一株菜豆普通细菌性疫病拮抗细菌的分离鉴定及其生防效果

菜豆普通细菌性疫病是黑龙江省近年来发生面积较广的菜豆病害之一,严重时可导致菜豆大面积减产,并影响籽粒品质。为发掘菜豆普通细菌性疫病的生防菌资源,本研究从健康菜豆根际土壤中分离筛选到一株对菜豆普通细菌性疫病菌具有显著抑制效果的拮抗菌株B2。经菌落形态观察、生理生化测试、16SrDNA和gyr B基因序列分析,将其鉴定为贝莱斯芽胞杆菌Bacillusvelezensis,该菌株在平板试验中对菜豆普通细菌性疫病病原菌Xanthomonas axonopodis pv. phaseoli(Xap)和Xanthomonas fuscans subsp.fuscans(Xff)的抑菌圈直径分别为19.3和21.8mm。在室内盆栽试验中,菌株B2对Xap和Xff的防效分别为55.42%和67.77%。通过菜豆叶片防御酶活性及丙二醛含量测定显示,菌株B2能显著提高菜豆叶片中SOD、POD、CAT、PPO酶活性,降低丙二醛含量,表明菌株B2能诱导植物防御反应起到抵抗病原菌的作用。综上,菌株B2在由Xap和Xff两种病原菌引起的菜豆普通细菌性疫病生物防治中具有良好的开发应用潜力。     

进境菜豆种子中普通细菌性疫病菌的分离和鉴定

对经甘肃口岸进境的30批菜豆Phaseolus vulgaris种子进行了普通细菌性疫病菌的检测,利用选择性培养基MT从波兰进境菜豆种子上分离到1株细菌597,对该分离物进行菌落形态特征观察、致病性测定、16S rDNA及16S-23S rDNA ITS序列分析和特异性PCR检测。结果表明,该分离物在MT培养基上菌落呈黄色、圆形、黏稠、表面光滑向外隆起、菌落周围有水解圈。分离物597接种菜豆幼苗后导致叶片枯萎,接种点干枯。结合菌落形态、16S-23S rDNA ITS序列、特异性PCR检测结果,将分离物597鉴定为地毯草黄单胞杆菌菜豆致病变种Xanthomonas axonopodis pv.phaseoli。     

菜豆普通细菌性疫病菌在土壤和植株残体中的越冬能力

为评估菜豆普通细菌性疫病菌地毯草黄单胞杆菌菜豆致病变种或褐色黄单胞菌褐色亚种在土壤及植物残体中的越冬能力,对采自黑龙江、内蒙古、山西、河北及新疆的18块菜豆生产田的20份土壤及14份植物残体样品进行病原菌分离和鉴定。在MT选择性培养基上有12个土壤样品和13个植株残体样品提取液产生典型的类似黄单胞菌菌落。选取29个分离物进行致病性测定,有27个分离物对菜豆品种"英国红"致病。利用地毯草黄单胞杆菌菜豆致病变种和褐色黄单胞菌褐色亚种的特异性引物X4c/X4e及褐色黄单胞菌褐色亚种特异性引物Xf1/Xf2对29个分离物进行多重PCR检测,其中17个分离物为地毯草黄单胞杆菌菜豆致病变种,10个分离物为褐色黄单胞菌褐色亚种。结果表明,菜豆普通细菌性疫病菌可以在黑龙江、内蒙古、山西、河北的一些菜豆种植区的土壤及植株残体中越冬存活。     

红掌细菌性疫病病原菌的PCR特异性检测

 红掌细菌性疫病(Xanthomonas axonopodis pv. dieffenbachiae,简称Xad)是红掌等天南星科花卉毁灭性病害,该病通过带菌种苗调运不断在我国扩散蔓延,国内尚未有检测方法。通过筛选和重新设计引物,建立了Xad 的PCR 检测方法,结果表明,利用引物Xad-F / Xad-R 进行PCR,能扩增出检测Xad 的特异性DNA 片断,其灵敏度可达1 × 102 CFU / mL,DNA 的最低检出限为0. 44 ng / μL,可用于红掌苗的带菌检测和红掌细菌病害的鉴定。     

7种检疫性植物病原黄单胞菌Ⅲ型分泌系统和效应蛋白编码基因的差异性分析

γ-变形菌纲(γ-Proteobacteria)的黄单胞菌属(Xanthomonas)的大多数种类可引起植物病害,多数是我国检疫对象。与其他革兰氏阴性植物病原细菌一样,植物病原黄单胞菌可通过高度保守的Ⅲ型分泌系统(type-Ⅲsecretion system,T3SS)分泌效应蛋白(T3SS-secreted effectors,T3SEs)进入植物细胞,在非寄主植物和抗病寄主植物上产生过敏反应(hypersensitive response,HR)以及在感病寄主植物上具有致病性。尚不清楚哪些种类的黄单胞菌具有T3SS和缺少哪些T3SE是否可作为检疫的依据。搜集7种检疫性植物病原黄单胞菌,通过PCR和Southern杂交试验结果发现:香蕉细菌性青枯病菌(X.campestris pv.musacearum)的ICMP287和ATCC49084菌株、甘蔗流胶病菌(X.axonopodis pv.vasculorum)ATCC13901菌株、洋葱细菌性叶枯病菌(X.axonopodis pv.allii)的LMG576和LMG578菌株中不含有tale基因,并且ATCC13901菌株既不含有T3SS基因也不含有hpal和xopQ基因;菜豆细菌性疫病菌(X.campestris pv.phaseoli)ATCC49119菌株不含有hpal基因。相应地,推测含有2~12个tale基因的黄单胞菌有:大豆斑疹病菌(X.axonopodis pv.glycines)ICMP5732和ATCC43911菌株、豌豆细菌性疫病菌(X.axonopodis pv.vignicola)ATCC11648菌株、棉花细菌性角斑病菌(X.campestris pv.malvacearum)ATCC12131和(X.campestris pv.phaseoli)ATCC49119菌株。大豆细菌性斑疹病菌ATCC43911菌株尽管含有hpal、xopQ和hrcC基因,但在非寄主烟草上不能激发HR反应;而甘蔗流胶病菌ATCC13901菌株不含有hpal、xopQ和hrcC基因,却激发烟草产生HR反应。这些结果对于分析比较不同植物病原黄单胞菌的致病性因子和设计特定的植物检疫靶点提供了科学线索。     

EPPO新增A1类检疫性有害生物——Xanthomonas axonopodis pv.allii

Xanthomonas axonopodis pv.allii 主要引起洋葱细菌性叶枯病,是EPPO新增加的A1类有害生物.本文对该菌的分布、寄主、症状、病原、发生规律、传播途径、检测鉴定、防治方法等方面进行了综述.     

豆薯细菌性角斑病的病原鉴定

 在安徽滁州的豆薯叶片上发现一种由细菌侵染引起角斑症状的病害,从角斑上分离到具有致病性的非荧光的杆状细菌,菌株的表型特征、细菌学特征、LOPAT试验和生理生化试验表明该细菌与丁香假单胞菌(Pseudomonas syringae van Hall)相似,BIOLOG系统鉴定结果与丁香假单胞菌豌豆致病变种(P.syringae pv.pisi)相近,接种试验表明豆薯菌株能侵染大豆、菜豆和眉豆,但对豌豆的致病性差;在豇豆、绿豆和蚕豆上不表现症状。结果表明豆薯细菌性角斑病是一种新病害,病原菌属于丁香假单胞菌群的一个新的致病变种,命名为P.syringae pv.pachyrhizus nov.     

进境柠檬样品上柑桔溃疡病菌的检测

从进境柠檬样品上分离到一株疑似柑桔溃疡病菌的分离物X206,对分离物进行了菌落形态学特征观察、16S r RNA序列测定、PCR检测、Biolog测定及致病性测试。试验结果表明分离物X206在NA培养基上形成黄色,有光泽,圆形,全缘,微隆起,粘稠状的菌落。特异引物Xac01/Xac02扩增分离物X206的DNA得到582bp的预期产物,产物序列与柑桔溃疡病菌序列的相似性为100%。其16S r RNA序列与柑桔溃疡病菌的序列完全一致。Biolog测定将分离物X206和柑桔溃疡病菌阳性菌株FZ01均鉴定为Xanthomonas campestris pv.dieffenbachiae。致病性测试显示分离物X206能导致柑桔叶片产生明显的溃疡病斑。根据试验结果将分离物X206鉴定为柑桔溃疡病菌(Xanthomonas axonopodis pv.citri)。     

进境澳大利亚绿豆中菜豆细菌性萎蔫病菌的检测

利用NA培养基从澳大利亚进境绿豆样品中分离到一株疑似菜豆细菌性萎蔫病菌(Curtobac-terium flaccumfaciens pv.flaccumfaciens,Cff)的细菌分离物2000-1,对该分离物进行革兰染色试验、PCR检测、多位点序列分析和致病性测试.分离物在NA平板上菌落浅黄色,圆形,隆起,黏性,...     

一种分离和鉴定辣椒细菌性斑点病的培养基

Xanthomonas campestris pv.vesicatoria 是引起辣椒和番茄细菌性斑点病的病原细菌,该菌为种传。初期研究中,利用叶片富集培养基从辣椒种子回收到这种病原菌;亦有利用半选择性的Tween 培养基从土壤(Tween B)、植物材料(Tween A)和番茄种子(Tween B)中分离到这种病原菌。Tween B 改良培养基,把头孢霉素Ⅵ、托普霉素和硼酸的量分别缩减46%、50%和67%,能明显地     

Rapd Pcr-based differentiation of Xanthomonas campestris pv. phaseoli and Xanthomonas campestris pv. phaseoli var. fuscans

A RAPD PCR-based method was used to differentiate between isolates of Xanthomonas campestris pv. phaseoli and Xanthomonas campestris pv. phaseoli var. fuscans. Using random primer OP-G11, a single, high intensity band of 820 bp was amplified from DNAs of all X. c. pv. phaseoli var. fuscans isolates, while multiple amplification products of varying sizes were generated from X. c. pv. phaseoli DNAs. Whereas RAPD PCR differentiation gave an unambiguous result in under 4 h, standard differentiation by recording the production of a brown pigment by X. c. pv. phaseoli var. fuscans isolates took up to 7 days and showed variation both between isolates and between media. The unequivocal nature of the RAPD PCR method was demonstrated when isolate 408, originally classified as X. c. pv. phaseoli var. fuscans, failed to produce the 820 bp band typical of X. c. pv. phaseoli var. fuscans isolates, and after also failing to produce a brown pigment, was re-classified as X. c. pv. phaseoli.     

The effect of populations of Xanthomonas campestris pv. phaseoli in bean reproductive tissues on seed infection of resistant and susceptible bean genotypes

Surface and internal populations of Xanthomonas campestris pv. phaseoli, causal agent of common bacterial blight of bean, on and in flower buds, blossoms and pods of seven bean (Phaseolus vulgaris) genotypes were studied. Bean plants were grown in the field and artificially inoculated at the seedling stage (18 days old). The pathogen was recovered in high numbers from flower buds, blossoms, pods and seed of both resistant and susceptible bean genotypes. Significant differences (P = 0.05) in population levels of X. c. pv. phaseoli between stages of reproductive tissue development were observed. Infected seed from resistant bean genotypes had no visible symptoms. Such seed may play an important role in the epidemiology of common bacterial blight because they are difficult to detect and may occur at low frequency in seed lots, as was the case in the current study.     

Interaction of common bacterial blight bacteria with disease resistance quantitative trait loci in common bean

Common bacterial blight (CBB) of common bean (Phaseolus vulgaris L.) is caused by Xanthomonas campestris pv. phaseoli and X. fuscans subsp. fuscans, and is the most important bacterial disease of this crop in many regions of the world. In 2005 and 2006, dark red kidney bean fields in a major bean-growing region in central Wisconsin were surveyed for CBB incidence and representative symptomatic leaves collected. Xanthomonad-like bacteria were isolated from these leaves and characterized based upon phenotypic (colony) characteristics, pathogenicity on common bean, polymerase chain reaction (PCR) with X. campestris pv. phaseoli- and X. fuscans subsp. fuscans-specific primers, and repetitive-element PCR (rep-PCR) and 16S-28S ribosomal RNA spacer region sequence analyses. Of 348 isolates that were characterized, 293 were identified as common blight bacteria (i.e., pathogenic on common bean and positive in PCR tests with the X. campestris pv. phaseoli- and X. fuscans subsp. fuscans-specific primers), whereas the other isolates were nonpathogenic xanthomonads. Most (98%) of the pathogenic xanthomonads were X. campestris pv. phaseoli, consistent with the association of this bacterium with CBB in large-seeded bean cultivars of the Andean gene pool. Two types of X. campestris pv. phaseoli were involved with CBB in this region: typical X. campestris pv. phaseoli (P) isolates with yellow mucoid colonies, no brown pigment production, and a typical X. campestris pv. phaseoli rep-PCR fingerprint (60% of strains); and a new phenotype and genotype (Px) with an X. campestris pv. phaseoli-type fingerprint and less mucoid colonies that produced brown pigment (40% of strains). In addition, a small number of X. fuscans subsp. fuscans strains, representing a new genotype (FH), were isolated from two fields in 2005. Representative P and Px X. campestris pv. phaseoli strains, an FH X. fuscans subsp. fuscans strain, plus five previously characterized X. campestris pv. phaseoli and X. fuscans subsp. fuscans genotypes were inoculated onto 28 common bean genotypes having various combinations of known CBB resistance quantitative trait loci (QTL) and associated sequence-characterized amplified region markers. Different levels of virulence were observed for X. campestris pv. phaseoli strains, whereas X. fuscans subsp. fuscans strains were similar in virulence. The typical X. campestris pv. phaseoli strain from Wisconsin was most virulent, whereas X. campestris pv. phaseoli genotypes from East Africa were the least virulent. Host genotypes having the SU91 marker-associated resistance and one or more other QTL (i.e., pyramided resistance), such as the VAX lines, were highly resistant to all genotypes of common blight bacteria tested. This information will help in the development of CBB resistance-breeding strategies for different common bean market classes in different geographical regions, as well as the identification of appropriate pathogen genotypes for screening for resistance.     

Genetic Diversity and Pathogenic Variation of Common Blight Bacteria (Xanthomonas campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans) Suggests Pathogen Coevolution with the Common Bean

ABSTRACT Common bacterial blight (CBB), caused by Xanthomonas campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans, is one of the most important diseases of common bean (Phaseolus vulgaris) in East Africa and other bean-growing regions. Xanthomonad-like bacteria associated with CBB in Malawi and Tanzania, East Africa, and in Wisconsin, U.S., were characterized based on brown pigment production, pathogenicity on common bean, detection with an X. campestris pv. phaseoli- or X. campestris pv. phaseoli var. fuscans-specific PCR primer pair, and repetitive element polymerase chain reaction (rep-PCR) and restriction fragment length polymorphism (RFLP) analyses. The common bean gene pool (Andean or Middle American) from which each strain was isolated also was determined. In Malawi, X. campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans were isolated predominantly from Andean or Middle American beans, respectively. In Tanzania, X. campestris pv. phaseoli var. fuscans was most commonly isolated, irrespective of gene pool; whereas, in Wisconsin, only X. campestris pv. phaseoli was isolated from Andean red kidney beans. Three rep-PCR fingerprints were obtained for X. campestris pv. phaseoli strains; two were unique to East African strains, whereas the other was associated with strains collected from all other (mostly New World) locations. RFLP analyses with repetitive DNA probes revealed the same genetic diversity among X. campestris pv. phaseoli strains as did rep-PCR. These probes hybridized with only one or two fragments in the East African strains, but with multiple fragments in the other X. campestris pv. phaseoli strains. East African X. campestris pv. phaseoli strains were highly pathogenic on Andean beans, but were significantly less pathogenic on Middle American beans. In contrast, X. campestris pv. phaseoli strains from New World locations were highly pathogenic on beans of both gene pools. Together, these results indicate the existence of genetically and geographically distinct X. campestris pv. phaseoli genotypes. The rep-PCR fingerprints of X. campestris pv. phaseoli var. fuscans strains from East African and New World locations were indistinguishable, and were readily distinguished from those of X. campestris pv. phaseoli strains. Genetic diversity among X. campestris pv. phaseoli var. fuscans strains was revealed by RFLP analyses. East African and New World X. campestris pv. phaseoli var. fuscans strains were highly pathogenic on Andean and Middle American beans. Breeding for CBB resistance in East African beans should utilize X. campestris pv. phaseoli var. fuscans and New World X. campestris pv. phaseoli strains in order to identify germ plasm with the highest levels of resistance.     

Phenotypic and Genetic Diversity in Strains of Common Blight Bacteria (Xanthomonas campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans) in a Secondary Center of Diversity of the Common Bean Host Suggests Multiple Introduction Events

ABSTRACT Common bacterial blight (CBB) disease of the common bean (Phaseolus vulgaris) is caused by Xanthomonas campestris pv. phaseoli and the brown-pigmented variant X. campestris pv. phaseoli var. fuscans. CBB first was described in Castilla y León County, Spain, in 1940, and is now a major constraint on common bean production. In this secondary center of diversity of the common bean, large-seeded Andean cultivars predominate, although medium-seeded Middle American cultivars also are grown. Xanthomonad-like bacteria associated with CBB in Castilla y León were characterized on the basis of carbohydrate metabolism, brown pigment production, genetic analyses (repetitive-element polymerase chain reaction [rep-PCR] and random amplified polymorphic DNA [RAPD]) and pathogenicity on cultivars representing the two common bean gene pools (Andean and Middle American). X. campestris pv. phaseoli was more prevalent (80%) than X. campestris pv. phaseoli var. fuscans (20%). Patterns of carbohydrate metabolism of Spanish CBB bacteria were similar to those of known strains; and only X. campestris pv. phaseoli var. fuscans strains utilized mannitol as a sole carbon source. rep-PCR and RAPD analyses revealed relatively little genetic diversity among Spanish X. campestris pv. phaseoli strains, and these strains were placed together with New World strains into a large cluster. Similar to other New World strains, representative Spanish X. campestris pv. phaseoli strains were highly pathogenic on bean cultivars of both gene pools, showing no gene pool specialization such as that found in certain East African strains. Genetic analyses and pathogenicity tests confirmed and extended previous results, indicating that these East African strains represent distinct xanthomonads that independently evolved to be pathogenic on common bean. X. campestris pv. phaseoli var. fuscans strains were more closely related and genetically distinct from X. campestris pv. phaseoli strains. However, two distinct clusters of X. campestris pv. phaseoli var. fuscans strains were identified, one having the most New World strains and the other having the most African strains. Spanish strains were placed in both clusters, but all strains tested were highly pathogenic on bean cultivars of both gene pools. Together, our results are consistent with multiple introductions of CBB bacteria into Spain. These findings are discussed in terms of breeding for CBB resistance and the overall understanding of the genetic diversity and evolution of CBB bacteria.     

Characterization of pathotypes among isolates of Xanthomonas axonopodis pv. manihotis in Colombia

Cassava bacterial blight, caused by Xanthomonas axonopodis pv. manihotis ( Xam ) is a destructive disease occurring in most cassava growing-areas. Although Colombian isolates of Xam differ in DNA polymorphism and pathogenicity, no suitable host differentials have been identified to demonstrate physiological specialization. A set of 26 Xam isolates from three edaphoclimatic zones (ECZs) in Colombia was selected for inoculation on a set of 17 potential cassava differentials. Leaf inoculation and stem puncture were used in order to detect possible specific interactions between cultivars and isolates. Cultivar × isolate interaction was highly significant ( P  < 0·001) after stem inoculation, but not after leaf inoculation. The stem inoculation technique was selected as a method for resistance screening of cassava cultivars for bacterial blight resistance. A highly significant interaction was also detected when cultivar behaviour was rated as area under the disease progress curve (AUDPC) after stem inoculation. Different pathotypes were defined among the 26 isolates and differential cultivars were proposed to define the pathotypic composition of Xam populations in three ECZs in Colombia. The results should help to improve selection of sources of resistance to cassava bacterial blight.     

Induction of superoxide dismutase,malate dehydrogenase and phenylalanine ammonia-lyase during enhancing resistance of common bean against Xanthomonas axonopodis pv. phaseoli by exogenous salicylic acid

Journal of Plant Diseases and Protection - Bacterial blight of common bean caused by Xanthomonas axonopodis pv. phaseoli (Xap) is one of the most devastating diseases and causes serious yield...     

水稻白叶枯病菌和细菌性条斑病菌的分子标记筛选及检测

 水稻白叶枯病菌（Xanthomonas oryzae pv. oryzae）和细菌性条斑病菌(Xanthomonas oryzae pv. oryzicola)是水稻种子产地检疫中最重要的两种检疫对象,且同属于水稻黄单胞杆菌。本研究基于生物信息学技术构建比较基因组学算法对两种病原的全基因组序列比对分析,得到一系列能够区分两种病原的特异性PCR引物。结合简单的PCR技术及全自动DNA分析系统,我们选取了12对引物分别对23株水稻白叶枯病菌和5株水稻细菌性条斑病菌及其它相关菌株进行验证。结果获得了2对显性标记(Xoo-Hpa1和Xoc-ORF2)以及3对共显性分子标记(M568、M897和M1575)可以达到理想的区分检测两种病原的效果。分子标记的检测灵敏度从5×10⁴到5 × 10⁷cfu·mL^-1不等,且从水稻种子浸提液中也能成功地检测水稻白叶枯病菌和细菌性条斑病菌。本研究丰富了检测标记的靶位点,并有效的结合了高通量检测的手段对多位点联合分析,增强了检测的可靠性,有望在今后的植物检疫及病原鉴定中发挥着重要的作用。     

Identification of Resistance to Common Bacterial Blight Disease on Bean Genotypes Grown in Turkey

Common bacterial blight (CBB) in edible beans (Phaseolus vulgaris), incited Xanthomonas campestris pv. phaseoli, reduces bean yields and seed quality. The main objective of this study was to determine resistance to common bacterial blight in bean genotypes. Twenty-two bean genotypes grown in Turkey including common and snap bean cultivars/lines were collected from different parts of Turkey and tested for resistance against to Xanthomonas campestris pv. phaseoli strain MFD-11. All the common and snap bean lines/cultivars tested were moderately susceptible, susceptible or highly susceptible, except AG-7117 which was found resistant to Xanthomonas campestris pv. phaseoli. This is the first report of a resistance source in a common bean line (AG-7117) against Xanthomonas campestris pv. phaseoli.