牛蒡根际土壤致害菌Fusarium solani分离鉴定

目的：探索牛蒡根际镰刀菌与牛蒡之间的相互关系。方法：从全国30个地区采集牛蒡根际土壤样品,进行了根际土壤真菌数量和群落的生态学研究,测定镰刀菌发酵液对牛蒡幼苗和牛蒡子萌发的影响,并对其中毒性最强的两株镰刀菌F130和F131进行了形态学和分子生物学的鉴定。结果：镰刀菌为牛蒡根际的最优势类群,贡献率为34.297%,其次为木霉,贡献率为22.519%;绝大多数镰刀菌对牛蒡有明显的毒性作用,其中F130和F131被鉴定为Fusarium solani。结论：Fusarium solani是牛蒡根际土壤中的致害菌。     

临床常见镰刀菌的鉴别

目的从分子生物学角度寻找一种快速准确鉴定临床常见镰刀菌的方法。方法将受试镰刀菌接种于PDA培养基,观察其菌落及镜下形态,在此基础上PCR扩增受试镰刀菌的rDNA ITS并测其序列,在GenBank核酸序列数据库进行同源序列搜索及分析。选择限制性内切酶Dra Ⅱ和Cfr13 Ⅰ进行RFLP。设计了茄病镰刀菌的种特异性引物Sol1、Sol2,初步验证其特异性。结果形态学鉴定结果显示,茄病镰刀菌所占比例最高,除2株串珠镰刀菌外,其余镰刀菌ITS序列分析的结果与形态学鉴定结果一致。茄病、层生和串珠镰刀菌的Dra Ⅱ、Cfr13 I酶切带形互不相同。用Sol1、Sol2扩增受试菌的rDNA ITS,只有茄病镰刀菌为阳性。结论rDNA ITS序列测定及其PCR-RFLP可用于初步鉴别几种临床常见镰刀菌,合适的种特异性引物可以初步快速鉴定茄病镰刀菌。     

Identification, pathogenicity and comparative virulence of Fusarium spp. associated with insect-damaged, diseased Centaurea spp. in Europe

Fusarium spp. isolated from insect-infested, diseased Centaurea diffusa and Centaurea maculosa in Europe were assessed for pathogenicity to North American plants of their respective original hosts: either C. diffusa or C. maculosa. Of the ten isolates of Fusarium spp. isolated from diseased Centaurea spp. in the Caucasus region of Russia and eastern Europe, all caused one or more disease symptoms or reductions in fresh weight of North American accessions of their original host species. In three instances, these reductions were statistically significant (p = 0.05). Symptoms included overall stunting, root lesions, and crown rot. Reductions in fresh weight of C. diffusa ranged from 17–78%, and C. maculosa exhibited reductions of 18–82%. The pathogenic cultures were identified as F. solani, F. tricinctum and F. oxysporum. Six of seven other cultures were identified as F. oxysporum, and one as F. tricinctum. It was concluded that further screening of a larger set of isolates of foreign Fusarium spp. under quarantine conditions stateside or in limited USDA-ARS overseas facilities is justified and promising.     

Molecular Identification,Mycotoxin Production and Comparative Pathogenicity of Fusarium temperatum Isolated from Maize in China

A recently isolated Fusarium population from maize in Belgium was identified as a new species, Fusarium temperatum. From a survey of Fusarium species associated with maize ear rot in nineteen provinces in 2009 in China, ten strains isolated from Guizhou and Hubei provinces were identified as F. temperatum. Morphological and molecular phylogenetic analyses based on the DNA sequences of individual translation elongation factor 1‐alpha and β‐tubulin genes revealed that the recovered isolates produced macroconidia typical of four‐septate with a foot‐shaped basal cell and belonged to F. temperatum that is distinctly different from its most closely related species F. subglutinans and others within Gibberella fujikuroi complex species from maize. All the strains from this newly isolated species were able to infect maize and wheat in field, with higher pathogenicity on maize. Mycotoxin determination of maize grains infected by the strains under natural field condition by ultra‐high‐performance liquid chromatography–tandem mass spectrometry and gas chromatography–mass spectrometry analyses showed that among fifteen mycotoxins assayed, two mycotoxins fumonisin B₁ and B₂ ranging from 9.26 to 166.89 μg/g were detected, with massively more FB₂ mycotoxin (2.8‐ to 108.8‐fold) than FB₁. This mycotoxin production profile is different from that of the Belgian population in which only fumonisin B₁ was barely detected in one of eleven strains assayed. Comparative analyses of the F. temperatum and F. subglutinans strains showed that the highest fumonisin producers were present among the F. temperatum population, which were also the most pathogenic to maize. These results suggested a need for proper monitoring and controlling this species in the relevant maize‐growing regions.     

滑桃树内生真菌Fusarium sp.1RGa-1b中萘醌类代谢产物及其抗菌活性研究

从滑桃树内生真菌Fusarium sp．（1RGa—1b）的发酵代谢产物中分离得到6个一系列的萘醌类色素化合物,通过波谱分析将其结构鉴定为：3-methylether-fusarubin（1）,anhydrofusarubin（2）,2-aeetonyl-3-methyl-5-hydro—gen-7-methoxy—naphthazarin（3）,2-acetonyl-3-methyl-7-methoxy-8-hydrogen—naphthazarin（4）,2-acetonyl-3-methyl-7-methoxy—naphthazarin（5）,2-isopropanol-3-methyl-7-methoxy-naphthazafin（6）。利用纸片扩散法对这些化合物的抗细菌及抗真菌活性进行了初步测试,实验结果表明：化合物3和4具有弱的抗金黄色葡萄球菌的活性。     

甘肃大葱贮藏期镰孢菌腐烂病病原鉴定

【目的】大葱在贮藏期频繁发生镰孢菌腐烂病,损失严重。明确该病害病原种类对病害防治具有重要意义。【方法】利用组织分离法对采集自甘肃省兰州市(区)蔬菜市场的16份大葱贮藏期镰孢菌腐烂病病样进行病原物的分离、纯化培养,经单孢分离后根据形态学特征,再结合r DNA-ITS、EF-1a(tef)基因序列分析的方法进行鉴定。【结果】共分离得到80株镰孢菌,经鉴定分属3个种,即层出镰孢菌(Fusarium proliferatum)、尖孢镰孢菌(F.oxysporum)和燕麦镰孢菌(F.avenaceum),其中层出镰孢菌为大葱镰孢菌腐烂病的优势致病菌,分离频率为52.50%。对兰州白葱不同部位进行致病性测定,结果表明层出镰孢菌对大葱鳞茎的致病力最强,而燕麦镰孢菌对大葱鳞茎的致病力最弱。【结论】3种镰孢菌作为该病害的病原,属国内首次报道。     

Characterization of Fusarium spp. associated with pineapple fruit rot and leaf spot in Peninsular Malaysia

Pineapple (Ananas comosus) is one the important fruit crops planted in Malaysia, and this study was conducted to determine Fusarium spp. associated with diseases of the fruit crop as Fusarium is prevalent in tropical countries. Our objective was to identify and characterize Fusarium spp. associated with pineapple fruit rot and leaf spot mainly found on the fruits and leaves in Peninsular Malaysia. Fusarium isolates (n = 108) associated with pineapple fruit rot and leaf spot were characterized by morphological, molecular and phylogenetic analyses, a mating study and pathogenicity testing. TEF‐1α sequence analysis identified Fusarium proliferatum, Fusarium verticillioides, Fusarium sacchari and Fusarium sp. Mating was successful only between tester strains of F. proliferatum and F. verticillioides. Sexual crosses with standard tester strains showed that 82 isolates of F. proliferatum produced fertile crosses with mating population D (Gibberella intermedia) and three isolates of F. verticillioides were fertile with the tester strain of mating population A (Gibberella moniliformis). All isolates were pathogenic, causing pineapple fruit rot and leaf spot, thus fulfilling Koch's postulates.     

Evaluation of Streptomyces spp. and Bacillus spp. for biocontrol of Fusarium wilt in chickpea (Cicer arietinum L.)

A study was carried out to test direct and indirect antagonistic effect against Fusarium wilt, caused by Fusarium oxysporum f. sp. ciceri (FOC), and plant growth-promoting (PGP) traits of bacteria isolated from rhizosphere soils of chickpea (Cicer arietinum L.). A total of 40 bacterial isolates were tested for their antagonistic activity against FOC and of which 10 were found to have strong antagonistic potential. These were found to be Streptomyces spp. (five isolates) and Bacillus spp. (five isolates) in the morphological and biochemical characterisation and 16S rDNA analysis. Under both greenhouse and wilt sick field conditions, the selected Streptomyces and Bacillus isolates reduced disease incidence and delayed expression of symptoms of disease, over the non-inoculated control. The PGP ability of the isolates such as nodule number, nodule weight, shoot weight, root weight, grain yield and stover yield were also demonstrated under greenhouse and field conditions over the non-inoculated control. Among the ten isolates, Streptomyces sp. AC-19 and Bacillus sp. BS-20 were found to have more potential for biocontrol of FOC and PGP in chickpea. This investigation indicates that the selected Streptomyces and Bacillus isolates have the potential to control Fusarium wilt disease and to promote plant growth in chickpea.     

泽漆营养器官发育解剖学研究

采用石蜡切片法、半薄切片法对泽漆营养器官的发育过程进行了观察,同时对3种器官中乳汁管的分布和大小进行了分析。结果表明:泽漆根的发育类似于草本双子叶植物根的一般发育规律。初生木质部为三原型。茎的初生结构由表皮、皮层、维管束环和髓构成,其髓中有空腔,而茎的次生生长过程中维管形成层的活动短暂,仅产生少量次生维管组织,不形成周皮。叶的发育包括原分生组织、初生分生组织和成熟结构3个阶段,属于异面叶结构。泽漆乳汁管主要分布在维管束韧皮部的外侧。在3种器官中,乳汁管直径差异较大,依次为根>茎>叶。     

Aggressiveness spectrum and genetic variability of Fusarium spp. on rice and wheat varieties

Abstract

A total of 106 Fusarium spp. were isolated from infected roots and soil samples of wheat and rice. Of the 106 isolates, 32 from wheat, and 74 from rice, were isolated. Six Fusarium spp. (F. oxysporum, F. moniliforme, F. poae, F. graminearum, F. tricinctum and F. equiseti) were identified at specie level. In aggressiveness tests Fusarium spp. root rot causing fungi were screened out into different aggressiveness classes according to disease severity scales. The aggressiveness of Fusarium spp. was studied on wheat varieties (Inqalab-91 and chakwal-86) and on rice varieties (Basmati-385 and IRRI-6) under controlled conditions. The overall total number of aggressive isolates was higher in rice than in wheat. However, the percentage of severely aggressive isolates was high in wheat, whereas the percentage of moderately and slightly aggressiveness isolates was high in rice. In rice, five isolates were non-aggressive and on wheat 17 were non-aggressive. Random Amplified Polymorphism DNAs (RAPDs) were used to study the polymorphism and genetic variations within the population of Fusarium spp. that established to study correlation between taxonomical and genetical characters of fungi. Five random primers were used P1 (5′-AGGAGGACCC-3′), P2 (5′-ACGAGGGACT-3′), PE7 (5′-AGATGCAGCC-3′), P14 (5′-CCACAGCACG-3′) and PE20 (5′-AACGGTGACC-3′). Each of the 10-mer primers produced results based on the respective banding patterns they generated in present investigations. Primers distinguished the F. oxysporum, F. moniliforme, F. graminearum, F. tricinctum, F. poa and F. equiseti. All the tested primers yielded amplification products, and that were reproducible. Although there was some intraspecific variation with primers, some strains were similar and some were different in banding pattern. In F. oxysporum, F. moniliforme, F. graminearum, F. tricinctum, F. poa and F. equiseti were seen clustered close to one another but each primer separated them unambiguously. All primer (P1, P2, P14, PE7 and PE20) combination produced 62 bands. All primers have shown interspecific and intraspecific variations in banding patterns.     

Molecular Identification and Genetic Diversity of Fusarium species Associated with Onion Fields in Turkey

To identify Fusarium species associated with diseases of root and basal plate of onion, surveys were conducted in seven provinces of Turkey in 2007. Samplings were performed in 223 fields, and 332 isolates belonging to 7 Fusarium spp. were obtained. The isolates were identified as F. oxysporum, F. solani, F. acuminatum, F. equiseti, F. proliferatum, F. redolens, and F. culmorum based on morphological and cultural characteristics. Also, species‐specific primers were used to confirm the identity of Fusarium species. F. oxysporum was the most commonly isolated species, comprising 66.57% of the total Fusarium species. F. redolens was identified for the first time in onion‐growing areas of Turkey. Selected isolates of each species were evaluated for their aggressiveness on onion plant. F. oxysporum, F. solani, F. acuminatum, F. proliferatum, and F. redolens were highly pathogenic, causing severe damping‐off on onion plants cv. Texas Early Grano. Inter‐simple sequence repeats (ISSR) markers revealed a high degree of intra‐ and interspecific polymorphisms among Fusarium spp.     

安徽产大戟属药用植物资源及其生物活性

对安徽产大戟属药用植物的资源状况及其生物活性进行了综述。安徽产大戟属药用植物约有9种,具有抗肿瘤、抗菌、抗氧化等生物活性,有些具有一定的毒性。     

Race Distribution, Vegetative Compatibility and Pathogenicity of Fusarium oxysporum f. sp. melonis Isolates in Greece

Races and vegetative compatibility groups (VCGs) in Greek isolates of Fusarium oxysporum f. sp. melonis(Fom) were characterized. Three races (0, 2 and 1–2) among 12 isolates tested and two VCGs among 19 isolates tested, were identified. Race 1–2 was the most common and race 1 was not detected. One widespread VCG corresponded to a VCG previously reported from Israel (coded 0138), and included seven isolates of races 0 and 1–2. The other VCG, which was unclassified, included four isolates of races 0, 2 and 1–2. The latter VCG was detected only in a specific melon‐growing location of Evros. The remaining eight isolates tested for VCG did not show positive reactions with other isolates, with each other or with the testers of VCGs 0135 or 0138, although they produced complementary mutants. Using two inoculation methods, the local cv. ‘Golden Head’ was found susceptible to all known Fom races, and especially to race 1–2. These results show the presence of more than one VCG and the widespread distribution of the race 1–2, in Greece.     

Studies on the transmission of some Fusarium spp. to potato progeny tubers from mother plants and its biological control

Fusarium spp. attack potato roots causing root-rot, damping-off and wilt disease in Assuit Governorate. Forty-five Fusarium isolates were isolated from F. nygamai, F. acutatum, F. solani, F. proliferatum, F. subglutinans, and F. oxysporum. Isolates were tested for their pathogenic capability on Burn potato variety during growing season 2007/2008. Isolates infect potato plants causing either damping-off or wilt symptoms. Isolates varied in their virulence. Role of potato tuber seed in the transmission of the causal pathogen to daughter using Electrophoresis. Protein profiles of the tested isolates divided into four sub-clusters at similarity levels 93.79, 91.55 and 92.62% while isolate of Fusarium profile No. 11 formed separate sub-clusters at similarity level 69.79%. F. nygamai and F. solani were notable exception because profile No. 4 of F. nygamai from roots and profile No. 4 from sprouts were almost identical (similarity level 96.81%); similarity level between profile No. 8 from roots and profile no/8 from sprouts was 95.44%. Results prove that F. nygamai and F. solani are potato tuber seed-borne fungus. T. harzianum, T. viride, T. longibrachiatum, G. virens and E. nigrum or its filtrate inhibited the growth of F. nygamai, F. acutatum, F. solani, F. proliferatum, F. subglutinans and F. oxysporum. The formulation of T. harzianum, T. longibrachiatum and G. virens against tested pathogenic fungi reduce disease incidence under greenhouse conditions.     

一品红苞片花色素的分离及初步鉴定

用紫外-可见光分光光度计、高效液相色谱（HPLC）和质谱（MS）技术对一品红（Euphorbia pulcherrima）红色苞片中的花色素提取液进行了初步鉴定.一品红花色素的甲醇溶液分别在270、340和520 nm处有3个吸收峰;在440 nm吸光度与可见光最大吸收波长520 nm吸光度的比值为0.29;花色素的甲醇溶液中加入AlCl3后发生红移,再加入HCl后发生蓝移;色素溶液在紫外光下无荧光;色素样品经液相色谱分离后在270 nm检测有5个比较明显的吸收峰;质谱中得到595、611、381、571和589等对应的分子离子峰;花色素酸解液高效液相色谱图谱和鼠李糖、葡萄糖的出峰时间一致.由这些结果可推断一品红花色素样品中主要含有5种组分：矢车菊花色素芸香苷、飞燕草花色素芸香苷、飞燕草花色素苯甲酰基葡糖苷、矢车菊花色素苯甲酰基葡糖苷和一种未知成分.     

A Branch-inducing Phytoplasma in Euphorbia pulcherrima is Associated with Changes in Expression of Host Genes

Phytoplasma infection causes a desirable branching phenotype in the ornamental plant Euphorbia pulcherrima by releasing apical dominance . Four E. pulcherrima genes specifically regulated during phytoplasma infection were identified using a combination of differential display of cDNA-polymerase chain reaction (PCR) products and microarray analysis. According to BLAST searches the possible functions of identified genes included a histidine-containing phosphotransmitter, an α-expansin, a protein with similarity to the gibberellin-regulated GAST-1 and a protein with similarity to an Arabidopsis thaliana protein with unknown function.     

Pathogenic Variation of Fusarium Isolates Associated with Head Blight of Wheat in Australia

This paper examines the level of pathogenic diversity in Australian Fusarium pseudograminearum and Fusarium graminearum isolates for head blight from the assessment of 51 wheat germplasm lines, barley, triticale, rye, maize and sorghum plants. A set of nine putative wheat differentials were selected and assessed with 10 F. graminearum and 12 F. pseudograminearum isolates. Isolates of both species were pathogenic on all the wheat germplasm lines, barley triticale and rye. The isolates differed largely in a quantitative way with only small differential effects and were statistically demarcated into three pathogenicity groups: low, intermediate and high. Such distribution patterns suggest that wheat germplasm lines employ different resistance mechanisms to each group of isolates and the three pathogenicity groups may have different mechanisms controlling pathogenicity. The aggressiveness of F. graminearum and F. pseudograminearum isolates on the wheat germplasm lines were marginally correlated (r = 0.40). Durum wheats were ranked as the most susceptible while Sumai 3, Ituo Komugi, Sotome A, Sotome and Nobeokabouzu komugi were consistently grouped as resistant by both species. These findings reiterate the need to consider pathogen variability in the screening, selection and improvement of resistance to head blight in wheat.     

Identification of Protease from Euphorbia amygdaloides Latex and its Use in Cheese Production

Abstract

In this research, protease enzyme was purified and characterized from milk of Euphorbia amygdaloides. (NH₄)₂SO₄ fractionation and CM‐cellulose ion exchange chromatography methods were used for purification of the enzyme. The optimum pH value was determined to be 5, and the optimum temperature was determined to be 60°C. The V_max and K_M values at optimum pH and 25°C were calculated by means of Linewearver‐Burk graphs as 0.27 mg/L min^?1 and 16 mM, respectively. The purification degree was controlled by using SDS‐PAGE and molecular weight was found to be 26 kD. The molecular weight of the enzyme was determined as 54 kD by gel filtration chromatography. These results show that the enzyme has two subunits.

In the study, it was also researched whether purified and characterized protease can be collapsed to milk. It was determined that protease enzyme can collapse milk and it can be used to produce cheese.     

松材线虫生防细菌的筛选、鉴定及其毒性因子的初步研究

从河南南阳不同农田的植物根部采取土壤样本,共分离获得了198株细菌。通过毒性测试和平板生测从中筛选出松材线虫生防细菌6株,其中NS-3菌株对松材线虫的杀灭活性最高。结合该菌株的形态学、生理学特征及16S rDNA序列分析等结果将该菌株归为芽孢杆菌属,命名为Bacillus sp.strain NS-3。将该细菌液体培养的上清液和上清蛋白粗提物分别处理松材线虫48h后线虫的死亡率分别达到50%和100%;线虫死亡后虫体消解。然而,细菌的上清蛋白粗提物经煮沸变性后,基本丧失了对松材线虫的侵染活性,结果显示细菌Bacillus sp.strain NS-3的杀线虫活性物质主要要存在于细菌培养上清液中,并且为热不稳定性物质。