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1.
[目的]研究芽孢杆菌与植物生长调节剂对苔藓结皮生长发育的影响,为提高苔藓结皮种源扩繁效率提供科学依据。[方法]选择芽孢杆菌(胶质芽孢杆菌/巨大芽孢杆菌)与生长调节剂(噻苯隆)2种因素,设计双因素完全试验,观测温室条件下苔藓结皮的覆盖度、株高度和株密度。[结果]①只添加胶质芽孢杆菌处理的苔藓生长状况最优,相比对照组(未添加芽孢杆菌及生长调节剂)分别提高了苔藓覆盖度(+18.9%)、株高度(+0.85 mm)和株密度(+15.44株/cm~2);②添加巨大芽孢杆菌能提高苔藓株密度(+5.76株/cm~2),但会减小其株高度(-0.78 mm),对盖度则无显著影响;③生长调节剂TDZ减小了苔藓植物覆盖度(-11.78%)、株高度(-3.33 mm),对株密度影响不显著;④芽孢杆菌与生长调节剂存在交互作用,巨大芽孢杆菌+TDZ处理增大了苔藓株密度(+9.79株/cm~2),且高于只添加巨大芽孢杆菌处理(+3.67株/cm~2),胶质芽孢杆菌+TDZ处理增加苔藓株密度(+4.3株/cm~2)但弱化了胶质芽孢杆菌的促进作用(-11.14株/cm~2)。[结论]功能性微生物与生长调节剂对苔藓结皮生长发育具有显著影响,在今后苔藓结皮种源扩繁实践中应加以考虑和借鉴。  相似文献   

2.
利用自主分离的芽孢杆菌菌株TS01和15种芽孢杆菌(地衣芽孢杆菌,枯草芽孢杆菌,短小芽孢杆菌,巨大芽孢杆菌,凝结芽孢杆菌,蜡状芽孢杆菌,迟缓芽孢杆菌,苏云金芽孢杆菌,嗜热脂肪芽孢杆菌,解淀粉芽孢杆菌,环状芽孢杆菌,球形芽孢杆菌,侧孢短芽孢杆菌,多粘类芽孢杆菌,泛酸枝芽孢杆菌)模式菌种进行ARDRA分析。采用16S rDNA通用引物16S-27和16S-1525进行PCR扩增,16S rDNA扩增片段经六种限制性酶(Alu I、Taq I、Mse I、Bst UI、Hha I和Tsp509 I)酶切电泳,获得了TS01菌株的特征性ARDRA指纹图谱。ARDRA图谱通过GelcomparⅡ软件进行聚类分析(UPGMA),结果表明菌株TS01和地衣芽孢杆菌处于同一分支,亲缘关系最近。ARDRA分析鉴定结果与实验室前期菌株TS01形态、生化鉴定和16S rDNA序列分析结果一致,TS01是一株地衣芽孢杆菌菌株,从而证明ARDRA技术在菌种水平上对芽孢杆菌TS01进行鉴别具有可靠性。  相似文献   

3.
测定了一株地衣芽孢杆菌YC10发酵液对辣椒疫霉菌的抑制率、菌丝的生长及游动孢子释放和萌发的影响。结果表明,地衣芽孢杆菌YC10发酵液对辣椒疫霉菌具有一定的抑制作用,抑制率达78.67%;可导致病原菌菌丝畸形、分支增多及原生质浓缩;对辣椒疫霉游动孢子释放和萌发的相对抑制率为36.91%和57.14%,与对照相比明显抑制了游动孢子的释放和萌发。  相似文献   

4.
禾谷镰刀菌引起的小麦赤霉病能够导致小麦产量的大幅降低和品质的严重损失。为探索赤霉病生物防治方法,本试验从扬花期被禾谷镰刀菌侵染的麦穗上分离得到28株芽孢杆菌,利用平板对峙法对其进行筛选,其中20株菌对禾谷镰刀菌表现出明显的拮抗作用。根据生理生化特性和16S rDNA序列分析,这20株拮抗菌分别被鉴定为甲基营养型芽孢杆菌(11株)、解淀粉芽孢杆菌(2株)、枯草芽孢杆菌(2株)、暹罗芽孢杆菌(3株)和特基拉芽孢杆菌(2株)。这些菌株能够有效降低小麦赤霉病的发病率、发病程度和病情指数,其中菌株JS62N、JS15E和JS29I能够将赤霉病发病率降低80%以上;菌株JS29I、JS62N、JS39C和JS39D能够将赤霉病发病程度降低80%以上。16株菌能将病情指数降低80%以上;所有菌株均能极显著增加小麦的百粒重,JS12Q效果最好(+101.4%)。本研究结果为小麦赤霉病的防治提供了生物防治材料。  相似文献   

5.
采用多重筛选方法相结合,从土壤、秸秆、堆肥等不同来源样品中分离得到4株具有较强纤维素降解能力细菌A531、A422、B622和C631,该4株菌株同时具有使堆肥快速升温和有效除臭潜力。经菌体形态观察、生理生化分析及16S rDNA鉴定,其中两株分别为蜡状芽孢杆菌(A531)、白色芽孢杆菌(C631),菌株A422和B622须进一步鉴定。将该4株菌与本实验室保藏的1株氨氧化细菌(新型耐热芽孢杆菌Aliibacillus thermotolerans)BM62按照不同比例配制成复合菌剂进行堆肥功能验证,结果表明,菌株A531、A422、B622、C631和BM62按照1∶1∶1∶1∶1的比例混合进行堆肥,与对照堆肥相比,添加菌剂的堆肥中纤维素降解率提高19.83%,总氮损失率降低10%,NO_2~-含量增加46.6%,NH_3挥发率降低35.5%;将此复合菌剂各菌株比例调整为2∶2∶1∶1∶1的堆肥结果为,纤维素降解率提高了21.73%,总氮损失率减少8.1%,NO_2~-含量增加39.7%,NH_3挥发减少23.1%;将此复合菌剂各菌株比例调整为1∶2∶1∶2∶1的堆肥结果为,纤维素降解率提高了18.86%,总氮损失率减少了11.2%,NO_2~-含量增加了49.1%,NH_3挥发减少42.6%。以上结果表明,此复合菌剂可以明显降低堆肥过程不愉快气味,降低堆肥中氮素损失,快速有效分解纤维素等有机物质,具有很好的应用价值和社会意义。  相似文献   

6.
为更好地防治棉花黄萎病,在冀棉11根系中分离得到一株对大丽轮枝菌抗性明显的内生细菌,经分子鉴定为解淀粉芽孢杆菌489-2-2。本试验以489-2-2为材料,研究该菌株对棉花黄萎病的防效和机理。结果表明,解淀粉芽孢杆菌489-2-2能够抑制黄萎病菌Vd080的生长,可导致Vd080菌丝形态异常。用该菌株发酵液浸泡棉花种子,对棉花黄萎病的防效为54.99%,灌根法的防效为60.31%。解淀粉芽孢杆菌489-2-2能使植株产生防御酶,诱导的免疫反应较强,且该菌株能定殖到棉花幼苗根系内部。本研究结果为解淀粉芽孢杆菌489-2-2的利用提供了理论依据。  相似文献   

7.
几株固氮芽孢杆菌的分离与鉴定   总被引:6,自引:0,他引:6  
摘要: 从小麦(Triticum aestivum)、玉米(Zea mays)、黑麦草(Lolium sp.)和柳树(Salix sp.)的根际土壤中分离得到能在无氮培养基上生长的29株芽孢杆菌(Bacilli),通过固氮酶活的测定以及固氮酶结构基因 nifH 的PCR扩增得到7株固氮芽孢杆菌。对这7株固氮菌株进行了生理生化性状测定、16S rDNA序列分析(GenBank accession No. AY373358, AY373360,~AY373364和AY376876)、G+C mol%含量的测定及DNA-DNA杂交实验,结果表明,其中5株菌属于芽孢杆菌,另外2株菌属于类芽孢杆菌。在这7株被鉴定的菌株中,菌株T1被鉴定为Bacillus cereus;菌株G1、C4和C5被鉴定为B. megaterium;菌株W5的生理生化性状、16S rDNA和G+C mol%与Bacillus marisflavi 相近;G2的生理生化性状和16S rDNA 与Paenibacillus polymyxa 接近,但在基于16S rDNA的系统发育树中却与P. durus 聚在最小的分支内;T7可能是Paenibacillus属中的一个新种。  相似文献   

8.
苹果树腐烂病拮抗细菌鉴定及其抑菌作用效果测定   总被引:8,自引:0,他引:8  
为了开发一种高效低毒的苹果树腐烂病生防制剂,通过对峙培养法、形态学及分子生物学的方法进行了苹果树腐烂病菌拮抗菌的分离筛选及鉴定,采用离体枝条法测定了拮抗菌对苹果树腐烂病的防效,并采用显微观察和液体培养法分别研究了拮抗菌对苹果树腐烂病菌的抑菌机理和无菌滤液对苹果树腐烂病菌生长的影响。分离筛选结果表明,从甘肃省各苹果产区果园土壤和苹果树枝条上分离得到23株细菌,2株对苹果树腐烂病菌具有较好拮抗作用,分别为LZ-1201和TS-1203,其对苹果树腐烂病菌菌丝生长抑制率分别为79.00%和85.00%。鉴定结果表明,菌株LZ-1201和TS-1203分别为枯草芽孢杆菌(Bacillus subtilis)和解淀粉芽孢杆菌(Bacillus amyloliquefaciens)。离体枝条防效测定表明,拮抗菌无菌滤液对苹果树腐烂病的防效随着稀释倍数增大而降低,原液防效最高,分别为74.43%和77.07%。抑菌作用机理结果表明,两株拮抗菌均可导致苹果树腐烂病菌丝膨大畸形、原生质浓缩、释放及溶解。拮抗菌无菌滤液对腐烂病菌生长的影响测定结果表明,无菌滤液对腐烂病菌分生孢子萌发和菌丝生长量均有显著抑制作用(P0.05),其无菌滤液稀释40倍时对腐烂病菌分生孢子萌发和菌丝生长量的抑制率均高于60%,表明该拮抗菌具有很好的生防潜力。  相似文献   

9.
从盐碱土中分离的几株硅酸盐细菌的生物学特性初步研究   总被引:15,自引:0,他引:15  
对从北方滨海盐碱土中分离到的几株硅酸盐细菌(室内编号B44、B47、B73、B74、B75),以及对照菌株胶冻样芽孢杆菌(室内编号B0)进行了形态学和生理生化特征研究。这些菌株均为革兰氏阴性大杆菌,周生鞭毛,产芽孢和丰厚的荚膜,菌落透明隆起,粘性强;过氧化氢酶试验阳性,能水解明胶,M.R试验阳性,V.P阴性,不产生吲跺。除对照菌株B0外,都能在pH值为9.0的培养条件下生长,能耐受3%以上的NaC l浓度。  相似文献   

10.
本文报道了胨冻样芽孢杆菌 (Bacillusmucilaginosus)的分离、筛选及其对小麦苗期生长的作用 ,并对胨冻样芽孢杆菌的发酵培养基进行了优化 .结果表明 ,胨冻样芽孢杆菌 (B .mucilaginosus)生长的最适培养基 (g/L)为 :蔗糖 1 4、Na2 HPO4 1 .5、FeCl3 0 .0 0 2、CaCO3 1 .5、酵母膏 1 0 ,自来水 1 0 0 0ml、pH7.0~ 7.5;有机氮和无机铵态氮抑制胨冻样芽孢杆菌的生长 ;胨冻样芽孢杆菌液体培养物对小麦苗期生长具有促进作用 .  相似文献   

11.
In order to select appropriate Bradyrhizobium USDA reference strains for primary grouping of indigenous soybean bradyrhizobia, we systematically constructed phylogenetic trees of 20 USDA strains based on DNA sequence analysis and PCR-restriction fragment length polymorphism (RFLP) targeted to 16S rDNA and the internal transcribed spacer (ITS) region between 16S and 23S rDNAs. The phylogenetic trees of 16S rDNA showed 3 major groups, cluster USDA 110 (USDA 62, 110, 122, 125, and 129), cluster USDA 6 (USDA 4, 6T, 38, 115, 123, 127, 135, and 3622T) and cluster B. elkanii (USDA 31, 46, 61, 76T, 94, and 130), as well as the phylogenetically independent strain USDA 124. The topology of the ITS trees was almost similar to that of 16S rDNA, although the positions of two extra-slow-growing strains, USDA 135 and USDA 3622T were variable among the ITS sequences, PCR-RFLP of the ITS region and 16S rDNA. Only two strains, USDA 110 and USDA 122, harbored hup genes and they fell into the USDA 110 cluster. These results suggest that PCR-RFLP analysis of 16S rDNA and the 16S-23S rDNA ITS region may be useful for the grouping of bradyrhizobia and for the first screening of hup-positive strains. Based on the above results, we propose a minimum set of USDA strains reflecting Bradyrhizobium diversity that includes B. japonicum USDA 6T, B. japonicum USDA 110, B. japonicum USDA 124, and B. elkanii USDA 76T. In addition, an extra-slow-growing strain with the serotype USDA 135 might be necessary for genomic diversity analysis of bradyrhizobia, because their phylogenetic positions were variable.  相似文献   

12.
Bacillus thuringiensis is indistinguishable from Bacillus cereus except for the production of insecticidal crystal proteins (ICPs). B. thuringiensis strains may show enterotoxin profiles and toxin levels similar to those of B. cereus strains isolated from food-poisoning cases. It is important for the food industry and farmers to consider that with the application of B. thuringiensis strains to crops, their spores may be introduced into the human food chain. In this study, 59 B. thuringiensis strains were assayed for their hemolysin BL (HBL) using a BCET-RPLA kit and their cytotoxicity to Chinese hamster ovary (CHO) cells. The enterotoxin titer was as high as that of B. cereus diarrheal-type strain ATCC 49064. In an attempt to obtain a food safety strain for bioinsecticide use, in this study, a 3.5-kb cry1Ac DNA fragment was amplified with PCR from the total DNA of B. thuringiensis subsp. kurstaki CCRC 11502 and cloned into the Bacillus expression vector pHY300PLK. The alpha-amylase promoter, amyE, was then introduced into the promoter region and, afterward, the recombinant plasmid pHYe1Ac35 was introduced into a non-enterotoxigenic and non-cytotoxic B. thuringiensis subsp. kurstaki Tt14 strain. The transformant, without any detectable enterotoxigenicity or cytotoxicity, produced Cry1Ac toxin properly, and its insecticidal activity against Trichoplusia ni larvae was found to be satisfactory.  相似文献   

13.
Jatropha (Jatropha curcas L.) is a non-edible oil-seed plant with adaptability to marginal semi-arid lands and wastelands. The Indian Government is promoting jatropha to reduce dependence on the crude oil and to achieve energy independence by the year 2012, under the National Biodiesel Mission. Selected strains of Bacillus spp., either supplemented with or without chitin, were tested for their ability to promote growth of jatropha seedlings in pot culture studies. The strains supported growth of jatropha seedlings up to 42 days after sowing. Among all strains, Bacillus pumilus (IM-3) supplemented with chitin showed over all plant growth promotion effect resulting in enhanced shoot length (113%), dry shoot mass (360%), dry root mass (467%), dry total plant mass (346%), leaf area (256%), and chlorophyll content (74%) over control. Treating seeds with strain IM-3 without chitin resulted in enhanced dry shoot mass (473%), dry total plant mass (407%), and chlorophyll content (82%). However, Bacillus polymyxa (KRU-22) with chitin supported maximum root length (143%). Either strain IM-3 alone or in combination with other promising strains could be promoted further for enhanced initial seedling growth of jatropha.  相似文献   

14.
Summary Bacteria isolated from the root zones of field-grown soybean plants [Glycine max (L.) Merr.] were examined in a series of glasshouse experiments for an ability to affect nodulation competition among three strains of Bradyrhizobium japonicum (USDA 31, USDA 110, and USDA 123). Inocula applied at planting contained competing strains of B. japonicum with or without one of eleven isolates of rhizosphere bacteria. Tap-root nodules were harvested 28 days after planting, and nodule occupancies were determined for the bradyrhizobia strains originally applied. Under conditions of low iron availability, five isolates (four Pseudomonas spp. plus one Serratia sp.) caused significant changes in nodule occupancy relative to the corresponding control which was not inoculated with rhizosphere bacteria. During subsequent glasshouse experiments designed to verify and further characterize these effects, three fluorescent Pseudomonas spp. consistently altered nodulation competition among certain combinations of bradyrhizobia strains when the rooting medium did not contain added iron. This alteration typically reflected enhanced nodulation by USDA 110. Two of these isolates produced similar, although less pronounced, effects when ferric hydroxide was added to the rooting medium. The results suggest that certain rhizosphere bacteria, particularly fluorescent Pseudomonas spp., can affect nodulation competition among strains of R. japonicum. An additional implication is that iron availability may be an important factor modifying interactions involving the soybean plant, B. japonicum, and associated microorganisms in the host rhizosphere.Paper No. 10648 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7601, USA  相似文献   

15.
枯草芽孢杆菌(Bacillus subtilis)SO113对水稻白叶枯病菌(Xanthomonas oryzaepv.oryzae)有强烈的抑菌作用(表现出一透明抑菌圈)。培养液上清中加入60%饱和度的硫酸铵沉淀所得的蛋白粗提液对热稳定,对链霉蛋白酶E不敏感,对蛋白酶K部分敏感,对中国各稻区白叶枯病菌的7种致病型都有强烈的抑杀作用,蛋白粗提液100℃加热15min后脱盐,经DEAE0-Sepharose Fast Flow柱层析得3个未分开的抗菌活性峰,示吸附部分经CM-Sepharose Fast Flow柱层析,得到1个主活性峰,由于B.subtilis SO113的分泌蛋白对水稻白叶枯病菌表现出良好的广谱抗性以及丰富的抗菌活性峰,因此对其进一步的研究和设法隆编码抗菌蛋白的基因都具有重要意义。  相似文献   

16.
本文对33株枯草芽孢杆菌群菌株进行β-甘露聚糖酶活性筛选,其中的32株具有β-甘露聚糖酶活性,只有1株无β-甘露聚糖酶活性。通过基因克隆测序的方法获得33株枯草芽孢杆菌群菌株β-甘露聚糖酶基因编码区全序列,对酶基因进行同源性分析并构建系统发育树;在β-甘露聚糖酶基因系统发育树中,33株枯草芽孢杆菌群菌株聚为3个分支,分别是枯草芽孢杆菌分支、地衣芽孢杆菌分支和解淀粉芽孢杆菌分支;枯草芽孢杆菌、地衣芽孢杆菌和解淀粉芽孢杆菌β-甘露聚糖酶基因种内同源性大于91%,而种间同源性为60%~69%。  相似文献   

17.
我国大豆种植区使用人工选育制成的根瘤菌剂接种效果不稳定。研究指出南方、北方和黄淮流域的6个省土壤中分布的主要Bradrhizobium.japonicum是DH444、USDA110、LL120、005和C224血清型的菌株,主要的Rhizobium.fredii是2048、USDA217、DE1611、2120和2077血清型的菌株。它们占每个取样地点分离物总数的60.3-81.6%。植物感染结瘤法测得大豆种植地点土著根瘤菌菌数在104/克土以上。盆栽试验表明大豆根瘤菌与大豆品种共生时有较强的亲和选择性和共生效应的多样性,其有效结瘤和固氮效率与根瘤菌个体菌株和大豆品种极相关。大多数土著大豆根瘤菌是低或中效固氮的菌株,因而认为选育抗土著根瘤菌而有利于人工接种菌株结瘤的大豆品种和强竞争性的高效菌株仍是提高我国大豆生产的有效途径。  相似文献   

18.
In 2009 a greenhouse experiment was conducted to determine the effects of boron (B) and plant growth-promoting rhizobacteria (PGPR) on wheat (Triticum aestivum spp. vulgare cv ‘Bezostiya’) and barley (Hordeum vulgare cv ‘Tokak’) on plant growth, freezing injury, and antioxidant enzyme capacity. Results showed that boron (0, 1, 3, 6, 9 kg B ha?1) and PGPR application (Bacillus megaterium M3, Bacillus subtilis OSU142, Azospirillum brasilense Sp245 and Raoultella terrigena) at which 50% of leaves were injured (LT50) values and ice nucleation activities in both plants were found statistically significant. Boron application with all PGPR strains decreased LT50 values in wheat and barley plants under noncold stress (NCS) and cold stress conditions (CS). There were statistically significant differences between bacterial inoculation and B fertilizer in terms of root and shoot dry weight under NCS and CS conditions. Reactive oxidative oxygen species (ROS) and antioxidant enzyme activities (SOD, POD, CAT) were negatively affected CS conditions and decreased with reduced temperatures of media, but B and PGPR applications alleviated the low-temperature deleterious effects in both plants species tested. The lowest ROS and antioxidant enzyme (SOD, POD, CAT) of wheat and barley were observed with 6 kg B ha?1 with R. terrigena.  相似文献   

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