First report of Fusarium oxysporum species complex infection in zebrafish culturing system

Fusarium oxysporum species complex (FOSC) is a highly diverse fungus. Recently, F. oxysporum infection was identified from zebrafish (Danio rerio) culturing system in Korea. Initially, a rapid whitish smudge was appeared in the water with the fungal blooming on walls of fish tanks. Microscopic studies were conducted on fungal hyphae, colony pigmentation and chlamydospore formation and the presence of macro‐ and microspores confirmed that the isolated fungus as F. oxysporum. Furthermore, isolated F. oxysporum was confirmed by internal transcribed spacer sequencing which matched (100%) to nine F. oxysporum sequences available in GenBank. Experimental hypodermic injection of F. oxysporum into adult zebrafish showed the development of fungal mycelium and pathogenicity similar to signs observed. Histopathologic results revealed a presence of F. oxysporum hyphae in zebrafish muscle. Fusarium oxysporum growth was increased with sea salt in a concentration‐dependent manner. Antifungal susceptibility results revealed that F. oxysporum is resistant to copper sulphate (up to 200 μg mL^?1) and sensitive to nystatin (up to 40 μg mL^?1). This is the first report of FOSC from zebrafish culture system, suggesting it appears as an emerging pathogen, thus posing a significant risk on zebrafish facilities in the world.     

Assessment and selection of fungal antagonists against Rhizoctonia solani

The soil-borne pathogen Rhizoctonia solani Kühn (teleomorph, Thanatephorus cucumeris [A.B. Frank] Donk) is worldwide responsible for serious damage of many economically important agricultural and horticultural crops. Control of Rhizoctonia diseases is difficult because this pathogen survives for many years as sclerotia in soil or as mycelium in organic matter under numerous environmental conditions. Furthermore, the pathogen has an extremely wide host range. To date, no effective con…     

菜豆种子几丁质酶的分离纯化及性质研究

运用硫酸铵分级沉淀与亲和层析技术相结合的方法,分离纯化了菜豆种子中的几丁质酶。ＳＤＳ－聚丙烯酰胺凝胶电脉图谱显示,经亲和层析后的蛋白质样品呈单一谱带,分子质量为３．４６×１０＾４,纯化倍数达４８．８倍,几丁质酶回收率为４７％,酶的最适温度为４５℃,最适ｐＨ值为６．０。纯化菜豆种子几丁质酶对绿色木霉菌生长具有抑制作用。     

菠萝真菌病害研究现状

本文将迄今已报道的５０余种菠萝真菌病害分为心腐、果腐、凋萎及叶斑四类，并对它们的症状、病原、侵染循环、发病条件和防治措施等分别进行了综述。     

广西甘蔗主要真菌病害调查初报

[目的]明确广西蔗区主要真菌病害的发生情况和种类,为甘蔗病害综合防治提供科学依据.[方法]2009~2011年采用随机踏查、种植户随访、资料查询和定点调查等方法对广西蔗区甘蔗真菌病害种类及发生程度进行调查,并采集病害样本,通过病原分离培养鉴定等方法确定真菌病害的种类.[结果]共采集和鉴定出13种主要真菌病害,分别为:黑穗病、凤梨病、梢腐病、锈病、叶焦病、赤腐病、轮斑病、褐条病、褐斑病、虎斑病、白疹病、眼点病、黄点病,其中发生严重并对甘蔗品质和产量影响最大的病害有黑穗病、锈病、梢腐病和凤梨病.[结论]黑穗病仍然是对甘蔗危害最严重的病害,生产中急需选育高抗且综合性状优良的甘蔗品种以替代现有的感病品种.     

Identification of Vibrio parahaemolyticus in Seafood by Multiplex PCR

ABSTRACT

Vibrio parahaemolyticus is a human pathogen frequently found in seafood. Once the seafood is contaminated by V. parahaemolyticus, it can become a vehicle for foodborne illness. The conventional culture methods for detection of V. parahaemolyticus are time-consuming and cannot differentiate pathogenic strains from nonpathogenic ones. In this study, a multiplex polymerase chain reaction (PCR) technique was investigated for detecting tdh, chiA, and toxR of V. parahaemolyticus. The sensitivity of the multiplex PCR was determined by testing 28 strains of V. parahaemolyticus, 15 non-V. parahaemolyticus strains, and fresh seafood spiked with cells of V. parahaemolyticus. All the strains were analyzed for production of thermostable direct hemolysin (TDH) and chitinase. This study showed that both the chiA and toxR are excellent markers for detecting V. parahaemolyticus strains, and a multiplex PCR targeting chiA and tdh genes can be applied to simultaneously detect environmental and pathogenic V. parahaemolyticus.     

Transfer of resistance to race 2 of Plasmodiophora brassicae from Brassica napus to cabbage (B. Oleracea spp. Capitata). IV. A resistant 18-chromosome B1 plant and its B2 progenies

Summary The somatic karyotype and meiotic chromosome behavior were studied in an 18-chromosome B₁ plant derived from backcrossing a triploid (Brassica napus x B. oleracea ssp. capitata) F₁ hybrid to cabbage. It is considered that cabbage chromosomes no. 1 and no. 7 were substituted by two shorter B. napus chromosomes. Meiotic disturbances were more apparent during the late stages of second division. Seed fertility of this plant was largely restored in the second backcrosses with both cabbage and broccoli. 18-chromosome B₂ plants resistant to race 2 of Plasmodiophora brassicae were recovered among the progenies.Contribution no. J. 725 from the Research Station, Research Branch, Agriculture Canada, St-Jean, Québec J3B 6Z8.     

复合木霉制剂防治黄连根腐病及其机理研究

为评价复合木霉制剂对黄连根腐病的防治效果, 并揭示其防病机理, 为黄连根腐病专用微生物农药的研发奠定基础, 本试验将深绿木霉Trichoderma atroviride、长枝木霉T. longibrachiatum、钩状木霉T. hamatum、拟康宁木霉T. koningiopsis等4种木霉配制的复合制剂和尖镰孢Fusarium oxysporum以不同的方式分别施用于黄连, 统计根腐病发生情况, 检测黄连根部防御酶活性, 用高通量测序分析根际土壤真菌群落结构。结果表明, 复合木霉制剂对尖镰孢导致的根腐病具有明显预防效果;复合木霉制剂和尖镰孢分别接种黄连可提高SOD、POD、CAT、PAL、PPO等防御性酶活性, 产生诱导抗性;而它们先后接种黄连可产生强化效应, 从另一个途径提高植株抗病性。复合木霉制剂和尖镰孢都会降低真菌的数量、多样性, 和某些真菌的相对丰度, 而复合木霉制剂的抑菌作用更强烈, 尤其能明显抑制尖镰孢、Ilyonectria sp.等病原真菌的生长, 且能改善土壤真菌群落结构。木霉和尖镰孢都能在土壤中较长期定殖。可见, 复合木霉制剂可以预防尖镰孢导致的黄连根腐病, 防病机理包括诱导黄连植株产生抗性, 接种后再遭受病原菌侵染产生的强化效应, 优化土壤真菌群落结构, 抑制土壤中病原菌等, 且有效期较长。因此复合木霉制剂具有开发为微生物农药防治黄连根腐病的潜力。     

Conjunctival fungal flora in healthy donkeys

OBJECTIVE: To identify and quantify ocular fungi from healthy donkeys living in the center of Italy. ANIMALS STUDIED: One hundred and two Amiata donkeys were examined. PROCEDURES: Conjunctival swabs from both eyes were seeded onto Sabouraud dextrose agar (SDA) and malt extract agar (MEA), and incubated at 25 degrees C over a 10-day period. Filamentous fungi identification was achieved to the genus level; yeast colonies were identified for macro-micromorphologic and physiological characteristics. RESULTS: Eighty-one donkeys out of 102 (79.4%) were positive for fungi; 47/102 (46.1%) had positive cultures from both eyes. Most frequently recovered fungal genera were Aspergillus spp., Penicillium spp., Cladosporium spp., Acremonium spp. Different fungal genera and/or species were recovered from the same donkey in 43 cases (42.1%). Yeasts were isolated from five subjects; the yeasts were never associated with molds. The number of colony forming units (CFU) ranged from 1 to 100. CONCLUSIONS: Aspergillus was the most commonly isolated fungal genus (33%). This result agrees with the findings of similar surveys carried out in horses. There was a remarkable presence of fungi and perfect forms. These observations may be explained by the optimal conditions for presence and development of fungi in the conjunctival fornix microenvironment in Amiata donkeys.     

FDA‐active fungal mycelium and lignin concentrations in some needle and leaf litter types

The concentration of live fungal biomass (FDA mycelium) was investigated in seven chemically very different litter types, i.e. grey alder leaves, green and brown leaves of white birch, green and brown needles of both Scots pine and lodgepole pine. Concentration of FDA mycelium in the litters changed with the season, being low during the dry late summer and relatively higher during the more rainy, wet autumn. During autumns, when moisture was not limiting, lignin concentration and live fungal biomass were negatively related. It was concluded that the concentration of live fungal biomass in litter decreased linearly as the lignin concentration increased and thus also decreased linearly to decomposition level of the litter.