花椒枯穗病病原鉴定

Ten Zanthoxylum bungeanum ear blight diseased samples were collected from the Research Base of Forestry Research Institute of Hebei Province of China during 2009. Three isolates were obtained from diseased samples and no distinct difference could be observed among them. The fungus E-1 was determined to be responsible for this disease by the Koch’s Postulation. Morphological and the phylogenetic tree constructed based on ITS sequences showed that the morphological characters were the same as Alternaria alternata and the homology between E-1 and A. alternata was up to 100 percent. It indicated that E-1 was A. alternate（JQ973810）.     

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。     

如何防治西瓜蔓枯病

西瓜蔓枯病又叫黑腐病。近几年随着农业产业结构调整，种植西瓜面积逐年扩大，西瓜蔓枯病已成为本市瓜类作物的１个主要病害，当地人俗称“流黄水病”。常年西瓜蔓枯病发病率２７．３％～４７．８％，重发田块病株率高达６７．５％，严重威胁着西瓜的高产、稳产。１症状西瓜整个生育期地上部分均可发病，引起叶、蔓枯死和果实腐烂。子叶发病，初呈水渍状小点，渐扩大为黄褐色或青灰色圆形或不规则形斑，不久扩展至整个子叶，引起子叶枯死。幼苗茎部受害，初现水渍状小斑，后迅速向上、下扩展，并可环绕幼茎，致使幼苗枯萎死亡。成株发病多见…     

西瓜蔓枯病及防治

西瓜蔓枯病及防治丰硕（湖北省洪湖市沙口农技站，４３３２０５）西瓜蔓枯病又叫黑腐病、斑点病、朽根病，危害叶片、茎蔓、果实等，以叶片受害最重。发病症状：片感病最初出现黑褐色小斑点，后逐渐变为直径为１～２厘米的病斑，病斑后期散生小黑点，病叶干枯时呈星状破裂...     

安徽省茶树细菌性梢枯病病原鉴定

2017年-2018年在安徽省庐江、东至县茶园种植区发现一种茶树新病害——梢枯病,发病症状表现为顶芽枯死,嫩叶叶柄变褐,叶片枯萎.为明确庐江、东至县茶树梢枯病的病原菌,采用平板划线法和稀释涂布平板法分离病原,按照柯赫氏法则对病原细菌进行致病性测定,并利用细菌的表型特征和分子生物学技术确定病原菌的分类地位.结果表明,从茶...     

鸡骨草叶枯病调查及其病原鉴定

在广西鸡骨草种植基地,发现一种发生严重的叶枯病,植株自下部叶片开始枯黄,然后向上蔓延,严重时整株枯死。经田间调查、标本采集、病原菌分离、形态学鉴定及致病性测定,明确该病害由丝核菌属（Rhizoctonia）引起。该病害在田间的发病率为69%～88%,病情指数为17.4～34.6。     

籽西瓜蔓枯病的发生与防治

籽西瓜蔓枯病的发生与防治许浩然许莉（新疆自治区沙湾县农技中心８３２１００）尹玉芬（沙湾县金沟河乡政府）籽西瓜蔓枯病除为害籽西瓜外,常见为害甜瓜、西瓜。１９９７年沙湾县大流行,籽西瓜受害面积１４０ｈｍ２,严重受害面积４７ｈｍ２,瓜籽减产９．６ｔ,实际经...     

西瓜蔓枯病的发生与防治措施

对西瓜蔓枯病进行调查、监测,掌握其发病规律,及时防治,使西瓜产量和质量得到保障,提高瓜农的经济收入。     

荆芥茎枯病病原菌的分离与鉴定

 The pathogen causing stem blight was isolated from diseased stem of Schizonepeta tenuifolia Briq.. Based on rDNA-ITS analysis, morphological characteristic and pathogenicity test, the pathogen was identified as Phytophthora nicotianae.     

狗牙花叶枯病病原菌分离鉴定

狗牙花叶枯病是江西农业大学花圃重要病害之一。本文按照柯赫氏法则对狗牙花叶枯病病原进行了分离鉴定，鉴定结果为胶孢炭疽菌（Colletotrichum gloeosporioides(Penz.)Sacc.).     

Dynamics of the ascospore dispersal of Stagonosporopsis citrulli,a causal agent of gummy stem blight of cucurbits

Sexually reproduced, airborne ascospores of Stagonosporopsis citrulli may play a role in its dispersal. S. citrulli causes gummy stem blight (GSB), one of the most important foliar diseases of cucurbits. Four studies were conducted with S. citrulli to investigate for how long ascospores are released and how far they can be dispersed from a source field. In the first study, colonized watermelon debris was sampled during three seasons and samples were assayed for ascospore release. Ascospores were detected 292, 313, and 306 days after inoculation of the source. In the second study, the active release of ascospores from pseudothecia in a Petri dish was monitored for 7 days. The release of ascospores decreased by ≤90% from 1 day after the start of the assay until 7 days after. In the third study, trap plant assays were conducted to measure the dispersal gradient of ascospores up to 366 m from the source. Generally, frequency of pathogen recovery from trap plants decreased with increasing distance from the source. The ascospore dispersal data fitted the exponential model better than the power law model. In the final study, dispersal experiments were conducted under controlled conditions. The incidence of GSB decreased with increasing distance, up to 55 m, from the source. It was concluded that ascospores of S. citrulli can serve as primary inoculum for epidemics and could easily spread among fields. Debris from cucurbit crops can be the source of ascospores for up to 10 months and should be cleared expeditiously.     

广西苦瓜棒孢叶斑病的病原鉴定

<正>0 引言苦瓜(Momordica charantia L.)又称为凉瓜,是葫芦科苦瓜属一年生攀缘植物,兼具食用与药用价值,也是广西“南菜北运”的重要瓜类蔬菜^[1]。苦瓜棒孢叶斑病是苦瓜大棚生产中的一种常见病害,主要发生于苦瓜生长的中后期,以叶片为害为主。据调查,广西大棚中苦瓜棒孢叶斑病发病率约为40%,严重影响苦瓜的生长发育。该病害在韩国和我国的山东均有报道^[2-3]。棒孢病菌产生的cassiicolin毒素蛋白是主要的致病因子,     

西瓜品种资源对枯萎病和蔓枯病的抗性鉴定

采用室内苗期人工接种鉴定方法,对国内外引进和育成的78份西瓜品种资源进行了枯萎病和蔓枯病的人工接种双重抗性鉴定,筛选出Smokylee、 Summit、 Sugarlee、Calhoun Gray、 Dixielee、TexaW5、 Conqueror等9份高抗枯萎病的单抗种质,及AU Sweet Scarlet、 AU Jubilant、 AU Producer、W6 9、W23 18和W23 47 为中抗蔓枯病兼抗枯萎病的双抗种质,并对双抗种质材料的主要农艺性状进行了考察。     

不同甜瓜品种蔓枯病抗性与抗坏血酸过氧化物酶 基因 表达的关系

 蔓枯病是威胁甜瓜最重要的病害之一,该病是由西瓜壳二孢菌(Ascochyta citrullina Smith, 无性世代是泄根亚隔孢壳Didymella bryoniae)引起的,在甜瓜的幼苗期至采收期均可发生。在中国厚皮甜瓜栽培品种中尚未发现蔓枯病抗性较好且综合性状优良的品种,多数甜瓜抗蔓枯病材料均为薄皮小果,关于甜瓜与蔓枯病菌的互作机理目前报道较少,厚皮甜瓜和薄皮甜瓜与蔓枯病菌的互作机理差异以及不同品种的薄皮甜瓜间与蔓枯病菌的互作机理差异未见任何报道。在低温高湿环境下甜瓜发生蔓枯病的几率比在适宜生长环境下大大增高,抗坏血酸过氧化物酶(ascrobate peroxidase gene,APX,EC1. 11. 1.11) 是植物耐受逆境胁迫的主要因子,调节活性氧水平,与过氧化氢、一氧化氮一起参与防卫反应和细胞死亡,有可能调节MAPK的级联反应,应对多种环境胁迫因子。本研究拟探讨不同甜瓜品种与蔓枯病菌互作时APX转录水平的变化,初步解释APX在甜瓜与蔓枯病菌互作中的作用。     

瓜拟多隔孢引起的砂田西瓜叶疫病

 近年来,甘肃省白银市靖远县的一些砂田西瓜中出现了严重的叶疫病,严重田块病株率超过70%。2018年7月,从靖远县高湾乡罹病西瓜叶片上分离得到拟多隔孢属Stagonosporopsis真菌,病叶检出率达100%。采用离体叶片和植株接种法评价单孢分离菌株XG-3对西瓜和甜瓜的致病性,所有接种处理在24 h内均发病显症而对照未发病,其中发病叶片原接种菌的检出率为100%。菌株XG-3在PDA和OA平板培养基上20和25 ℃培养20 d,未见产孢。在自然感病的西瓜叶片上观察到少量分生孢子器,在人工接种发病的西瓜和甜瓜茎、叶上产生大量分生孢子器和分生孢子:分生孢子器球形至亚球形,大小为(82.4~243.3) μm×(82.4~188.4)μm,分生孢子器具1~2个孔口,孔口直径15.7~27.5 μm;分生孢子无色,0~3个隔膜,杆状、柱状、长椭圆形、花生形及不规则形,直或稍弯曲,分隔处不缢缩或缢缩,大小为(5.2~28.3)μm×(2.2~6.0)μm,分生孢子形态和大小依基质和环境条件的不同而有较大差异。BLASTn分析结果显示,菌株XG-3(GenBank登录号:MW282128)的rDNA-ITS序列与瓜拟多隔孢Sta. cucurbitacearum分离物287ITS(GenBank登录号:AY293804.1)的序列相似性达99.80%。在基于rDNA-ITS构建的系统发育树中,菌株XG-3与Sta. cucurbitacearum聚为一组,与西瓜拟多隔孢Sta. citrulli和木瓜拟多隔孢Sta. caricae区分开来。依据病菌形态学和分子生物学特征,将菌株XG-3鉴定为瓜拟多隔孢Sta. cucurbitacearum [Basionym: Sphaeria cucurbitacearum]。     

辽宁梨树枝枯病病原菌Diplodia seriata的分离与鉴定

在辽宁兴城秋子梨栽培园出现一种新型枝干病害,主要症状为枝枯及木质部坏死。为明确梨树枝枯病病原菌的分类地位,本研究从辽宁兴城地区采样,经过菌株分离培养和致病性测定,以及形态学鉴定结合病原菌的ITS、EF-1α和β-tubulin多基因联合构建系统发育树,确定引起秋子梨枝枯病的病原菌为色二孢Diplodia seriata。研究结果为明确色二孢引起的辽宁梨树枝枯病发生规律和防治措施的制定提供了理论基础。     

黑老虎枝枯病病原鉴定及其生物学特性

<正>黑老虎[Kadsura coccinea (Lem.) A. C. Smith]又名冷饭团、布福娜,果实含丰富的Vc、Ve及多种微量元素,是山区野果珍品[1]。上世纪末,人们从野外引种试栽,目前在黔东南地区实现了规模化栽培。笔者于2017和2018年调查发现,黑老虎枝枯病在黔东南州各种植基地普遍发生,造成严重损失,但关于黑老虎病害的报道甚少[2,3]。本研究对黑老虎枝枯病的病原菌进行了分离培养、柯赫氏法则验证、形态学特征观察及多基因序列     

黑老虎枝枯病病原鉴定及其生物学特性

Kadsura coccinea (Lem.) A. C. Smith has been wildly cultivated in Southeast of Guizhou province, bearing fruit as an excellent nutrition source being rich in vitamin C, vitamin E, and a variety of trace elements. In 2017-2018, we found twig blight on Kadsura coccinea with small black dot-like structure in the late stage on lesion, a very common disease causing significant economic losses. The fungal isolates were recovered from the symptomatic stem tissues and small black dot (pycnidium) which contained transparent, unicellular and spindle-shaped conidia of (17.4±1.2) μm×(6.5±0.7) μm. The purified culture with the grayish white to dark grayish-green as well as partial straight hyphae on PDA plate was consistent with Neofusicoccum parvum, supported by the aliment and phylogenetic analyses of ITS, Ef1 α and Tub2 gene sequences (GenBank no: MK563984、MK563986 and MK563987).The pathogenicity test on leaves and stems with needle-punching method matched the symptoms described above and re-isolated the fungus confirming the Koch’s postulate. The lethal temperature for mycelial growth was 54℃ for 10 min; The strain could grow normally in most carbon and nitrogen sources except ammonium carbonate. This is the first report of Neofusicoccum parvum causing twig blight on Kadsura coccinea in China.     

广西黑皮冬瓜疫病的病原菌鉴定及其生物学特性

 Isolate PD1 of Phytophthora was isolated from diseased black pericarp wax gourd in Guangxi in 2005. The morphological and biological characters of the isolate were examined, and its sequence of ribosomal DNA-ITS was analyzed. The range of growth temperature of the isolate was 10-37℃ and the optimal one was 31℃. The pathogen was sensitive to 10 mg/kg of malachite green, and its ability for starch utilization was weak. A wide host range of the pathogen was confirmed by artificial inoculation. The sizes of sporangia were (37.5-71.7) μm×(20.8-47.5) μm (av. 55.0 μm×30.4 μm). Microcycle conidiation of the pathogen was observed. The pathogen was identified as Phytophthora drechsleri Tucker based on its morphological and biological characters as well as ribosomal DNA-ITS sequence.