营养添加剂对枯草芽孢杆菌G3 str在土壤中繁殖及其抑菌物质分泌能力的影响

从生防菌G3菌株筛选到的抗链霉素自然突变株G3^str,保持G3原有的抑菌活性,产伊枯草菌素和生物表面活性素,能抑制多种植物病原真菌.25℃下,营养添加剂对G3^str菌在不灭菌土壤中前5d有一定的增殖作用;10d后G3^str菌在土壤中主要以芽孢的形态存活;60d后,G3^str菌在土壤中仍以106cfu/g水平存活.G3^str菌在土壤中增殖时分泌少量的伊枯草菌素,但被快速分解;同时分泌较多的生物表面活性素,营养添加剂的加入明显促进其分泌.     

溴甲烷土壤熏蒸处理，植物促生菌对大田黄瓜病害的生物防治作用

有人发现，植物生长促生菌（PGPR）能诱导黄瓜产生诱发系统抗性。为了进一步研究植物生长促生菌在有或无溴甲烷土壤熏蒸情况下对黄瓜生长及其自然发生的病害的作用，我们于1996年－1997年进行了田间试验，试验设7个植物生长促生菌的种子处理，其中包括枯草芽孢杆菌（Bacillus punilus)INR7,萎蔫短小杆菌（Curtolxacteriun flaccunfaciens)ME1和枯草芽孢杆菌（Bacillus punilus)GBO33个菌株的单菌株处理及其4个混合菌株的处理。两年的数据表明，在无溴甲烷（MeBr)土壤熏蒸的情况下，所有7个植物生长促生菌处理与空白对照组相比都能显著促进黄瓜植株生长；而在有溴甲烷熏蒸的情况下，同样7个植物生长促生菌试验处理中，1996年有3个处理而1997年只有1个处理显著促进植株生长。1996年试验结果表明，7种植物生长促生菌处理中，有或无溴甲烷熏蒸处理黄瓜主茎生长长度的结果均相似。两年的田间试验表明，有或无溴甲烷的熏蒸；7种植物生长促生菌处理与空白对照相比都能显著减轻黄瓜叶病的严重度。1996年自然发生的叶病是黄瓜角斑病（Pseudomonas syringae pv.lachrymans)，1997年出现的是炭疽病菌（Colletotrichum orbiculare)和角斑病的复合侵染现象。两年中，无论是有还是无溴甲烷熏蒸的情况下，植物生长促生菌菌株的混合物处理比单个菌株处理表现出较高的抗病作用。结果表明，植物生长促生菌诱导蔬菜产生的诱发系统抗性作为蔬菜病虫害综合防治中的一个措施，不应该受到从现有蔬菜生产技术标准中逐步取消溴甲烷而产一的负面影响，植物生长促生菌的促生作用能补偿在无溴甲烷土壤熏蒸处理下造成的植株生长减少。     

枯草芽孢杆菌B_3菌株对小麦根系和茎基部的定殖作用研究

本文研究了枯草芽孢杆菌Ｂ＿３菌株经种子处理后在小麦根系及茎基部的定殖能力和影响其定殖的可能因子。结果表明，Ｂ＿３在田间自然土壤中定殖小麦根系及茎基部的时间分别为６０天和４２天以上。培养不同时间的Ｂ＿３菌悬液处理种子表明，播后２２天内，培养２４小时的菌在小麦上的定殖量高于培养４８和７２小时。用ＮＢ培养的Ｂ＿３菌悬液经离心弃上清，并用新鲜ＮＢ液悬浮菌体后处理种子，在播后１９天，Ｂ＿３定殖量比不处理菌悬液的定殖量增加。Ｂ＿３与化学杀菌剂混合处理种子，以及土壤经灭菌处理均可增加Ｂ＿３在小麦上的定殖量。     

荧光假单胞菌CZ菌株定殖及抗病毒活性研究

荧光假单胞菌Pseudomonas fluorescens CZ能分泌包括碱性磷酸酶在内的抗病毒蛋白抑制烟草花叶病毒Tobacco mosaic virus(TMV)侵染?本文利用抗生素利福平逐级诱导获得抗药性标记菌株CZ-rif, 生测试验显示:野生型和抗药型菌株的发酵上清和粗蛋白液对TMV的体外钝化效果均大于90%, 无显著差异?灭菌和非灭菌的根际土拌CZ-rif菌液后盆栽烟苗, 取根际土在含抗生素的平板上检测定殖菌量, 结果显示, CZ-rif能够在烟株根际土壤中有效定殖, 第31天在灭菌土中的定殖菌量为4.3×104 cfu/g, 显著大于在非灭菌土中的定殖菌量6×103 cfu/g, 在叶面上的定殖菌量显著低于根际土壤?叶面喷施CZ-rif菌液后24 h接种病毒, 对TMV-GFP的预防效果为45.85%?田间试验中喷淋菌株发酵稀释液, 对烟草花叶病毒病的防效为42.02%?此外, 水培试验显示生防菌发酵液对烟草幼苗具有促生作用?总之, 荧光假单胞菌CZ能在烟草根际定殖和促进植株生长, 叶面喷施能钝化TMV并抑制其初侵染, 可以研发防治病毒病害的生物制剂?     

二甲基二硫的生物活性评价及对土壤养分的影响

采用室内生物活性测定方法,评价二甲基二硫(dimethyl disulfide,DMDS)对土壤病原线虫和土传病原菌的毒力,比较不同浓度药剂处理对土壤理化性质和土壤呼吸的影响,为探究DMDS作为新型土壤熏蒸剂提供切实可行性的依据。结果表明:DMDS熏蒸对土传病原线虫和镰刀菌属的LD_(50)分别为4.743 mg/kg和1.513 mg/kg,可见DMDS对病原线虫和镰刀菌有良好的生物活性。对土壤理化性质进行数据分析发现:DMDS能显著增加土壤铵态氮含量,抑制硝化作用过程,减少NO~-_3-N的产生,提高植物可吸收态氮素水平。DMDS处理的土壤有机质含量和电导率均显著高于对照土壤,而土壤pH和速效钾含量较对照均有降低。此外,熏蒸土壤中有效磷含量较对照减少,但两者无显著差异。对DMDS熏蒸后土壤进行底物诱导呼吸试验,表明DMDS能够在试验初期抑制土壤微生物生物量。本试验结果可为指导DMDS的科学使用提供理论依据及对土壤微生物活性的影响作出科学评价。     

土壤不同处理对木霉菌定殖及其生防效果的影响

重茬土经施肥改土、高温灭菌后,增施木霉菌的试验结果表明:木霉菌可以在甜瓜根表、根际定殖存活,同时不影响其他有益微生物的正常生长;土壤经高温灭菌后,土壤中的微生物呈真空状态,有利于木霉菌的快速定殖,促进甜瓜生长,降低甜瓜枯萎病的病情指数。甜瓜枯萎病发病率与土壤中镰刀菌孢子的存活量成正相关,与土壤中木霉菌、细菌数量的多少成负相关。     

内生黏质沙雷氏菌LIEH 92对向日葵菌核病的防治效果及其防病机制研究

本研究评价了从向日葵列当体内分离筛选得到的内生黏质沙雷氏菌(Serratia marcescens)LIEH 92对向日葵菌核病进行盆栽与大田防效评价,并测定了该菌株的生理特性和其在根际土与向日葵体内的定殖情况。结果表明,LIEH 92发酵液对向日葵菌核病的室内盆栽防效达73.35%,对大田根腐型菌核病和盘腐型菌核病防效分别达53.48%和38.64%。菌株LIEH 92可产生几丁质酶,并能在根际土和向日葵根、茎、叶内定殖与传导,定殖菌量达102~106 cfu/g。其在向日葵植株的根内定殖数量最大,茎中次之,叶中最少。在灭菌土中LIEH 92在根际土和向日葵根部的定殖菌量小于在自然土中其在相应部位的定殖菌量,而灭菌土中LIEH 92在向日葵茎部和叶部的定殖菌量则大于自然土中相应的定殖菌量。LIEH 92处理可提高向日葵植株PAL、POD和PPO等防御酶活性,从而诱导向日葵对菌核病的抗性。LIEH 92对向日葵菌核病具有生防潜力。     

根肿病生防菌Zhihengliuella aestuarii B18定殖能力及防效分析

Zhihengliuella aestuarii B18是一株对十字花科根肿病菌Plasmodiophora brassicae具有抑制作用的优良生防菌株。为探明其生防潜能,本文通过抗生素抗性标记法、盆栽试验和田间小区试验研究了B18在不同土壤pH、土壤温度、土壤含水量、初始接种浓度、蔬菜作物以及不同土壤类型中的定殖动态。灭菌土试验结果表明:调节土壤pH 7.5～8.5,含水量10%～30%,放置于10～25℃,70 d后B18定殖菌量保持在105～107 cfu/g。盆栽试验结果表明:初始接种菌液浓度为109 cfu/mL时,45 d后根际土中定殖菌量可稳定在104～105cfu/g。将50 mL浓度为2×109 cfu/mL的生防菌菌液接种于田间不同类型土壤后,第30天定殖菌量分别为病田8.7×105cfu/g,病土1.02×105cfu/g,健田8.5×104cfu/g,健土2.6×104cfu/g,即定殖能力由强到弱依次为:病田＞病土＞健田＞健土。且病田中B18在根际土中可存活至45 d且菌量保持在104 cfu/g,根内可存活至31 d且菌量保持在104 cfu/g。田间调查结果显示B18在病田和病土中对榨菜根肿病的防效分别为42.01%和47.53%,增产率分别为37.24%和40.22%。     

土壤熏蒸与水肥菌/药一体化技术联用防控设施番茄病害

为了减少设施番茄生产中农药化肥的使用,集成了土壤熏蒸及水肥菌/药一体化技术,并在湖北十堰开展了设施番茄病害的综合防控试验示范。试验设置3个处理,分别为CK(不做土壤熏蒸+水肥药常规化管理)、T1(土壤熏蒸+水肥药常规化管理)、T2(土壤熏蒸+水肥药一体化管理)。田间试验结果表明:采用土壤熏蒸可使番茄的根结线虫病降低70.7%~75.0%,灰霉病、早疫病和青枯病的综合发病率降低33.0%~63.7%,产量增加25.0%左右;土壤熏蒸结合水肥菌/药一体化技术可使番茄的根结线虫病降低 82.7%~85.1%,灰霉病、早疫病和青枯病的综合发病率降低70.2%~74.0%,产量增加35.9%~41.0%。相对于常规管理措施,采用水肥菌/药一体化技术可以节约灌溉用水18.8%、节约用肥33.3%、节约用药21.3%。上述结果表明:土壤熏蒸消毒结合使用水肥菌/药一体化产品和技术,可以节水、节肥、节药,显著降低设施番茄各类病害的发生,提高番茄产量,实现节本增效。     

育苗基质中添加不同微生物菌剂对烟草抗病性及产质量的影响

土传病害给烟草的产质量造成严重损失,而在大田施用生物菌剂进行生物防治往往因生防菌剂在土壤中适应增殖困难而效果不理想.本研究采用基质拌菌的方法,选取4种常用拮抗微生物菌剂(枯草芽孢杆菌菌剂、荧光假单胞杆菌菌剂、解淀粉芽孢杆菌菌剂和多粘类芽孢杆菌菌剂),探究不同微生物菌剂早期根际定殖对烟草青枯病的防控效果及对烟株农艺性状和产量的影响.结果表明:在育苗基质中加入微生物菌剂可以优化烟草苗期和团棵期农艺性状,提高烟草对青枯病的抗病性,其中以培育1 000株烟苗的育苗基质中加入多粘类芽孢杆菌500g(有效芽孢量5×10~3亿cfu)效果最好.本试验结果为育苗基质拌菌技术在烟草促生和抗病方面提供理论支撑.     

The effects of soil solarization and soil fumigation on Fusarium wilt of watermelon grown in plastic house in south-eastern Spain

The effects of pre-planting solarization or fumigation with metham-sodium of sand-mulched soil on fusarium wilt of watermelon in plastic house culture were investigated at Almeria, south-eastern Spain. In two trials, 2 months' solarization increased the average maximum soil temperature by c. 5°C to 44-48° C at 10 cm depth and by 4-5° C to 40-42° C at 20-30 cm. The amount of Fusarium oxysporum in the upper 15 cm of a naturally infested soil was reduced by solarization and by fumigation. During the 9 months following treatment, the F. oxysporum population stabilized at a low level in soil solarized for 2 months, but fluctuated in soil solarized for 1 month and increased in fumigated soil. The amount of wilt in watermelon sown into this soil after treatment was generally low; plants growing in solarized or fumigated soil suffered less wilt than plants in untreated soil but the differences were not significant. In a soil artificially infested with the highly pathogenic race 2 of F. oxysporum f. sp. niveum, F. oxysporum populations were greatly reduced following solarization or fumigation, and fluctuated erratically thereafter. Solarization for 2 months completely controlled wilt in watermelon and gave a fruit yield almost five times that of plants in untreated soil. Solarization for 1 month only slowed disease development slightly but gave a yield more than twice that in untreated soil. Fumigation with metham-sodium retarded disease development considerably and tripled fruit yield. Plant performance was significantly better in soil solarized for 2 months than in uninfested control soil, suggesting beneficial effects of this treatment additional to wilt control.     

土壤熏蒸剂棉隆联合太阳能消毒防治草莓土传病害效果及经济效益分析

太阳能消毒技术在世界范围内广泛使用, 由于其经常受到气候差异的影响导致效果不稳定, 通常与其他措施结合以加强防治效果。种植前采用土壤熏蒸是土传病害的有效预防策略, 本研究通过监测土壤温度、理化性质、土传病原菌、草莓植株长势、产量和分析经济效益, 评价了不同浓度的土壤熏蒸剂棉隆和太阳能消毒联合处理对草莓土传病害的防治效果及经济效益分析。种植前棉隆熏蒸和太阳能消毒处理不仅能很好地控制土传病害, 其对镰刀菌属、疫霉属的抑制率分别为64.41%~84.75%、51.59%~86.94%, 而且显著提高了草莓的产量, 增产率为79.9%~99.4%;联合处理的成本较单独太阳能消毒处理仅增加约3.29%~13.17%, 但净收入增长率高达49.77%~66.28%。因此, 在草莓土传病害管理中, 土壤熏蒸与太阳能消毒处理相结合, 可以降低作物感染土传病害的风险, 保证作物稳定高产。     

Fumigation of citrus fruit with ethylene dibromide: Desorption of residues and ethylene evolution

The desorption of ethylene dibromide (EDB) residues from fumigated Shamouti citrus fruits is fitted by a single exponential equation at 17 and 22°C, and by an equation with a double exponential term at 5°C. Establishing the rate constant enables calculation of the initial concentration of EDB residues in the peel, thereby obtaining information on conditions during fumigation and on the possibility of peel injury development in the fumigated fruit. Healthy, harvested Shamouti citrus fruit evolve ethylene at a low rate, which is increased by EDB fumigation. Fumigated fruit in which EDB caused peel injury evolved ethylene at a higher rate than fumigated fruit in which peel injuries did not develop. This information could be used for predicting peel injuries and in studies aimed at a better understanding of the processes leading to the development of peel injuries in fumigated citrus fruit.     

Response of different intermediate-day onion hybrids to natural infestation by Phoma terrestris and Fusarium oxysporum f. sp. cepae in Ciudad Real, Spain with assessment of different soil disinfestation methods

Incidence and severity of Pink root caused by Phoma terrestris and Fusarium basal rot caused by Fusarium oxysporum f. sp. cepae were field-tested on factorial combinations of different soil fumigation treatments in five different intermediate-day onion hybrids widely adapted at the Bola?os de Calatrava area (Ciudad Real, Spain). The effect of Dazomet and virulence of the local isolates were then tested in trays under greenhouse conditions. When compared to Electric, the other four onion hybrids showed a certain degree of tolerance to Pink root and Fusarium basal rot with little difference among them. The field trial carried out in 2006 showed significant but negligible beneficial effects in medium bulb weight and Pink root severity due to Dazomet. The field trial carried out in 2007 showed significant beneficial effects of Metham-sodium on plant growth and Pink root and Fusarium basal rot severities. Sodium tetrathiocarbonate performed worse than the control. Greenhouse test showed that Dazomet performed nearly as well as sterilization under controlled conditions. Virulence of local isolates was lower than that of reference isolates.     

低剂量棉隆熏蒸联合生物菌肥防治黄瓜根结线虫病的应用效果

为明确土壤熏蒸联合生物菌肥对根结线虫及土壤微生态的影响,采用低剂量棉隆熏蒸处理后沟施YB-04菌肥的方法在日光大棚进行黄瓜根结线虫病的防治试验。结果显示,棉隆熏蒸联合YB-04菌肥沟施处理土壤中的根结线虫数和黄瓜植株根系的根结指数均比单独使用棉隆或YB-04菌肥的处理及对照显著降低,黄瓜移栽后90 d时线虫减退率为89.1%,根结指数为0.5,防治效果达87.8%。棉隆熏蒸联合YB-04菌肥沟施处理也具有显著的促生作用,黄瓜的产量、株高、鲜重以及有效叶数均比对照显著提高了46.4%、18.8%、63.0%和17.7%。另外,棉隆单独熏蒸处理土壤中的细菌和真菌数量、细菌/真菌比值及土壤酶活性均较对照显著降低,而棉隆熏蒸联合YB-04菌肥沟施处理土壤中的细菌数量、细菌/真菌比值及土壤酶活性均较棉隆单独熏蒸处理显著增加,其中,细菌数量及细菌/真菌比值分别达28.4×106CFU/g和201.2,蔗糖酶活性达86.0 mg·g~(-1)·24 h~(-1)。表明低剂量棉隆熏蒸联合YB-04菌肥沟施可以安全高效地防治黄瓜根结线虫病。     

Biological Control Efficiency of Fusarium Wilt of Tomato by Nonpathogenic Fusarium oxysporum Fo-B2 in Different Environments

ABSTRACT Efficiency of nonpathogenic Fusarium oxysporum Fo-B2 for the biological control of Fusarium wilt of tomato, caused by F. oxysporum f. sp. lycopersici CU1, was examined in different environments: a growth chamber with sterile soil-less medium, a greenhouse with fumigated or nonfumigated soil, and nonfumigated field plots. Inoculation of Fo-B2 onto tomato roots significantly reduced the severity of disease, but the efficiency of disease suppression decreased as the experimental environment became less controlled. Relationships between the recovery of Fo-B2 from hypocotyls and the disease severity indicated that the biocontrol agent was most effective when it colonized vascular tissues intensively. Moreover, the degree of Fo-B2 colonization was greatly reduced when the seedlings were grown in nonfumigated soil. Dose-response models (negative exponential, hyperbolic saturation, and logistic) were fit to observed data collected over a range of inoculum densities of the pathogen and the antagonist; the logistic model provided the best fit in all environments. The ratios of an 50% effective dose parameter for Fo-B2 to that of CU1 increased as the environment became less controlled, suggesting that environmentally related efficiency reduction impacted the antagonist more than the pathogen. The results suggest that indigenous soil microbes were a primary factor negatively influencing the efficiency of Fo-B2. Therefore, early establishment of the antagonist in a noncompetitive environment prior to outplanting could improve the efficacy of biological control.     

我国土壤熏蒸消毒60年回顾

熏蒸剂棉隆和氯化苦于20世纪60年代在我国曾用于棉花黄萎病的防治,由于缺乏施药机械、相关施药标准和方法,加之与国外交流甚少,虽然发现熏蒸剂对土传病害有一定的效果,但一直未形成规模化应用。我国大量使用熏蒸剂进行土壤消毒处理始于20世纪90年代,随着溴甲烷的引进与广泛应用,溴甲烷的替代技术及产品研发,开启了我国土壤熏蒸消毒的新纪元。伴随着土壤消毒技术与理论的不断丰富,新型配套机械装备的成功研发,社会化服务模式的广泛运用,土壤熏蒸消毒在我国进入快速发展时期,大批专业化服务组织应运而生,为我国农作物病虫害的绿色防控、实施乡村振兴战略提供了强有力的技术支撑。该文从土壤熏蒸剂的种类、发展历史、基础理论的建立与阐明3方面综述了我国土壤熏蒸发展情况,并对我国土壤熏蒸消毒未来发展方向提出了展望。     

磷化氢熏蒸南洋臀纹粉蚧的效果及对火龙果品质的影响

本文在25℃条件下,利用磷化氢熏蒸南洋臀纹粉蚧以及越南进口红心、白心火龙果4 h,研究了磷化氢熏蒸处理对南洋臀纹粉蚧的杀灭效果以及对火龙果采后储藏品质的影响。耐受性比较试验结果表明,不同发育阶段的南洋臀纹粉蚧对磷化氢的耐受性为雌成虫>3龄若虫=2龄若虫>1龄若虫。毒力分析试验表明,使用1.70 mg/L磷化氢熏蒸雌成虫4 h可在95%置信区间下达到99.996 8%的死亡率。品质试验结果表明,使用0.55～2.21 mg/L磷化氢熏蒸处理对两种火龙果冷藏和货架期间的色泽、硬度、可溶性糖、酸度均无显著影响,但在熏蒸后短期内会提高呼吸强度,随着储存时间延长,呼吸强度恢复正常。这些结果显示,磷化氢熏蒸用于进口火龙果携带南洋臀纹粉蚧的检疫处理可达到理想效果,在25℃使用1.66～2.21 mg/L磷化氢熏蒸4 h可作为口岸检疫熏蒸的技术指标。