)三种菌种各2株菌株。将3种菌种单独及混合分别投加到菜场垃圾堆肥装置中。结果表明,接种混合固氮菌的菜场垃圾废物堆肥的全氮、铵态氮、硝态氮的含量最高,堆肥化所用的时间最短。接种一种固氮菌(褐球固氮菌、拜氏固氮菌或维涅兰得固氮菌)的也有所提高。     

Influence of Rhizobium/Azotobacter and Rhizobium/Azospirillum combined inoculation on mineral composition of faba bean (Vicia faba L.)

 Mixed inoculation of Vicia faba L. with four different Rhizobium/Azospirillum and Rhizobium/Azotobacter combinations led to changes in total content, concentration and/or distribution of the mineral macro- and micronutrients, K, P, Ca, Mg, Fe, B, Mn, Zn and Cu, when compared with plants inoculated with Rhizobium only. The effects varied to a great extent among the Azotobacter and Azospirillum strains selected for combined inoculation. Received: 6 June 1998     

生物有机肥对田间蔬菜根际土壤中病原菌和功能菌组成的影响

利用实时荧光定量PCR方法对田间条件下连作番茄和辣椒施用生物有机肥(BOF)和常规施肥(CK)的根际土壤微生物中青枯病原菌和功能菌群(固氮菌和荧光假单胞菌)的数量进行定量研究.结果表明:与CK相比,BOF处理的番茄和辣椒产量分别提高了26.0％和19.9％,青枯病发病率分别降低了41.5％和44.7％,番茄和辣椒植株根际土壤固氮菌数量分别增加了23.5％和25.8％、荧光假单胞菌数量分别增加了29.5％和20.2％、病原菌数量分别减少了73.2％和90.1％.生物有机肥能够调控根际微生物区系的组成,降低土传病害的发病率,促进作物健康生长;实时荧光定量PCR方法能够快速准确地检测根际土壤中功能微生物种群数量变化.     

Effect of P‐solubilizing Azotobacter chroococcum on N,P, K uptake in P‐responsive wheat genotypes grown under greenhouse conditions

Natural and mutant strains of A. chroococcum were isolated from Indian soils. Their ability to dissolve phosphate and their phytohormone production were tested under in vitro conditions. In addition the effect of bacterial inoculation of Azotobacter on N, P, K uptake by three P responsive wheat genotypes (Triticum aestivum L.) under greenhouse conditions at five nutrient levels (Control, 90 kg N ha^—1, 90 kg N + 26 kg P ha^—1, 120 kg N ha^—1 and 120 kg N + 26 kg P ha^—1) was studied. In vitro phosphate solubilization and growth hormone production by mutant strains was more than by the soil isolates. Inoculation of wheat varieties with the soil isolates and mutant strains of A. chroococcum showed greater NPK uptakes as compared with parent soil isolates. Mutant strains M15 and M37 were proved to be the most effective for all three wheat varieties with regard to NPK uptake as well as root biomass production under greenhouse conditions.     

拉萨长期不同施肥青稞田土壤固氮菌分离鉴定

为寻找拉萨青稞田自生固氮菌,丰富当地固氮菌资源,以减少化肥使用量,降低环境负效应,本研究从6种长期不同施肥模式定位试验的青稞田土壤中进行固氮菌的分离、纯化,观察其菌落形态特征并测定各菌株的固氮酶活性,通过16S rDNA基因测序和构建系统发育树分析了各菌株的分类学地位。结果显示,通过分离和纯化,共得到自生固氮菌50株,其中13株菌具有高效固氮酶活性,分别属于假食酸菌属(Pseudacidovorax)、芽孢杆菌属(Bacillus)、红球菌属(Rhodococcus)、农杆菌属(Agrobacterium)。施用化肥会减少土壤中高效固氮菌种类,不施化肥或施用有机肥能丰富土壤中高效固氮菌种类。     

两种引进菌剂对大豆生长和产量的影响

通过盆栽试验和大田试验,对两种新引进的菌剂对大豆生长和产量的影响进行了研究。结果表明:两种菌剂均有促进生长、增加产量和培肥土壤的效果,与CK相比,出苗早,发苗快,前期株高比CK分别增加7.27%和5.95%,中期株高比CK分别增加8.45%和8.11%,植株干重、根系长度、根系重量和大豆产量增加,土壤全氮、碱解氮、速效磷和速效钾含量增加。大豆专用菌剂处理的植株根部有根瘤形成。     

Integration of soil solarization and chemical sterilization with beneficial microorganisms for the control of white root rot and growth of nursery apple

White root rot (Dematophora necatrix (Mart.)) is a serious disease of apple (Malus domestica Borkh) in nurseries and orchards in India. In 2002 and 2003, field experiments were conducted to integrate soil solarization with native isolates of Azotobacter chrococcum and vesicular–arbuscular mycorrhizal fungi and observe its effect on the incidence of white root rot and growth of the saplings. Apple seeds coated with two native isolates of A. chrococcum (AZUHF₁ and AZUHF₂) were sown in plots inoculated with 4 native isolates of va-mycorrhiza, i.e. AMUHF₁ (Glomus fesiculatum), AMUHF₂ (Glomus macrocarpum), AMUHF₃ (Glomus mosseae) and AMUHF₄ (Gigaspora sp.) in 14 different combinations and these plots were solarized with transparent polyethylene mulch (25 μm thick) for 40 days in summer months. Soil solarization resulted around 9 °C higher temperature with average maximum temperature of 38–39 °C. Inoculation of saplings with AMUHF₁ isolate of va-mycorrhiza and AZUHF₁ isolate of A. chrococcum and then their planting in solarized soil was found most effective with no incidence of white root rot in comparison to 33.6–35.4% in control accompanied with 78–113% increase in shoot length and 81.6–84.3% increase in root length. Shoot and root length of the saplings was 9.6–10.6 and 9.2–16.0% higher, respectively, in solarized plots in comparison to sterilized plots.     

PGPRs affected photosynthetic capacity and nutrient uptake in different Salvia species

Abstract

In order to evaluate the effect of plant growth promoting rhizobacteria (PGPR) on photosynthetic capacity and nutrient uptake of three Salvia officinalis species, an experiment was conducted at the Agricultural Research Center of West Azerbaijan during 2015 and 2016. The experiment was conducted in split factorial based on randomized complete block design with three replications. The main plot included three species of Salvia officinalis (hybrid species), S. Sclarea, and S. nemorosa (both native species). The sub plot included the factorial treatment of nitrogen stabilizing bacteria in three levels (Azosprillium lipoferum, Azotobacter, and control), and phosphate solubilizing bacteria in three levels (Pseudomonas, Enterobacter, and control). Eventually, two years were combined into a compound analysis. The evaluated traits included plant height, leaf area, number of flowering branches, photosynthetic pigments (chlorophyll a, chlorophyll b, and total chlorophyll) and leaf nutrients uptake [(nitrogen (N), phosphorus (P), potassium (K)]. The results indicated a significant effect of the studied traits compared to the year (leaf area, number of flowering branches, chlorophyll a, chlorophyll b), cultivar, N stabilizing bacteria (except chlorophyll b) and phosphate solubilizing bacteria (p?<?0.01). The effect of quadruple interaction showed a significant effect (p?<?0.01) on all studied parameters except of plant height and leaf nutrients. The results indicated that leaf area and number of branches in the second year increased by 24.7 and 28.21%, respectively. The amount of chlorophyll a decreased in the second year, however chlorophyll b increased significantly and total chlorophyll did not change significantly. S. Sclarea produced the highest plant height (102.62?cm) and the highest leaf number (68.16) per plant. Further, the results showed that in all three species, Pseudomonas phosphate solubilizing bacteria had the highest effect on the leaf nutrient uptake and the combination of Pseudomonas with Azotobacter improved the nutrient uptake and the growth status of the plant.