马铃薯内生细菌的分离及其对环腐病菌的拮抗作用检测（简报）

马铃薯是世界四大作物之一,我国是世界上马铃薯种植面积最大的国家,种植面积达6000万亩。近年来,在马铃薯经济良好发展的带动下,马铃薯生产在种植面积和单产水平上有了大幅度提高。然而各种病害随之表现出逐年上升的趋势。     

农杆菌转化马铃薯与抗病毒基因工程

马铃薯是目前世界上主要粮食作物之一,其产量仅排在小麦、玉米和水稻之后,占第四位。马铃薯既可用作粮食又可用作蔬菜,具有生育期短、高产、适应性强和营养丰富的特点。但马铃薯的产量和质量仍然受许多因素的限制,其中病害是最明显的。这些病害包括晚疫(Phytophthora infestance)、环腐(Corynebacterium sepedonium)、黑胫     

具有防止细菌侵染功能的自杀反应

美国Ｃｏｌｏｒａｄｏ州立大学的科研人员发现了植物防御革兰氏阳性菌（已知为棒状细菌）侵染的证据。抗病机理类似于其自身抗其他细菌侵染的机理。此项发现将最终导致开发出广谱抗病的遗传工程作物。研究焦点是引发马铃薯环腐病的细菌。在马铃薯地里一株表现环腐病的马铃...     

玉米种质和新品种对腐霉茎腐病和镰孢穗腐病的抗性分析

玉米是我国最重要的农作物之一,腐霉茎腐病和镰孢穗腐病是玉米生产上的重要病害。2006-2012年期间,对1647份玉米种质进行了抗肿囊腐霉茎腐病和拟轮枝镰孢穗腐病鉴定,筛选出高抗茎腐病和穗腐病的种质分别为564份和27份,占鉴定总材料的34.2%和1.6%,抗性材料分别为209份和352份,占比为12.7%和21.4%,表明高抗肿囊腐霉茎腐病的资源较为丰富,高抗镰孢穗腐病的种质相对匮乏。其中,13份种质对2种病害均表现高抗,207份种质对2种病害均表现抗性或对其中一种表现高抗而另一种表现抗性。自交系中对肿囊腐霉茎腐病和拟轮枝镰孢穗腐病表现抗性以上(含HR和R)的种质分别占总鉴定种质的56.5%和23.6%,在农家种中分别为21.2%和21.4%,表明玉米自交系中的抗性资源较农家种丰富。2009-2013年期间参加国家玉米区试的品种中,对腐霉茎腐病表现高抗、抗性、中抗、感病和高感的品种分别占11.5%、11.9%、40.1%、17.6%和18.9%。2009-2011年间,中抗以上的育成品种所占比例呈现明显上升趋势,但2012-2013年间,中抗以上的品种所占比例呈下降趋势。     

芒果、香蕉采后病害生物防治的研究进展

芒果、香蕉采后主要病害为炭疽病、蒂腐病、冠腐病、黑腐病、黑星病.生物防治是当前芒果、香蕉采后病害控制的重要研究方向.概述了生物防治芒果、香蕉采后病害的方法,包括诱抗剂、植物提取物、拮抗微生物在芒果、香蕉采后病害防治上的研究与应用.     

香荚兰根腐病的研究Ⅱ.病害发生规律

香荚兰根腐病是香荚兰(Vanilla frangrans)的严重病害之一。据报道^[4-6]世界上许多产区的香荚兰根腐病均为Fusarium oxysporum f.sp.vanillae(tucker) Gordon所致。已经证实,厦门地区室内种植的香荚兰根腐病亦为该菌所致^[1],为害严重。国外许多文献^[2-7]报道过本病,但对其发生规律尚缺乏系统研究。在我国也未见报道。本文所报是作者近年来在这方面研究的结果。     

葡萄上两个真菌性病害

报道了葡萄上两个国内新记录真菌病害:由茶子小穴壳菌(Dothiorella ribis)引起的熟腐病和败育假蜜环菌(Armillariella tabescens)引起的根腐病。病害附有症状和病原菌的描述和形态图。     

凤梨小果芯腐病病原菌凤梨镰孢菌在中国的首次发现

近年,在广东徐闻凤梨种植基地生产的凤梨果实在采后贮藏过程中发生一种果肉腐烂病害,发病率达10%左右,并有逐年加重危害的趋势。为了明确该病的病原菌,本文通过果实组织分离和接种试验获得1个致病菌株,通过形态学观察和TEF-1α序列分析,确定该病的病原菌为凤梨镰孢菌Fusarium ananatum,这是该菌所致凤梨小果芯腐病在国内的首次报道。     

基于高精度转录组测序技术挖掘甘蔗抗梢腐病相关的NBS-LRR家族基因

甘蔗(Saccharum officinarum)是中国乃至世界第一大糖料作物,也是非常重要的生物能源作物。甘蔗在大田生长过程中经常遭遇病原菌侵入而诱发甘蔗病害,严重时会造成产量下降、品质受损,在广西蔗区常年大面积种植甘蔗,梢腐病的发生极为普遍,也常因此造成严重的经济损失。本研究以具有易感梢腐病特征的现代栽培种‘中蔗1号’为实验材料,采用一种更高精度的转录组测序新技术,在全基因组水平鉴定到含有NB-ARC结构域的NBS抗病基因(含等位基因)共2 324个,其中在‘中蔗1号’梢腐病病株与健康蔗株中存在差异表达的基因有101个。进一步对这些基因的结构域进行注释分析,确定了36个NBS-LRR类抗病基因。推测这些基因可能参与甘蔗对梢腐病致病菌的抵御以及病害侵染甘蔗后的一系列防御反应。     

玉米茎腐病研究进展

茎腐病是国内外玉米生产中的重要病害之一,近年来,随着机械收获和籽粒直收,茎腐病已成为玉米生产中最具威胁性的病害,利用抗病品种是防治玉米茎腐病最为经济、有效的措施。因此,本文从茎腐病的发生与为害、病原菌种类、抗茎腐病种质资源筛选、抗性遗传和抗病基因发掘与定位等几个方面阐述了国内外玉米茎腐病的研究进展,旨在为该病害的综合治理奠定重要的理论基础。     

防治马铃薯环腐病有益内生细菌的分离和筛选

1998～2000年,从大同、太原和内蒙古自治区等地采集健康块茎中分离到133株内生细菌,通过离体抑菌作用测定、田间和温室实验,初步筛选出5个具有促生或潜在防治马铃薯环腐病的内生细菌,其中118菌株定殖、促生和拮抗三种作用兼备,具有很好的开发应用前景。     

甘蔗赤腐病内生拮抗菌YC89的筛选及鉴定

【目的】筛选防治甘蔗赤腐病(sugarcane red rot)的生防菌株。【方法】实验以前期分离获得的甘蔗内生细菌为目标菌,以甘蔗赤腐病的病原真菌镰孢炭疽菌(Colletotrichum falcatum Went.)为指示菌,采用平板对峙法筛选对该病菌有较强抑制作用的菌株,然后通过琼脂扩散法测定菌株代谢产物对抑菌活性的影响,并对具有较好拮抗效果的高效菌株进行抑菌广谱性分析并对其进行鉴定。最后通过形态学、生理生化特征以及16SrDNA和gyrA序列分析对高效菌株YC89进行鉴定。【结果】经初筛筛选到抑菌带均大于1.60 cm的5株拮抗细菌,其中X22、W2、YC89抑菌带均高达1.87 cm。对初筛得到的5株内生菌进行复筛,结果所示菌株YC89、H1、X22、W2、YT93对镰孢炭疽菌的抑菌率都在75%以上,其中菌株YC89对该病菌的抑菌效果最好,其抑菌率为78%。菌株YC89的发酵液、上清液、过滤液及粗蛋白提取液对镰孢炭疽菌的生长有较强的抑制作用,且菌株YC89对玉米大斑病、甘蔗梢腐病、草莓灰霉病等7种病原菌也有较好的抑制效果。通过菌株鉴定结果,初步将YC89菌株鉴定为贝莱斯芽孢杆...     

Endophytic bacterial flora in root and stem tissues of black pepper (Piper nigrum L.) genotype: isolation, identification and evaluation against Phytophthora capsici

Aim:  To isolate and identify black pepper ( Piper nigrum L) associated endophytic bacteria antagonistic to Phytophthora capsici causing foot rot disease.
Methods and Results:  Endophytic bacteria (74) were isolated, characterized and evaluated against P. capsici . Six genera belong to Pseudomonas spp (20 strains), Serratia (1 strain), Bacillus spp. (22 strains), Arthrobacter spp. (15 strains), Micrococcus spp. (7 strains), Curtobacterium sp. (1 strain) and eight unidentified strains were isolated from internal tissues of root and stem. Three isolates, IISRBP 35, IISRBP 25 and IISRBP 17 were found effective for Phytophthora suppression in multilevel screening assays which recorded over 70% disease suppression in green house trials. A species closest match (99% similarity) of IISRBP 35 was established as Pseudomonas aeruginosa ( Pseudomonas EF568931), IISRBP 25 as P. putida ( Pseudomonas EF568932), and IISRBP 17 as Bacillus megaterium ( B. megaterium EU071712) based on 16S rDNA sequencing.
Conclusion:  Black pepper associated P. aeruginosa , P. putida and B. megaterium were identified as effective antagonistic endophytes for biological control of Phytophthora foot rot in black pepper.
Significance and Impact of the Study:  This work provides the first evidence for endophytic bacterial diversity in black pepper stem and roots, with biocontrol potential against P. capsici infection.     

地锦草内生细菌多样性、拮抗及促生特性测定

【背景】植物内生细菌既能抑制病原菌对植物的侵染,也具有促生作用。分离具有拮抗和促生活性的内生细菌可为开发微生物菌肥提供理论依据。【目的】筛选内生细菌中的优势拮抗、促生菌种资源。【方法】以地锦草为材料,采用4种分离培养基分离该植物内生细菌,通过形态特征以及16S r RNA基因序列分析,鉴定内生细菌的分类归属。采用平板对峙法,测定内生细菌对棉花立枯丝核菌(Rhizoctonia solani)、小麦赤霉病菌(Fusarium graminearum)、玉米小斑病菌(Bipolaris maydis)的拮抗活性。通过固氮、解磷、产吲哚乙酸(Indole Acetic Acid,IAA)、产铁载体能力等指标初步检测地锦草内生细菌的促生活性。【结果】共分离到133株内生细菌,分属于4门5纲8目13科25属,其中变形菌门(Proteobacteria)为优势门(52.63%),优势属为芽孢杆菌属(Bacillus),占15.79%。发现有8株菌相似性小于98.65%,可能为潜在新物种。拮抗活性结果表明,22株菌有不同程度的抑菌作用,其中菌株DHL56、DHN17、DHP3、DHP8对这3种病原菌...     

一株马铃薯干腐病拮抗菌的筛选、鉴定及其生物防效

【背景】马铃薯干腐病是一种由镰刀菌引起的田间和储藏期都普遍发生的病害,主要引起块茎腐烂,致使马铃薯品质和产量降低,严重影响其食用价值和经济价值。【目的】发掘有效的生防菌株以控制马铃薯干腐病,并探究其抑菌作用。【方法】从甘肃定西地区马铃薯根际土壤中分离到109株细菌,以硫色镰刀菌(Fusarium sulphureum)为靶标菌,采用平板对峙法筛选拮抗菌,并通过形态学、生理生化特征及16S r RNA基因序列分析对拮抗菌株进行鉴定。检测拮抗菌无菌发酵液对F.sulphureum菌丝生长、孢子萌发、马铃薯块茎损伤接种病斑直径、干腐病发病率及对绿豆种子发芽的影响。【结果】筛选到一株对马铃薯干腐病有较强抑制作用的菌株YL11,经鉴定其为假单胞菌属(Pseudomonas sp.)菌株。YL11菌株无菌发酵液对F.sulphureum菌丝生长、孢子萌发、马铃薯块茎病斑扩展、干腐病发病率、毒素活性均有显著抑制作用。20%无菌发酵液对F.sulphureum菌落生长的抑制率达到87.3%;75%无菌发酵液可完全抑制孢子萌发;无菌发酵液浸泡能有效抑制马铃薯干腐病病斑的扩展,14 d时对病斑扩展的抑制率达到67.1%;90 d后干腐病的发生率降低了68.4%;同时降低了F.sulphureum毒素的活性。【结论】拮抗菌株YL11能显著抑制F.sulphureum的生长,对马铃薯干腐病有较强的生物防治效果,具有潜在的应用价值。     

沙棘根瘤内生细菌中抑菌促生菌株的筛选和鉴定

【背景】植物内生细菌可产生具有抑菌和促生活性的物质,既能抑制植物病原菌对寄主植物的侵染,也能促进植物的生长。沙棘根瘤内生细菌是根瘤内除共生固氮的弗兰克氏菌外,与沙棘共生的一大类微生物。研究具有抑菌和促生活性的植物内生菌,可为微生物菌肥的研究提供理论基础。【目的】筛选具有优良抑菌和促生活性的沙棘根瘤内生细菌,初步研究其抑菌和促生活性,并对菌株进行鉴定。【方法】采用双层琼脂法、琼脂扩散法、双层平板对峙法、牛津杯法进行沙棘根瘤拮抗性内生细菌的筛选。选取抑菌活性较高的内生细菌,分别采用Salkowski比色法、ChromeAzurolS(CAS)平板检测法和钼锑抗比色法进行产吲哚乙酸、铁载体及溶磷能力的测定。采用发酵液灌根法测定沙棘根瘤内生细菌SR308对黄瓜促生作用的盆栽效果。通过形态和培养特征、生理生化试验及16S rRNA基因序列分析法对菌株TT201和SR308进行鉴定。【结果】从131株沙棘根瘤内生细菌中筛选出9株具有较强抑菌活性的内生细菌,其中菌株TT201抑菌性最佳、抑菌谱广;菌株SR308的促生活性最好,其发酵液对黄瓜的生长具有较强的促进作用。对具有较强抑菌和促生活性的菌株TT201和SR308进行鉴定的结果表明,菌株TT201为侧孢短芽孢杆菌(Brevibacilluslaterosporus),菌株SR308为蕈状芽孢杆菌(Bacillusmycoides)。【结论】获得2株具有优良抑菌和促生活性的沙棘根瘤内生细菌,为进一步开发微生物农药及菌肥提供了资源。     

Analysis of pectate lyases produced by soft rot bacteria associated with spoilage of vegetables.

Isoelectric focusing (IEF) profiles of pectate lyases (PLs) produced by five different groups of soft rot bacteria were analyzed by using the combined techniques of thin-layer polyacrylamide gel IEF and agarose-pectate overlay activity staining. Four strains of soft rot Erwinia spp. produced three or more PL isozymes. All of eight Pseudomonas viridiflava strains examined produced one single PL with a pI of 9.7. All 10 of Pseudomonas fluorescens strains produced two PLs; the major one had a pI of 10.0 and the minor one had a pI of 6.7. A single PL with a pI of greater than or equal to 10.0 was detected in one strain each of Xanthomonas campestris and Cytophaga johnsonae. PLs of six representative strains were purified from culture supernatants by ammonium sulfate precipitation and anion-exchange chromatography. All purified PL samples macerated potato slices, but to different degrees. The Mrs of alkaline PLs produced by P. viridiflava, P. fluorescens, X. campestris, and C. johnsonae were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 42,000, 41,000, 41,500, and 35,000, respectively. IEF profiles of PLs were distinct among the bacterial species. Profiles of non-Erwinia spoilage bacteria were considerably simpler than those of Erwinia spp. The PL with an alkaline pI appeared to be the principal or the sole enzymatic factor involved in tissue maceration caused by most strains of soft rot bacteria.     

Biological control of Tiarosporella phaseolina the causal agent of charcoal rot of soybean

Charcoal rot caused by Tiarosporella phaseolina (Tassi) Van der Aa is an important disease of soybean in Gorgan province of Iran. Experiments were carried out with 95 bactenal isolates that were collected from the rhizosphere of soybean plant. Among these bacteria only 50 isolates showed antagonistic effect on Tiarosporella phaseolina using dual culture test. Six highly effective bacteria were selected for subsequent studies. Based on biochemical physiological and morphological tests, isolates Pf-12 and Pf-63 were identified as Pseudomonas fluorescens, isolates B-13, B-42,B-126 and B-84 as Bacillus subtilis. The isolates of P. fluorescens produced antibiotics as well as volatile metabolites that inhibited mycelial growth of fungus. Bacillus subtilis isolates inhibited the fungal growth through volatile and non-volatile metabolites production. Only P. fluorescens isolates produced hydrogen cyanide. In greenhouse studies, the isolates B-13 and B-126 reduced 59% and 66% the intensity of charcoal rot of soybean respectively. The combinations of isolates B-13 and B-126 were also effective on reducing the intensity of disease.     

Analysis of pectate lyases produced by soft rot bacteria associated with spoilage of vegetables

Isoelectric focusing (IEF) profiles of pectate lyases (PLs) produced by five different groups of soft rot bacteria were analyzed by using the combined techniques of thin-layer polyacrylamide gel IEF and agarose-pectate overlay activity staining. Four strains of soft rot Erwinia spp. produced three or more PL isozymes. All of eight Pseudomonas viridiflava strains examined produced one single PL with a pI of 9.7. All 10 of Pseudomonas fluorescens strains produced two PLs; the major one had a pI of 10.0 and the minor one had a pI of 6.7. A single PL with a pI of greater than or equal to 10.0 was detected in one strain each of Xanthomonas campestris and Cytophaga johnsonae. PLs of six representative strains were purified from culture supernatants by ammonium sulfate precipitation and anion-exchange chromatography. All purified PL samples macerated potato slices, but to different degrees. The Mrs of alkaline PLs produced by P. viridiflava, P. fluorescens, X. campestris, and C. johnsonae were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 42,000, 41,000, 41,500, and 35,000, respectively. IEF profiles of PLs were distinct among the bacterial species. Profiles of non-Erwinia spoilage bacteria were considerably simpler than those of Erwinia spp. The PL with an alkaline pI appeared to be the principal or the sole enzymatic factor involved in tissue maceration caused by most strains of soft rot bacteria.