江西省国外松枯梢病调查及病原鉴定

连续3年在江西省境内,对松枯梢病的分市、危害及病原菌进行了广泛的调查及病原鉴定。结果证明松枯梢病遍布我省6个地区、10个市及30余个县的火炬松林、湿地松林,从苗木到幼树仍至大树均可发病．发展迅速,危害较严重．已有成片死亡、马尾松发病很轻。该病害病原苗是Diplodiapinea（Desm）Kickx。     

厚皮香枯梢病病原菌鉴定

厚皮香枯梢病在上海地区发生严重。本研究对上海地区的厚皮香枯梢病进行了病原菌的分离与致病性鉴定,得到其病原菌菌株2017SHTg。根据病原菌的形态特征将其鉴定为小新壳梭孢Neofusicoccum parvum。扩增病原菌2017SHTg的rDNA-ITS序列和翻译延伸因子EF-1α基因序列,进行BLAST序列比对与小新壳梭孢相似性分别为99%和100%;基于rDNA-ITS序列构建系统发育进化树,其在系统发育树上与小新壳梭孢的类群处于同一分支,此结果与形态学鉴定结果一致。     

岗梅枝枯病病原鉴定

为明确引起岗梅Ilex asprella枝枯病的病原,对从广东梅州采集的岗梅枝枯病病部分离的致病菌株Gangmei 2进行了形态学观察,并运用MEGA-X构建了病原菌株rDNA内转录间隔区(internal transcribed spacer, ITS)的系统发育树。结果显示:病原菌的形态学特征与拟盘多毛孢属Pestalotiopsis真菌相似,在系统发育树中该菌株与小孢拟盘多毛孢菌Pestalotiopsis microspora在同一分支上。因此,初步将岗梅枝枯病病原菌鉴定为小孢拟盘多毛孢菌P.microspora。     

冬枣嫩梢焦枯病病原初步鉴定

2003-2004年从山东省滨州市沾化县、无棣县等冬枣种植园进行病害调查,采集冬枣病叶、病枣吊等病样35份,经室内分离、纯化获得8个菌株。从中选出3个菌株,对其细菌形态、染色反应、致病性测定和生理生化反应等性状进行了,较系统研究。鉴定结果表明,3个菌株均属于洋葱假单胞杆菌(Pseudomonas cepacia Burkholder)。     

注意控制湿地松枯梢病的传播蔓延

湿地松是我国引自北美的一个优良速生树种,从七十年代以来,江西各地陆续开始引种造林,面积也越来越大,一个又一个的湿地松用材林、采脂林、造纸林基地被建设起来,为加速荒山绿化,发展林业作出了贡献。但是,也必须客观地看到,随着湿地松造林面积的不断扩大,威     

从进境落叶松树苗上检出落叶松枯梢病

20 0 2年 7月从日本进境的兴安落叶松树苗在隔离种植检疫中发现树苗的新梢上有枯死现象 ,经鉴定为落叶松枯梢病 (Guig nardialaricina (Sawada)Yamamotoetk .Ito)。这是黑龙江局首次截获落叶松枯梢病菌 ,现将落叶松枯梢病菌的检验检疫和有关情况简介如下。1　分布与危害落叶松枯梢病是中国森林植物检疫对象。该病最早发现于日本 ,1 96 2～ 1 96 9年间曾给日本造成极大的损失。目前该病在国外主要分布在日本、朝鲜。国内主要分布在黑龙江、吉林、辽宁 ,其次在河北、山东、等有少量的分布 ,它的主要寄主是落叶松 (Lar ixgxelini)、华北落叶…     

哈密瓜细菌性果斑病病原菌鉴定

 2000年在内蒙古和新疆的哈密瓜上发现一种新细菌病害-哈密瓜细菌性果斑病,从病叶和病果上分离到33个细菌菌株,接种哈密瓜、西瓜和甜瓜后,发病症状与自然发病症状完全一致,而且从接种病株上又重新分离到了此病原细菌,这33个细菌菌株经柯赫法则证明均为该病的致病菌。各菌株致病力无明显差异。经革兰氏染色反应、菌体形态、培养性状、生理生化反应、细胞化学成分分析(糖、蛋白质、氨基酸、脂肪酸、mol% G+C)、DNA-DNA杂交,确认该病原菌为燕麦食酸菌西瓜亚种(Acidovorax avenae subsp.citrulli Willems et al.1992)=类产碱假单胞菌西瓜亚种(Pseudomonas pseudoalcaligenes subsp.citrulli Schaad et al.1978)。该病菌除侵染哈密瓜外,人工接种尚能侵染多种葫芦科及番茄、茄子等作物。     

黄皮梢腐病病原菌鉴定

 黄皮[Clausena lansium(Lour.)Skeels]是一种风味独特的亚热带水果,为我国特产。     

水稻危险性病害——细菌性谷枯病及其病原鉴别

为正确识别水稻细菌性谷斑病及其病原 ,以预防其在我国的传播与蔓延 ,本文对该病的分布、症状、病原、初侵染源及病原的鉴别作了描述     

哈密瓜细菌性果斑病菌群体感应系统的检测

本文利用群体感应信号报告菌Agrobacterium tumefaciens NTL4(pZLR4),在LB报告平板上对燕麦食酸菌西瓜亚种的19个菌株进行了初步检测,发现18个菌株有群体感应信号产生.用琼脂条法对菌株Pslb-94进一步检测,证实菌株Pslb-94存在群体感应系统.提取了该菌株信号物质,反相薄层层析(TLC)检测证明该菌株能产生群体感应信号分子.     

利用GICA-PCR快速检测瓜类果斑病菌

瓜类果斑病菌(Acidovorax avenae subsp.citrulli,Aac)是瓜类作物上重要的病原细菌,为我国进境植物检疫性有害生物。胶体金免疫层析试纸条方便快捷,应用广泛。该方法使用不当会出现假阳性问题,仅适用于病原菌的初筛检测。本研究将Aac胶体金免疫层析方法(GICA)与PCR技术相结合,建立了GICA-PCR检测方法。检测结果表明,该方法在蛋白与核酸2个层面上从发病西瓜叶片上检测到瓜类果斑病菌,有效解决了试纸条检测的假阳性问题,提高了瓜类果斑病菌检测的准确性,值得推广应用。     

应用蛋白宏阵列快速检测西瓜细菌性果斑病菌

蛋白阵列(Protein array)也叫蛋白芯片,是生物芯片(Biochip)的一种,主要利用抗原/抗体可特异性结合原理制备而成。按阵列样点大小,蛋白阵列又可分为微阵列(Microarray)和宏阵列(Mac-roarray)两类。微阵列集成度极高,可进行高通量     

兰花褐斑病菌实时荧光PCR检测

兰花褐斑病菌(Acidovorax avenaesubsp.cattleyae)是兰花上一种重要进境检疫性有害生物,可通过植株和种子远距离传播,其传染性强,对兰花危害性大。根据核糖体ITS序列设计了TaqMan-MGB探针并建立了实时荧光PCR检测方法。该方法能够特异性检测兰花褐斑病菌,所有供试的目标菌株检测结果均为阳性,而其它28个对照菌株(含同属内其它种及avenae种下其它亚种)均为阴性。利用该方法从发病兰花植株总DNA中检测到该病菌。本方法灵敏度高,检测极限达9×10-9μg DNA,操作方便快速,结果可靠,适合于口岸兰花的进出境检疫及兰花种苗健康质量控制。     

Genetic diversity and population structure of Acidovorax avenae subsp. avenae isolated from sugarcane in Argentina

A significant increase in the occurrence of red stripe (caused by Acidovorax avenae subsp. avenae) has been observed in the last decade in Argentina. Considering that no extensive sampling of the main sugarcane-producing area in the country has been conducted to characterize the diversity and population structure of A. avenae subsp. avenae, molecular markers were employed to analyse 112 isolates from Tucumán. By using repetitive element polymorphism-based polymerase chain reaction (rep-PCR) almost all isolates were differentiated and grouped into 10 clusters, revealing a high genetic diversity. Using the amplified fragment length polymorphism (AFLP) technique, five pairs of isolates were discriminated that could not be distinguished with rep-PCR. Cluster analysis showed no clear association between isolate clustering, sugarcane host genotype, crop age, type of tissue sampled, fertilization, or year of sampling. Linkage equilibrium analysis by using rep-PCR data indicated that the population has some degree of clonality. Three housekeeping genes were also sequenced: ugpB and pilT sequences were highly similar to A. avenae subsp. avenae sequences from other Argentinian isolates, whereas the lepA sequence did not reveal significant similarity. An additional four housekeeping genes could not be amplified, suggesting the existence of differences in those regions. Subsequently, virulence of 14 A. avenae subsp. avenae isolates was evaluated under controlled conditions. Results showed a differential level of aggressiveness among the isolates on a resistant sugarcane variety. This study confirmed that rep-PCR is an adequate tool for genetic analysis and population structure characterization in bacteria, and revealed both high genetic diversity and clonal population structure of A. avenae subsp. avenae in Tucumán, Argentina.     

免疫凝聚试纸条和TaqMan探针实时荧光PCR检测西瓜细菌性果斑病菌比较研究

 以西瓜细菌性果斑病菌(Acidovorax avenae subsp.citrulli)菌悬液和田间采集的病组织为试材,研究了免疫凝聚试纸条和实时荧光PCR技术检测的灵敏度和适应性。结果表明,免疫凝聚试纸条检测灵敏度为10⁶ cfu/mL,具有简便、快速、易操作特点,适用于田间快速检测和病害诊断;TaqMan探针实时荧光PCR检测灵敏度达10^3~4 cfu/mL,比传统PCR检测灵敏度(10⁵ cfu/mL)提高了10~100倍,且不需要琼脂糖凝胶电泳、溴化乙锭染色和Southern杂交。但需要昂贵的仪器和试剂,适用于室内检测及相关研究。     

辣木枝枯病病原菌鉴定及其生物学特性

为明确海南省辣木枝枯病病原菌及其生物学特性,采用组织分离法获得菌株MO157,通过柯赫氏法则、形态学特征及分子生物学技术对该菌株进行鉴定,并测定了其菌丝生长的最佳条件。结果表明,菌株MO157回接10 d后,辣木茎干表面周围呈黄褐色,随后发病部位表现出水渍状病斑,与自然发病辣木的病状相符;菌落近圆形,菌丝初期呈白色绒毛状,后期呈浅黄色,分生孢子顶胞钩状,3~5个隔膜,厚垣孢子呈球形,在菌丝间串生;菌株MO157的ITS序列与Gen Bank中木贼镰刀菌Fusarium equiseti的相似性为100%,结合形态特征与分子鉴定最终将其确定为木贼镰刀菌(Gen Bank登陆号:KX197955)。该菌菌丝生长适宜温度25~30℃,最适温度28℃;pH 6~8时菌丝生长速率增快,pH 7时最适菌丝生长;PDA培养基和PSA培养基最适合该菌生长,以蔗糖为碳源时利用率最高;以牛肉浸膏为氮源时利用率最高;该菌致死温度为65℃,10 min;光照对菌丝生长影响较小,不同处理间菌落直径无显著差异。     

甜瓜细菌性果斑病菌致病性突变体筛选与hrcR基因的克隆

 细菌性果斑病(Bacterial Fruit Blotch,BFB)是西瓜和甜瓜的重要病害。本实验从发病甜瓜果实上分离得到致病菌株MH21,经鉴定为燕麦食酸菌西瓜亚种(Acidovorax avenae subsp. citrulli)。利用转座子Mini-Tn5构建MH21菌株的突变体库,Southern印迹杂交结果显示Mini-Tn5在菌株MH21染色体上可随机、单拷贝插入。通过浸种处理甜瓜种子进行突变体的致病性检查,筛选得到1株致病性完全丧失的突变体M543。对M543中转座子插入基因的克隆和测序表明其突变基因为燕麦食酸菌Ⅲ型分泌系统(TTSS)中的保守基因hrcR。推测菌株MH21中hrcR基因编码的蛋白定位于细菌内膜,是分泌通道主要成分之一。hrcR基因互补菌株的致病性检查结果显示其致病力恢复到野生型的84%。研究同时发现hrcR基因突变后MH21菌株丧失了在烟草上诱导过敏性坏死反应的能力。本研究从遗传学角度说明TTSS是西甜瓜果斑病菌致病性的重要因子。     

Molecular identification and prevalence of Acidovorax avenae subsp. avenae causing red stripe of sugarcane in China

Red stripe caused by the bacterium Acidovorax avenae subsp. avenae (Aaa) is a disease of sugarcane that is distributed worldwide. In this study, 108 sugarcane leaf samples were collected in 2013–2016 from nine sugarcane‐growing regions in China. Aaa was detected by PCR with specific and novel primers from the 16S–23S rDNA internal transcribed spacer region in 81 of 84 (96%) leaves with red stripe symptoms and in 20 of 24 (83%) leaves without symptoms. Furthermore, Aaa was detected in all nine sampling locations representing six sugarcane‐producing provinces in China. The 101 amplified fragments were cloned and sequenced. The size of the nucleotide sequences varied from 436 to 454 bp and the sequence identity ranged from 89.2% to 100%, suggesting a significant genetic variation among Aaa strains from China. Five major restriction fragment length polymorphism (RFLP) profiles were obtained by in silico and polyacrylamide gel electrophoresis analyses of the PCR products digested with HindIII and EcoRI. The causal agent of sugarcane red stripe was also successfully isolated from a diseased plant and its pathogenicity confirmed by inoculation of healthy sugarcane plantlets and reproduction of disease symptoms. The data showed that Aaa is currently widespread in China, suggesting that control methods should be implemented to limit the impact of red stripe on sugarcane production.