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1.
烟草内生短短芽孢杆菌的分离鉴定及对烟草青枯病的防效 总被引：5，自引：0，他引：5
在烟草青枯病区采取健康烟草植株,从其茎杆内分离到2株对烟草青枯拉尔氏菌(Ralstonia solanacarum)有强拮抗作用的内生菌株009和011。形态观察、生理生化鉴定及16S rDNA序列比对结果表明,菌株009和011均归属为Brevi-bacillus brevis,009、011菌株与B. brevis(AY591911)相似性分别为99.5%和99.0%,GenBank登录号分别为DQ444284、DQ444285。生长特性研究结果表明,它们的最适生长pH值分别为6.5、7.5,最适生长温度分别为25、30℃。温室内用淋根法分别先接种009和011菌株,后接种病原菌,其防效分别为87.25%和52.30%。用009和011菌液分别和烟草青枯病菌的混合液淋根,其防效明显低于前者。田间小区试验结果表明,011菌株的防效明显高于009菌株和农用链霉素。 相似文献
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烟草青枯病生防细菌的筛选与生防效果研究 总被引：2，自引：0，他引：2
从云南文山烟草种植田烟草植株根围土壤及植株根内生境中分离纯化获得195株细菌,以细菌菌株对青枯雷尔氏菌（Ralstonia solanacearum）YN10的拮抗作用及其产蛋白酶、几丁质酶、纤维素酶和产嗜铁素的活性作为评价指标对其生防潜力进行赋值,对总赋值得分较高的84株菌株做了聚类分析,选择25株拮抗细菌进行了烟草青枯病温室防效试验。结果表明,聚类分析ARDRA图谱中位于不同组的25株拮抗细菌对烟草青枯病都有不同程度的防治效果,菌株K-1-8、R-3-16、R-3-18的温室防效分别为86.66%、84.94%、87.57%;拮抗细菌的生防效果与总赋值存在正相关,相关系数达0.86。 相似文献
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烟草青枯病内生拮抗细菌的鉴定及小区防效的初步测定 总被引：16，自引：0，他引：16
烟草青枯病是由青枯雷尔菌(Ralstonia solanacearum)引起的一种以土壤传播为主的细菌性病害.目前对该病的防治主要以化学手段为主,但长期大量施用化学农药易产生抗药性和造成环境污染,因此生物防治受到国内外研究者的广泛重视.内生细菌可系统地在植物体内定殖,生存环境较为稳定,是一类潜在的重要生防菌资源.我们从烟草茎杆中分离到160株内生菌株,在室内进行了对青枯病拮抗作用的测定,选择拮抗效果较好的菌株进行了小区防效试验. 相似文献
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为明确烟草青枯病菌在根际的定殖情况和最适发病条件,采用绿色荧光蛋白(gfp)标记病原菌,监测其在根际的定殖位置及数量动态变化,并运用荧光定量PCR法测定病原菌在根际和土体土壤的数量,通过响应曲面法探索病原菌致病的临界浓度、发病最适温湿度以及对烟株青枯病发病的影响。结果表明,从贵州省烟田土壤中分离到烟草青枯病病原菌茄科劳尔氏菌Ralstonia solanacearum,gfp-标记的茄科尔劳尔氏菌主要定殖于根尖和根毛区,少数菌落定殖于初生根的延长区,定殖部分表现为非连续性;第10、15、20天根际土壤的茄科劳尔氏菌数量均显著高于土体土壤数量,分别是土体土壤中的1.15、1.33、1.42倍;当土壤中每克土病原菌数量为106.82 CFU、温度为30.55℃、相对湿度为81.42%以上时,烟草青枯病的病情指数最高为91.13,烟株易发生青枯病。表明茄科尔劳尔氏菌在根际土壤中比土体土壤更易定殖,烟草青枯病发病条件主要取决于病原菌浓度、温度以及相对湿度3项指标。 相似文献
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内生菌B47的定殖能力及其对番茄青枯病的防治作用 总被引：11，自引：4，他引：11
从番茄茎分离的内生枯草芽孢杆菌菌株B47对番茄青枯病有较好的防治作用,利用该菌株的抗链霉素突变菌株,研究其在土壤和番茄植株根、茎中的定殖能力及其对番茄青枯病的防治作用。结果表明,枯草芽孢杆菌菌株B47可在土壤和番茄植株中定殖。B47施到土壤中后的15~45天,其数量逐步增加,45天后,其数量逐步下降。B47在土壤中的定殖能力随土壤的种类和土壤的处理情况而异。施入菜地土后的第45天,B47在非灭菌土中的数量是9.91×105cfu/g土壤干重,而在灭菌土中的数量是9.84×107cfu/g土壤干重。接种后,番茄植株根和茎中的B47数量,从苗期到结果期逐渐增加,但到了成熟期呈下降趋势。B47和番茄青枯病菌混合施入土壤后,随B47的数量增加番茄青枯病菌的数量显著降低。当番茄植株根和茎中B47的含量分别为1.17×104cfu/g鲜重和3.33×104cfu/g鲜重时,接种番茄青枯病菌后的第20天,对番茄青枯病的防治效果达79.79%。 相似文献
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为获得对烟草黑胫病和根黑腐病具有双重防病效果且能够促进烟草生长的假单胞杆菌,采用稀释涂布法从40份土壤样品中分离出201株细菌,通过平板对峙和含毒介质法,筛选出对烟草黑胫病和烟草根黑腐病病原菌均具有良好拮抗作用的菌株PA2101和PG3402。盆栽促生试验表明,菌株PA2101和PG3402能协调地改善烟草地上部分的生长和烟草根系发育,均在一定程度上增加了烟草的株高、叶面积、株鲜重、根鲜重、叶片数和根长,提高了烟草的根冠比和根活力。盆栽试验结果表明,菌株PA2101对烟草黑胫病和根黑腐病的防效分别为70.11%和62.67%,均高于其对照药剂;菌株PG3402对两种病害的防效分别为60.92%和60.00%,与对照药剂相当。抗性标记菌株的定殖试验结果表明,菌株PA2101和PG3402在接种后第29 d能定殖于烟草根际土壤和根内,在烟草茎和叶内也能长时间存在,表明两菌株能够良好定殖。16Sr DNA序列、菌落形态和生理生化性状分析表明,菌株PA2101为铜绿假单胞杆菌Pseudomonas aeruginosa,菌株PG3402为格拉纳达假单胞杆菌Pseudomonas granadensis。综上所述,菌株PA2101和PG3402对烟草具有良好的促生作用,并对烟草黑胫病和根黑腐病有较好的防病效果,是具有生防潜力的菌株。 相似文献
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烟草青枯病生防菌混合接种对其定殖及防效的影响 总被引：3，自引：0，他引：3
本研究将枯草芽孢杆菌Bacillus subtilis B001、短短芽孢杆菌Brevibacillus brevis B011和侧孢芽孢杆菌Bacillus laterosporus 2-Q-9混合接种,探讨其协同防治烟草青枯病的有效性和可行性。平板拮抗试验表明,3株生防菌相互间无拮抗作用,且混合菌群的抑菌活性有所增强。定殖试验中,生防菌两两混接总体上可提升其定殖力,但3株混接对B011和2-Q-9有抑制作用;在烟株接种移栽后第60d,各混接组合的定殖总量均达到最大,其中B001＋B011和B011＋2-Q-9组合分别达7.28、7.23lg.cfu/g,远高于其它处理。小区试验表明,3株生防菌不论单用还是混用,其防治效果均优于72%农用链霉素;两菌混接优于对应的单菌处理,其中以B011＋2-Q-9组合防效最好,达83.39%,其次是B001＋B011组合,防效为78.34%;但三株混接的防效仅为45.49%,低于所有生防菌处理。 相似文献
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青枯雷尔氏菌无致病力突变菌株的构建及其防效评价模型分析 总被引：2，自引：0，他引：2
利用青枯雷尔氏菌(Ralstonia solanacearum)无致病力菌株防治番茄青枯病具有很好的应用潜力。作者通过分离筛选自然弱毒株、60Co辐射诱变和EZ-Tn5插入诱变,分别获得3、12和40株青枯雷尔氏菌无致病力突变菌株。经盆栽番茄苗致病性检测,15 d后均未发病,证实均为无致病力青枯雷尔氏菌。进一步对番茄青枯病的防治试验表明,从番茄青枯病发病田块分离的无致病力突变菌株FJAT1458的防治效果最好,防效达100%。该菌株能定殖番茄植株根系土壤、根部和茎部,定殖数量均表现为“先增后减”的趋势,并且接种浓度越大、苗龄越小,定殖数量越大。从构建的防效模型可以看出,不同接种浓度条件下,植株发病率随时间变化符合的回归方程不同,相关系数R值也不同,接种浓度越大,R值越小。本研究获得的青枯雷尔氏菌无致病力突变菌株FJAT1458对番茄青枯病具有很好的防病效果。 相似文献
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Effects of avirulent bacteriocin-producing strains of Pseudomonas solanacearum on the control of bacterial wilt of tobacco 总被引：5，自引：0，他引：5
Root systems of tobacco dipped in suspensions containing 2 × 109 colony forming units (CFU)/ml of avirulent bacteriocin-producing strains (ABPS) of Pseudomonas solanacearum and assayed immediately after planting in steam-sterilized soil had 8 × 106 CFU/root system of ABPS. The bacterial population declined to an average of 5·3 × 105 CFU/root system after 30 days. Roots of seedlings dipped in bacterial suspensions of ABPS were more effectively protected against wilt caused by P. solanacearum than those dipped in suspensions of an avirulent nonbacteriocin-producing strain (ANBPS). Lipopolysaccharide (LPS) isolated from one ABPS (121) inhibited the attachment of bacteria on roots by 70% but had no effect on the reduction of wilt, whereas bacterial cells significantly reduced the disease severity as compared to LPS or water treatment. In steam-sterilized soil containing a 1:1 mixture (5 × 105 CFU/g of oven-dried soil) of ABPS 121 or 237 and the virulent strain K-60, ABPS 121 reduced multiplication of the virulent strain in soil and in the rhizosphere of seedlings. When roots of seedlings were dipped in a suspension of 2 × 109 CFU/ml of ABPS before planting, root colonization by the virulent strain added to steam-sterilized soil at 2 × 106 CFU/g of oven-dried soil was significantly reduced. When roots were dipped in a suspension of ABPS and assayed 20 days after planting, 98% of the bacterial population was found in the original zone of inoculation and only 2% was detected in new growths of the root system. Plants which were grown in soil infested with ABPS 121 or K-60 had both strains present at variable populations along all sections of roots. 相似文献
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抗青枯病转多肽抗生素基因烟草的选育 总被引：2，自引：0，他引：2
分别于温室和田间条件下,对转单价apidaecin、shiva-I及双价apidaecin+shiva-I基因的14个烟草株系材料的T1和T2后代群体进行青枯病抗性筛选鉴定及农艺性状评价。温室盆栽试验中,于5~6叶龄期采用伤根法进行接种。接种后15天,转apidaecin、shiva-I和apidaecin+shiva-I基因烟草的病情指数较对照分别下降了16.3%、15.2%和59.7%。田间自然病圃筛选鉴定结果表明:B43-5-4、B43-5-1、B43-5-2、B43-5-3和B43-4-1等5个株系材料病情指数较起始品种K326降低21%~70%,且农艺性状与起始品种K326无显著差异。 相似文献
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ABSTRACT Strains of Ralstonia solanacearum have been shown to cause bacterial wilt in some, but not all, ecotypes of Arabidopsis thaliana. We demonstrate here that after inoculation of the leaves of resistant ecotype S96 with R. solanacearum strain Ps95 necrosis around the inoculation site rapidly appeared and no further symptoms developed in the plant. Leaves of susceptible ecotype N913 completely wilted 7 days after inoculation with Ps95, and symptoms spread systemically throughout the whole plant within 2 weeks after inoculation. These results suggest that the resistance of Arabidopsis S96 to R. solanacearum is due to a response similar to the hypersensitive response (HR) observed in other plant diseases. Northern blot analysis of the expression of defense-related genes, known to be differentially induced during the HR in Arabidopsis, indicated that pathogenesis-related protein PR-1, glutathione S-transferase (GST1), and Cu, Zn superoxide dismutase (SOD) mRNAs increased significantly in S96 leaves between 3 to 12 h after infiltration with Ps95. The induction of these genes in susceptible ecotype N913 by Ps95 was clearly delayed. Genetic analysis of crosses between resistant ecotype S96 and susceptible ecotype N913 indicated that resistance to Ps95 is due to a single dominant locus. 相似文献
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番茄枯萎病和青枯病拮抗细菌的筛选、评价与鉴定 总被引：2，自引：0，他引：2
从宁夏银川、江苏沭阳和福建厦门的番茄、辣椒、西瓜等作物根际土壤中,分离纯化获得367株细菌菌株。以番茄枯萎病菌Fusarium oxysporum f.sp.lycopersici和番茄青枯病菌Ralstonia solanacearum为靶标菌,从367株菌株中筛选出对两种病菌皆具有很强拮抗作用的菌株22株。拮抗细菌抑菌物质的研究结果表明：22株拮抗细菌均能分泌蛋白酶;不能分泌几丁质酶;3株细菌能分泌纤维素酶;3株细菌能分泌嗜铁素。盆栽试验结果表明：拮抗细菌PTS-394对番茄枯萎病和青枯病的防效最高,分别为77.4%和80%;菌株H-70、L-1和SJ-280对番茄枯萎病和青枯病的防效均大于60%。对上述4株拮抗细菌进行16S rRNA种属鉴定,均为枯草芽孢杆菌Bacillus subtilis。 相似文献
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Ralstonia solanacearum strain OE1-1 causes bacterial wilt on tobacco plants. The popA -mutant 31b, derived from OE1-1 by insertion of transposon Tn 4431 , did not cause wilt on tobacco plants inoculated through the roots. However, when 31b was directly inoculated into xylem vessels, the tobacco plants wilted, similarly to those inoculated with OE1-1. 31b retained its exopolysaccharide productivity and its type-III secretion function. Furthermore, 31b grew in intercellular spaces and systemically infected tobacco plants, similarly to OE1-1. popA consists of an operon with popB and popC , and suppression of popB and popC expression resulting from polar mutation by transposon insertion did not affect the virulence of 31b. The mutated popA ( popA31b ) was composed of 960 nucleotides, including 39 derived from Tn 4431. A recombinant mutant from OE1-1, where popA31b was introduced by marker exchange, showed the same phenotype as 31b. PopA31b protein was extracellularly secreted by 31b co-cultured with Arabidopsis thaliana . These results suggest that PopA31b extracellularly secreted by 31b in intercellular spaces may be implicated in suppression of disease development, leading to inability of the bacteria to induce wilt on plants. Taken together, interactions between host plants and R. solanacearum existing in intercellular spaces immediately after invasion may be involved in disease development. 相似文献
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福建及贵州等地烟草青枯菌系统发育分析 总被引：3，自引：0，他引：3
[目的]探寻烟草上青枯菌的系统发育.[方法]采用演化型分类框架对福建及贵州等地的62个烟草青枯病菌株进行鉴定分析.[结果]基于内切葡聚糖酶基因系统发育学的分析结果表明:所有参试菌株均归属于青枯菌亚洲分支的4个序列变种,分别为序列变种15、17、34和44;尚未发现归属于美洲或非洲分支的烟草青枯病菌株.其中序列变种15和17为优势菌系,序列变种34的菌株都来自福建省,只发现3个菌株属于序列变种44.基于avrA基因的氨基酸序列比对结果表明4个序列变种的avrA基因都属于RS1000类型.[结论]本研究表明福建及贵州等地烟草上的青枯菌存在一定的遗传分化. 相似文献
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枯草芽孢杆菌SB1的抑菌活性及其对番茄青枯病的防治作用 总被引：4，自引：0，他引：4
Bacillus subtilis strain SB1 isolated from tomato roots was evaluated for its ability to control tomato bacterial wilt under greenhouse conditions.Application of strain SB1 culture suspension suppressed tomato wilt disease both in sterilized and non-sterilized soil,providing 76.03% and 77.78% protection,respectively.Wilt symptom was significantly reduced when strain SB1 was applied before pathogen inoculation,while less suppression was conferred by strain SB1 application after pathogen inoculati... 相似文献