免疫捕捉PCR和经典PCR方法检测水稻细菌性谷枯病菌灵敏性比较

将免疫吸附富集(ISE)和经典PCR结合以提高水稻细菌性谷枯病的检测效率,并且利用多克隆抗体技术成功地获得了4种抗血清,即抗Burkholderia glumae全菌体血清ASBg14,ASBg32,ASBg26和ASBg04,ODD法测定该4种抗血清的效价均达到1∶32以上,利用凝聚法测定的所有抗血清的效价也均达到了1∶5 120 以上,通过两种方法结合测定效价均显示为合格抗体。通过对4种抗血清的专化性进行研究,结果显示ASBg14和ASBg32专化性较高,抗血清ASBg26 和ASBg04专化性不是很理想。用直接PCR技术和免疫捕捉PCR技术检测谷枯病菌,结果表明,所有谷枯病菌都能产生500 bp左右的特异性片段,非谷枯病菌的8个菌株均无特异性片段产生。两种检测方法的灵敏度比较发现,直接PCR技术能检测到1×105 cfu·mL-1左右的悬浮液,免疫捕捉PCR技术能检测到103 cfu·mL-1 左右悬浮液,免疫捕捉PCR比直接PCR灵敏性提高102倍。检测人工接种的病稻种实验中,直接PCR技术能检测到2粒及以上带菌种子制得浸悬液,而免疫捕捉PCR技术仅1粒带菌种子即可。     

水稻病原菌Burkholderia plantarii群体感应和群体淬灭研究进展

植物伯克霍尔德菌Burkholderia plantarii是引起水稻秧苗细菌性立枯病的重要病原菌之一,其侵染性、繁殖力及适应性均很强,严重威胁中国水稻生产。文章围绕B.plantarii的发生、危害及致病机理,着重论述了细菌群体感应系统(quorum sensing,QS)的生理功能及其在B.plantarii致病力调控方面的最新研究进展,并进一步从根际微生物互作角度,综述了种间信号分子对病原菌群体淬灭(quorum quenching)的作用机制,同时结合种间信号分子的独特性,展望了其在新型微生物杀菌剂研发中的重要性和应用潜力。     

Management of bakanae and bacterial seedling blight diseases in nurseries by irradiating rice seeds with atmospheric plasma

The control of seedborne rice seedling diseases in the seed beds is important to avoid epidemics in rice nurseries and paddies, which may result in severe yield loss. Recently, irradiation with plasma containing electrons, creating positive or negative ions and neutral species, has been shown to have an antimicrobial effect, probably via generation of reactive oxygen species. This study examines whether two seedborne rice seedling diseases, bakanae disease caused by the fungal pathogen Fusarium fujikuroi, and bacterial seedling blight caused by Burkholderia plantarii, are suppressed by irradiation of infected rice seeds with atmospheric plasma. Seed germination and seedling growth were not inhibited in plasma‐treated healthy seeds. When F. fujikuroi‐infected rice seeds were irradiated with plasma after being immersed in sterile distilled water, bakanae disease severity index and the percentage of plants with symptoms were reduced to 18.1% and 7.8% of non‐irradiated control, respectively, depending on the duration of plasma irradiation. The bacterial seedling blight disease index was also reduced by plasma irradiation in vacuum‐inoculated seeds to 38.6% of the non‐irradiated control, and in infected seeds harvested from spray‐inoculated heads of rice plants to 40.1% of the control. Therefore, plasma irradiation seems to be effective in controlling two independent seedborne rice seedling diseases.     

吡咯伯克霍尔德氏菌JK-SH007的发酵条件及其对杨树溃疡病的防治效果

本文研究了拮抗细菌吡咯伯克霍尔德氏菌Burkholderia pyrrocinia菌株JK-SH007产抗菌物质的最佳发酵条件及其对杨树溃疡病的野外防治效果。结果表明,牛肉膏、蛋白胨是发酵培养基中最佳营养物质,有利于菌株JK-SH007抗菌物质的产生;培养基初始pH、培养时间、温度、培养体积、不同牛肉膏、蛋白胨组合等对菌株生长及其抗菌物质的产生有明显的影响,初始pH7、牛肉膏2g、蛋白胨20g、以1/2装液量装液、30℃振荡培养36h可获得较高产量的胞外分泌型抗菌物质;菌株JK-SH007的发酵液对杨树溃疡病的野外防效可达40.54%。     

洋葱伯克氏菌群不同基因型菌株对几种重要植物病原真菌的抑制作用及其潜在致病性

从玉米和水稻根围分离到70株不同基因型的洋葱伯克氏菌,对这些菌株进行了拮抗植物病原菌的筛选,并对高拮抗菌株进行了潜在致病性和安全性分析。结果表明,有46株洋葱伯克氏菌对一种或多种病菌有较高的拮抗活性。在不同的洋葱伯克氏菌基因型内,以基因型Ⅴ内拮抗菌株占的比例最高,对所测5种病原真菌的平均拮抗菌株比率为80．0％,其中部分菌株表现出很强的拮抗活性。筛选出的4株高拮抗菌株对洋葱不具有致病性,同时也未检测到与人体致病相关的BCESM毒力基因。     

Effect of N2‐fixing bacterial inoculations on yield of sugar beet and barley

Drawbacks of intensive farming practices and environmental costs of N fertilizers have renewed interest in bio‐fertilizers. This study was conducted in order to investigate the effectiveness of 7 N₂‐fixing bacterial isolates from various sources in sugar beet and barley production under field conditions in the higland plateau of Erzurum, Turkey (29° 55′ N and 41° 16′ E with an altitude of 1950 m) in 1999 and 2000. Seeds were inoculated with five bacterial strains of Bacillus; BA‐140, BA‐142, M‐3, M‐13, and M‐58, a strain of Burkholderia (BA‐7) and Pseudomonas (BA‐8). The bacterial strains had been demonstrated to grow in N‐free basal medium. The experiment also included applications of mineral nitrogen (N), phosphorous (P), and NP‐fertilizer as well as a control treatment without inoculation and fertilizer application. Two years of trials under field conditions showed that seed inoculation with bacterial strains significantly affected yield, yield components, and quality parameters both in sugar beet and barley. On an average of both years, seed inoculation of sugar beet with BA‐140, BA‐142, M‐58, BA‐7, BA‐8, M‐13, and M‐3 increased root yield by 13.0, 12.6, 10.5, 9.2, 8.1, 6.1, and 6.5% as compared to the control and sugar yield by 7.8, 6.3, 5.1, 4.0, 3.2, 2.3, and 5.3%, respectively. N, P, and NP applications, however, increased root yield up to 13.6, 5.3, and 21.4% and sugar yield by 6.1, 4.0, and 14.8%, respectively. Of the bacteria tested, BA‐140 and BA‐142 had yields equal to N application. All bacterial inoculations also gave higher seed and total biomass yields in barley than control plots. BA‐140 and BA‐142 were top yielding strains. In conclusion, bacterial seed inoculations especially with BA‐140 and BA‐142 may satisfy nitrogen requirements of sugar beet and barley under field conditions even in upland areas.     

洋葱伯克氏菌群的多样性

洋葱伯克氏菌是一组表型相近、但基因型不同的细菌群。本文综述了洋葱伯克氏菌群的生物学功能、基因型种类和特征、基因型的鉴定技术进展以及我国洋葱伯克氏菌基因型的研究现状。     

Burkholderia属luxIR同源群体感应系统的研究进展

介绍了群体感应系统和Burkholderia属概况,阐述了Burkhkolderia菌属中的群体感应系统,并展望了其应用前景。     

洋葱伯克氏菌群的多样性

洋葱伯克氏菌是一组表型相近、但基因型不同的细菌群。该菌对人类有利有弊,在农业和医学领域表现出多种多样的功能,研究洋葱伯克氏菌基因型种类和生物学功能的相关性对于全面认识该微生物具有重要的理论和应用价值。综述了洋葱伯克氏菌群的生物学功能、基因型种类和特征、基因型的鉴定技术进展以及中国洋葱伯克氏菌基因型的研究现状,并对洋葱伯克氏菌群的未来发展进行了展望。     

Characterization and Identification of Two Opportunistic Human Bacterial Pathogens in Rice

Rice plant harbors numerous prokaryotes in which some are pathogenic, some are beneficial with promoting growth of plant or antagonistic against pathogens, and most of them are “neutral” ones with unknown functions. The earliest report on rice bacterial diseases was recorded more than 120 years ago [1]. Over 20 bacterial species were reported to be associated with the rice diseases [2-3]. Recently environmental protectionists are paying more attention to control the release of toxic chemical…