不同耕作栽培环境对秸秆腐解剂腐解效果的影响

[目的]解决保护性耕作下大量秸秆覆盖地表对机械播种、种子出苗的影响,筛选出适宜的秸秆腐解剂,提供保护性耕作技术大面积推广的技术支撑。[方法]设置了温室、大田2种环境,研究了麦玉两熟区保护性耕作条件下不同腐解剂对秸秆腐解速度的影响。[结果]温室条件下秸秆腐解速度快于大田环境,这与温室所创造的高温、高湿条件有关。试验最初的5 d时间内,采用腐解剂处理的秸秆腐解速度高于对照处理的1倍以上,随时间的延长差距变小。同时,试验所用4种腐解剂对秸秆的腐解速度不同。[结论]通过筛选适宜的腐解剂,可以实现保护性耕作下秸秆的快速腐解,为机械播种及种苗发育创造条件。     

小麦蚕豆间作条件下不同施氮量对作物根际微生物数量的影响*

 通过盆栽试验和室内平板培养技术研究了小麦蚕豆间作条件下不同施氮量对作物根际微生物的影响。结果表明：小麦蚕豆根际微生物数量在总体上以细菌为主,放线菌次之,真菌最少。在作物各生育期,随着施氮量的增加,小麦、蚕豆根际微生物数量增加,在施氮量为325 mg/kg（N）时达到数量最高,高氮（N_3/2, 487.5 mg/kg）时下降。在小麦孕穗（蚕豆开花）期施氮量为325 mg/kg 时,间作小麦根际细菌、真菌和放线菌分别比对照（N₀）增加了71%,152%,4%;间作蚕豆根际细菌、真菌和放线菌分别比对照（N₀）增加了214%,65%,17%。小麦与蚕豆间作对小麦根际微生物数量表现为增加作用,但对蚕豆根际微生物的影响相反;间作小麦根际细菌、真菌数量在分蘖期、收获期显著高于单作小麦,间作蚕豆根际微生物数量在施氮量为325 mg/kg（N）时均低于单作蚕豆。施氮量与种植模式的互作效应在蚕豆分枝、开花和鼓粒期对蚕豆根际细菌、真菌有显著影响,对小麦根际细菌仅在分蘖期有显著影响,对小麦根际真菌仅在孕穗期有显著影响。     

解磷微生物研究现状及展望

磷是植物生长发育所必需的营养元素之一。土壤中能被植物吸收利用的有效态无机磷很低,一般只占全磷量的2％～3％,大部分很难被作物吸收     

解磷细菌对石灰性土壤磷形态的影响

从石灰性土壤中分离,筛选出解磷细菌,进行油菜盆栽生物模拟试验,研究了北方石灰性土壤中解磷细菌对磷形态的影响,结果表明:在石灰性土壤中,解磷细菌可以促进Ca2-P、Al-P、Fe-P增加,降低土壤中难溶态Ca10-P、缓效态Ca8-P,对O-P影响不明显,从而证明了解磷细菌能够促进石灰性土壤中磷素形态向易被作物利用状态转化,减缓向缓效态、难溶态的转化。     

施用侧孢短芽孢杆菌对烟草根际微生态及产量和品质的影响

在烟苗大十字期对烟苗根部采取浸根(T1)、灌根(T2)及浸根+灌根(T3)3种方式施用侧孢短芽孢杆菌,分别于移栽后30、60、90 d测定烟草根系活力、土壤微生物种类及其数量、土壤酶活性、烟叶化学品质以及经济性状。结果表明：烟苗移栽后30～60 d,T1、T2、T3的烟草根系活力、土壤酶活性较不施用侧孢短芽孢杆菌均显著提升,T3的烟草根系活力显著提高39.49%,烟草根际土壤细菌和放线菌的数量分别显著增加40.51%、41.64%,真菌数量显著减少28.39%;T1、T2、T3的烟草中部叶常规化学成分均达优质烟叶标准,中上等烟比例及产值较不施用侧孢短芽孢杆菌分别增加19.51%、72.57%,中部叶化学成分较其他处理更趋协调。     

Plant Growth Promoting Traits of Indigenous Phosphate Solubilizing Pseudomonas aeruginosa Isolates from Chilli (Capsicumannuum L.) Rhizosphere

Phosphorus (P) is the second key nutrient for plants and it affects several attributes of plant growth. Identification of a potent phosphate solubilizing microorganism capable of transforming the insoluble P into soluble and plant-accessible forms is considered as the best eco-friendly option for providing inexpensive P to plants. Hence, this study was focused to assess the growth enhancement traits of the phosphate solubilizing bacteria (PSB) isolated from chili rhizosphere. Twelve PSB were isolated by enrichment culture technique and its P solubilization efficiency was checked using Vanadomolybdate phosphoric yellow color method. Among them, two potent strains PS2 and PS3, identified as Pseudomonas aeruginosa KR270346 and KR270347 based on biochemical and molecular characterization, were selected for further study. The Pseudomonas aeruginosa isolates interestingly showed the presence of various potential plant growth-promoting properties including indole acetic acid and siderophore production. The growth enhancement effect of Pseudomonas aeruginosa isolates on chilli showed promising results, and the growth parameters were found to be statistically signi?cant when compared to control. The results demonstrated an eloquent impact on various aspects, namely microbial count and PSB population, phosphatase and dehydrogenase activity, available phosphorous in the soil, plant nutrient uptake, and yield parameters. Inoculation of these two isolates together with the addition of rock phosphate increased comparable amount of available P and these treatments were statistically at par throughout the growth period. The results con?rmed the growth-promoting potential of the isolates to develop as biofertilizers either alone or as components of integrated nutrient management systems.     

秸秆生物质炭对根际土壤细菌-真菌群落分子生态网络的影响

根际细菌-真菌群落的互作关系对于土壤养分转化有重要意义。为研究施加生物质炭对根际土壤细菌-真菌之间相互作用的影响,通过盆栽试验,比较未施加生物质炭的对照和施加2%生物质炭处理条件下,黑麦草根际细菌-真菌群落间的互作网络及影响因素。结果表明,施加生物质炭后的细菌-真菌群落之间的互作网络具有更复杂的联系,节点数和互作关系增加,细菌内部以及细菌与真菌之间的种间积极作用显著增强(P0.05);模块化分析对照和处理下的互作网络,均发现存在两个具有高度互连节点的模块化结构。网络中起到关键连接作用的类群在对照中为细菌中的孙修勤菌(Sunxiuqinia)和真菌中的毕赤酵母(Pichia),施加生物质炭处理后为细菌中的黄杆菌(Flavobacterium)。Mantel检验分析表明,施加生物质炭处理后土壤pH(r=0.385,P=0.003)和土壤铵态氮(r=0.501,P=0.003)对细菌-真菌群落相互作用的影响显著增强。     

Ensiling in 2050: Some challenges and opportunities

Challenges to ensiling are coming from a wide spectrum. Faster harvest rates are making it more difficult to achieve target silage densities. Larger harvest equipment is increasing soil compaction and rural road issues. Older silos are too small and are overfilled, creating safety issues, or temporary piles are placed on bare ground permitting soil contamination. Mycotoxins and other pathogens in silages are still a problem. Global warming may affect the forage crops grown and crop characteristics as well as rates of silage fermentation and aerobic deterioration. Silage as an input to bio‐refineries has an unclear future. Silage analysis is challenged by sampling and knowing what components truly predict nutritional value. The future holds many opportunities for both ensiling and silage research. Robotic harvesting will release more labour for silo packing, and there are opportunities to develop tools to estimate silage density during filling. Total mixed ration silages should allow more by‐products in rations. The development of novel silage additives to improve silage hygiene or increase nutrient availability appears promising. Predicting the onset of aerobic deterioration with quick tests for lactate‐assimilating yeasts or silage temperatures seems possible. Metabolomics and metabonomics, in addition to the microbiome tools in development, put us at the cusp of being able to see which microorganisms are active in the silo and rumen and what compounds of significance they are producing. This could lead to many advances in silage quality including reduced microbial toxins, better hygiene and improved utilization by livestock.     

响应面法优化番茄早疫病拮抗菌WL07发酵条件

应用响应面法对番茄早疫病拮抗菌WL07的培养基组成及培养条件进行优化。通过Plackett-Burman设计试验,从蔗糖、碳酸钙、硫酸铵、硫酸亚铁、酵母膏、装液量、初始pH等影响因素中筛选影响拮抗菌WL07发酵的显著因素。Plackett-Bur-man设计试验结果表明影响拮抗菌WL07发酵的显著因素分别为初始pH和蔗...     

根系分泌物与根际微生物互作的研究进展

根系分泌物是植物与环境进行物质、能量和信息交流的重要载体,与根际微生物具有紧密的互作关系。重点概述了根系分泌物对根际微生物种群、数量、分布和生长发育的影响以及根际微生物对根系分泌物的影响与机制。深入研究根系分泌物和根际微生物是根际生态系统的重要组成部分,微生物非培养新技术的创新与突破将有助于揭示根际微生态规律,挖掘和利用根际功能微生物。