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.     

番茄叶片漆腐病病原菌鉴定

 A new leave disease of tomato (Lycopersicon esculentum Miller) was observed in polyethylene film-covered greenhouse in Beijing, China. This disease spreaded rapidly in the greenhouse and caused serious loss of the production of tomatoes. In the study, a fungal strain isolated from the lesion was confirmed to be pathogen for this new disease, and identified as Myrothecium roridum Tode ex Ft. based on the morphology, cultural characters on PDA plate and sequence analysis of ribosomal DNA-ITS. This is the first report of myrothecium leaf spot on tomato occurring in commercial greenhouse in China.     

Intra-annual stem diameter growth of Tamarix ramosissima and association with hydroclimatic factors in the lower reaches of China’s Heihe River

High-resolution observations of cambial phenology and intra-annual growth dynamics are useful approaches for understanding the response of tree growth to climate and environmental change. During the past two decades, rapid socioeconomic development has increased the demand for water resources in the oases of the middle reaches of the Heihe River in northwestern China, and the lower reaches of the Heihe River have changed from a perennial river to an ephemeral stream with a decreased and degraded riparian zone. Tamarisk（Tamarix ramosissima） is the dominant shrub species of the desert riparian forest. In this study, the daily and seasonal patterns of tamarisk stem diameter growth, including the main period of tree ring formation, were examined. Observations concerning the driving forces of growth changes, along with implications for the ecology of the dendrohydrological area and management of desert riparian forests in similar arid regions, are also presented. The diurnal-seasonal activity of stem diameter and the dynamics of growth ring formation were studied using a point dendrometer and micro-coring methods during the 2012 growing season in shrub tamarisk in a desert riparian forest stand in the lower reaches of the Heihe River in Ejin Banner, Inner Mongolia of northwestern China. Generally, the variation in diurnal diameter of tamarisk was characterized by an unstable multi-peak pattern, with the cumulative stem diameter growth over the growing season following an S-shaped curve. The period from late May to early August was the main period of stem diameter growth and growth-ring formation. Among all of the hydroclimatic factors considered in this study, only groundwater depth was significantly correlated with stem diameter increment during this period. Therefore, for the dendrochronological study, the annual rings of the tamarisk can be used to reconstruct processes that determine the regional water regime, such as river runoff and fluctuations in groundwater depth. For the management of desert riparian for     

灰枣红点软腐病病原菌的鉴定

 The damage and symptoms of jujube fruit soft rot in Xinzheng, Henan Province, were investigated from 2006 to 2008, and the pathogen was identified based on the morphological characteristics and the ITS se-quence of ribosome DNA. The results showed that the aerial mycelium of colony was white in color in the first four days, then turned gray after incubation on PDA for 5-6 d at 25℃ and became black two weeks later. The mycelia grew luxuriantly with velvet character. The pycnidium was flask-shaped with a height of 196.9μm and a width of 213.3μm on the avereage. The conidium was colorless with single cell and had the shape of spindle, its size was (15.0-20.0)μm× (4.5-6.5)μm. The conidiophore was fastigiate. The homology of ITS sequence of ribosome DNA between the tested strain NXK and Botryosphaeria dothidea (GenBank ac-cession number:AJ938005) reached 99.87%, with a difference of only two base pairs. Based on the results of both morphological characters and molecular identification, the pathogen of jujube fruit soft rot in Xinzheng was identified as B. dothidea (Moug. ex Fr.) Ces. et de Not..     

阔叶十大功劳炭疽病初报

 A new leaf spot disease of Mahonia healei was found in Guangxi China, which was one of the limitations for the growth of M. healei. Based on the morphology, pathogenicity and the analysis of sequences of ribosome rDNA-ITS, the pathogen of M. healei anthracnose disease was identified as Colletotrichum gloeosporioides (Penz.)Sacc.     

苍术黑斑病病原鉴定

 The pathogen causing dark leaf spot on Atractylodes lancea was isolated from diseased leaf. Based on morphological characteristics, pathogenicity test, the sequence of ribosomal DNA-ITS, the pathogen was identified as Alternaria tenuissima (Kunze) Wiltshire. This is the first report that this fungus infects A. lancea.     

江西甘蔗花叶病病原的分子鉴定

 Sugarcane mosaic disease, caused by Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV), Maize dwarf mosaic virus (MDMV) or Johnsongrass mosaic virus (JGMV) in Potyvirus, is one of the most important viral diseases of sugarcane. In the study, four primer pairs specific to SCMV, SrMV, MDMV and JGMV, respectively, were designed and used to detect 29 sugarcane leaf mosaic samples collected from 9 locations in Jiangxi province. The representative RT-PCR products were sequenced. The results showed that 22 samples were infected by SCMV, three by SrMV, and four were mix-infected by SCMV and SrMV. MDMV or JGMV were not identified in all samples. The result indicates that SCMV is the major pathogen of sugarcane mosaic disease in Jiangxi province, and SrMV is also a pathogen for the disease.     

黑松感染松材线虫后几种有机酸含量的变化

 Changes of benzoic acid, phenylacetic acid and salicylic acid contents in stem of 3-4 year old Pinus thunbergii inoculated with Bursaphelenchus xylophilus were studied by HPLC. The results showed that after nematode infection, contents of benzoic acid and salicylic acid in the stem of Pinus thunbergii increased gradually and then decreased when serious disease occurred, while content of phenylacetic acid increased at early stage and decreased at later stage of the disease. The role of benzoic acid, pbenylacetic acid and salicylic acid during the development of the disease was discussed.     

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.     

上海地区草莓炭疽病病原鉴定

 Seventeen isolates of strawberry anthracnose were obtained from Shanghai suburb. According to the temperature test for mycelial growth, these isolates were divided into two groups:one was strain CMf-04 with optimal temperature of 24℃, the other was including 16 strains with optimal temperature of 28℃, and most of which could produce sexual stage on PSA media, e.g. QPg-961. Conidia of CMf-04 were hyaline, unicellular, straight and fusiform, (12.1-16.4) μm×(3.6-5.4) μm. Conidia of QPg-961 were hyaline, unicellular and ovoid to oblong, (13.0-19.7)μm×(4.1-7.3) μm. On basis of morphologcal, biological characteristics and the sequences of ribosome rDNA ITS, isolate CMf-04 from the strawberry rotten fruits was identified as Colletotrichum acutatum; while all the other isolates from the diseased leaf stalks, runners and root crowns at strawberry plantlet propagation stage were belonged to Colletotrichum gloeosporioides. It proved that C. gloeosporioides was the main pathogen of the strawberry anthracnose in summer strawberry propagation fields in Shanghai and it is of significance for the breeding of resistant strawberry and its control.     

甘薯茎腐病症状及其病原鉴定

 甘薯茎腐病是危害甘薯的一种严重病害,甘薯茎、叶柄、叶片和块根均可被害。该病典型症状是茎基部发黑和变软腐烂,叶发黄,茎和块根维管束黑褐色,引起块根腐烂、有臭味。通过对甘薯茎腐病典型症状样本的采集、病原菌的分离和纯化以及致病性测定,明确该病害是一种细菌病害。通过对甘薯茎腐病菌的菌体形态和培养特性观察发现,病原菌是革兰氏阴性细菌,菌体短杆状,大小约为2.36 μm×0.4 μm, 周生鞭毛,可在烟草上激发过敏性反应(HR)。Biolog测定、脂肪酸分析、16S rDNA序列分析、MALDI-TOF质谱鉴定和8个看家基因(dnaX、rplB、fusA、gapA、gyrA、purA、recA和rpoS)的序列系统发育分析,发现该病原菌与达旦提狄克氏菌Dickeya dadantii高度一致。这些结果说明,浙江省发生的小番薯病害是甘薯茎腐病,病原为D. dadantii。     

贵州省余庆县茶褐枯病病原菌的鉴定

为鉴定引起茶褐枯病的病原菌,本研究对病原菌进行分离、纯化和培养,通过柯赫氏法则验证菌株的致病性,并观察病原菌的形态特征,依据病原菌rDNA-ITS、ACT、CAL和TUB2基因进行多基因系统发育分析。结果显示:病原菌分生孢子呈淡蓝色,表面光滑,无隔膜,圆柱状,两端钝或向底部变窄,水滴状斑点,大小为(11.7~29.5)μm×(3.9~7.7)μm,平均为(19.4±4.4)μm×(5.4±0.8)μm,分生孢子梗形成于气生菌丝上,透明,具有隔膜;附着胞为棒状等不规则形状,颜色呈棕色到深棕色,单生。基于病原菌形态学鉴定和多基因系统发育分析结果,将病原菌确定为山茶刺盘孢Colletotrichum camelliae。     

洛阳牡丹新病害—柱枝孢叶斑病

为了明确河南省洛阳地区牡丹叶部一种新病害的病原种类,对采自田间的典型症状叶片进行了常规组织分离,对单孢菌株进行了形态鉴定、rDNA ITS序列分析及致病性测定.结果表明,病原菌在PDA培养基上菌落初期白色绒毛状,后期红褐色.分生孢子梗通常呈扫帚状,有2～3个分支,末端膨大呈泡囊状.分生孢子直棒状,两端钝圆,有0～1个隔膜,大小为(38.4～86.4)μm× (4.6～5.9)μm,平均60.1 μm×5.2 μm.离体叶片与活体植株接种结果表明,该菌均能侵染牡丹叶片并引起与田间相同的症状.据此将分离物鉴定为Cylindrocladium canadense,将该病害命名为牡丹柱枝孢叶斑病.     

进境美国大豆中大豆茎褐腐病菌的截获

 从进境的美国大豆豆秆样品中分离到2株疑似大豆茎褐腐病菌Phialophora gregata的分离物247-8和8300-5,2株分离物在PGM培养基上菌落圆形,边缘规则,白色至暗褐色,表面隆起,粗糙,轮纹状。分生孢子卵形至椭圆形,无色,平滑,单胞,平均大小4.3 μm×1.9 μm。分生孢子梗具有瓶梗状结构,无色,无隔膜或有隔膜,大小(5~16)μm×(2~3) μm,呈桶型或长颈瓶型。特异性引物BSRIGS1/2、BSR1/2和Pgl/4分别扩增分离物247-8的DNA得到预期1 022 bp、483 bp和499 bp的产物;分离物8300-5的DNA经PCR扩增分别得到834 bp、483 bp和499 bp的预期条带。2株分离物的ITS区序列完全一致,与GenBank中大豆茎褐腐病菌(登录号AB190396、DQ459387、DQ459386和AF132804)的序列相似性为100%。人工接种大豆幼嫩植株茎基部均产生大豆茎褐腐病菌的典型症状。根据分离物形态特征、PCR检测、序列分析以及致病性测试结果,将进境美国大豆样品中的分离物247-8和8300-5鉴定为大豆茎褐腐病菌P. gregata。     

壶瓶枣褐斑病病原菌的鉴定

 近几年来,山西红枣发生了1种严重的果实病害,症状表现为果顶或果肩部位形成红褐色的病斑。本研究以壶瓶枣为材料,对病菌进行分离。通过室内和田间致病性测定以及人工接种后再分离病菌,证明编号为CN535的真菌菌株为该病的致病菌。该病菌在PDA上7d菌落直径达69.2~73.5mm,基内菌丝和气生菌丝均发达,具明显的浅灰与墨绿色的同心轮纹;分生孢子单生或短链生,具纵横隔膜和短喙,大小为(22.5~40.0)μm×(8.0~13.5)μm,为典型的Alternaria属真菌特征。其rDNAITS序列分析结果表明该菌与A. alternata、A. tenuissima、A. longipes、A. mali和A. citri的同源性均为100%。用2对链格孢菌的专用引物AAF₂/AAR3和Aalt-F/Aalt-R分别扩增出相对应的341和450bp的片段。综合形态特征和分子分析结果,确定壶瓶枣褐斑病的病原菌为A. alternata (Fries) Keissler。     

西葫芦根腐和茎基腐病新病原-露湿拟漆斑菌Paramyrothecium roridum

 2013年12月,甘肃省白银市水川镇日光温室中的西葫芦发生了严重的根腐和茎基腐,部分棚室病株率达50%,从病根和病茎上分离得到拟漆斑菌属真菌3株,病株分出率27.3%。采用胚根和茎基部接种法测定了菌株FG-62对西葫芦的致病性:茎基部接种后27 d,植株开始出现凋萎;接种后40 d,两种接种法的西葫芦苗均呈现严重根腐和茎基腐症状,茎基部接种的西葫芦凋萎株率达30%;从病根和病茎上均可再分离出原接种菌。菌株FG-62在PDA平板上25℃培养14 d,产生大量墨绿色至黑色分生孢子座,分生孢子无色至淡榄黑色,单胞,杆状或腰鼓状,两端钝圆,大小为(7.04~9.15)μm ×(1.97~2.46)μm,聚集的分生孢子呈黑色。BLASTn分析结果显示,菌株FG-62(GenBank 登录号 MK252098)的rDNA-ITS序列与露湿拟漆斑菌Paramyrothecium roridum分离物E-469 (GenBank 登录号KY582183.1)和CBS 357.89(源自模式材料,GenBank 登录号NR_145077.1)的序列相似性分别达99.65%和96.83%。依据病原菌形态学和rDNA-ITS序列,将其鉴定为露湿拟漆斑菌P. roridum (Basionym:Myrothecium roridum)。这是露湿拟漆斑菌引起西葫芦根腐和茎基腐的首次报道。     

进境意大利苹果苗上葡萄茎枯病菌的截获鉴定

The isolate ZM40-1 was isolated on Mallus sp. imported from Italy in Ningbo port traditional PDA method. The isolate grew well on three kind of medium, including PDA, MEA and OA, producing mostly little aerial mycelium and abunt pycnidia. The pycnidia were globose or subglobose, 36.4-191.8(87.2) μm in diameter and conidia were variable in shape, mostly ovoid-ellipsoidal, single cell, sometimes curved, 3.3-6.2(5.1)μm ×1.9-3.1(2.7) μm in diameter and hyaline. Chlamydospores were mostly multicellular, solitary or in chains, brown and 18.0-48.0(35.2) μm×7.4-18.7(13.8) μm in size. To compare the isolate sequences (ITS, 28S, ACT and TUB) with the identity of respestive sequence of Phoma glomerata from NCBI GenBank databases by blastn method, the isolate DNA was amplified and sequenced by universal primers. Analysis of these sequences with the related sequences deposited in the NCBI database showed that these sequence had 100% identities, respectively. Pathogenicity tests showed that the isolate didn’t infect stem of Mallus sp.. However, the fruit and leaf were susceptible to P. glomerata. Based on morphological characteristics, molecular and pathogenicity test results, the isolate ZM40-1 was identified as Phoma glomerata (Corda) Wollenweber & Hochapfel. To our know-ledge, this is the first report of interception and identification of P. glomerata in China.     

Characterization of a New Subgroup of Rhizoctonia solani Anastomosis Group 1 (AG-1-ID), Causal Agent of a Necrotic Leaf Spot on Coffee

ABSTRACT A new foliar disease on coffee leaves was observed in Mindanao, Philippines, in 1996. The symptoms appeared as large circular or irregularly shaped necrotic areas with small circular necrotic spots (1 mm or less in diameter) usually found around the periphery of the large necrotic areas. Rhizoctonia solani was consistently isolated from these diseased coffee leaves. Isolates obtained were multinucleate (3 to 12 nuclei per hyphal cell), had an optimum temperature for hyphal growth at 25 degrees C, prototrophic for thiamine, and anastomosed with tester isolates belonging to R. solani anastomosis group 1 (AG-1). Mature cultures on potato dextrose agar (PDA) were light to dark brown. Sclerotia, light brown to brown, were formed on the surface of PDA and covered the whole mature colony culture. Individual sclerotia often aggregated into large clumps (3 to 8 mm in diameter) and their color was brown to dark brown. In pathogenicity tests, isolates from coffee caused necrotic symptoms on coffee leaves, whereas isolates of AG-1-IA (not isolated from coffee), 1-IB, and 1-IC did not. The results of analyses of restriction fragment length polymorphism of ribosomal DNA internal transcribed spacer, random amplified polymorphism DNA, and fatty acid profiles showed that R. solani isolates from coffee are a population of AG-1 different from AG-1-IA, 1-IB, and 1-IC. These results suggest that R. solani isolates from coffee represent a new subgroup distinct from AG-1-IA, 1-IB, and 1-IC. A new subgroup ID (AG-1-ID) is proposed.     

新病害—山核桃果实黑斑病病原菌的鉴定

2007年以来,浙江临安、淳安、桐庐和安徽部分地区山核桃主产区出现了一种果实新病害——山核桃果实黑斑病,该病严重影响山核桃果实的产量和品质。本研究从采集的病果中分离得到了一种真菌,离体幼果接种的症状与田间相似。病原菌在PDA培养基上形成白色轮纹状菌落,分生孢子长梭形,直或弯曲,(22.6～29.9)μm×(6.1～9.0)μm,5个细胞,中间3个有色孢(上部2个为黑褐色、下部1个为淡橄榄色),孢子顶生2～3根附属丝、多为3根。根据该病原菌的培养和形态特征及其ITS序列,将其鉴定为小孢拟盘多毛孢(Pestalotiopsis microspora)。     

湖南芷江辣椒上一种新炭疽病的病原鉴定

 2009 年8 月湖南省芷江县线果型辣椒品种红秀2003 未成熟果实上发生了一种新炭疽病。典型病斑长椭圆状,其中央呈成片黄褐色粉末,外围粉红色小点呈同心圆排列,边缘水渍状。8个分离菌株（HNZJ001 HNZJ008）培养时菌落初呈白色,渐变为浅红色,后期加深, 具明显灰黑色同心轮纹。分生孢子盘无刚毛, 分生孢子单胞,大小为15. 8 μm × 4. 1 μm,含2～7 个油球,一端稍尖。分离菌株HNZJ001 针刺接种,在离体的成熟果和未成熟果上均产生病斑,而作为对照的胶孢炭疽菌Collectotrichum gloeosporioides菌株LSQ1 不能侵染未成熟果。核糖体RNA 基因内转录间隔区(ITS)的PCR 产物经〖JP2〗测序后做BLAST 分析,结果表明该菌与尖孢炭疽菌C. acutatum(有性阶段为尖孢小丛壳Glomerella acutata)的ITS 序列100% 相同,系统进化分析显示置信度高达100%,据此确定该病原为尖孢炭疽菌。这是国内辣椒上尖孢炭疽菌的首次报道。