湖北武汉茶树内生真菌多样性及种群结构

为了解武汉地区茶树内生真菌的多样性,从鄂茶1号、鄂茶5号、福鼎大白茶的茎、叶共210个组织块中,分离获得166株内生真菌菌株。结果表明,茶树受内生真菌侵染程度较高,74.29%的组织有内生真菌存在。根据r DNA-ITS系统发育分析,从中分离鉴定内生真菌15属,27个分类单元,主要有链格孢(Alternaria)、葡萄座腔菌(Botryosphaeria)、刺盘孢(Colletotrichum)、间座壳属(Diaporthe)、镰孢霉(Fusarium)、赤霉(Gibberella)、小从壳菌(Glomerella)、球座菌(Guignardia)、新壳梭孢菌(Neofusicoccum)、拟盘多毛孢(Pestalotiopsis)、拟茎点霉(Phomopsis)、格孢腔菌(Pleosporales)、拟青霉(Paecilomyces)、腐霉(Pythium)、丝核菌(Rhizoctonia)和2种未知真菌。根据相对频率,葡萄座腔菌(Botryosphaeria dothidea)、盘长孢状刺盘孢(Colletotrichum gloeosporioides)、芒果球座菌(Guignardia mangiferae)等在茶树中比较常见。不同组织部位、不同品种内生真菌分布及组成存在差异,表现出较丰富的多样性。     

浙江省“浙八味”道地药材真菌病害调查及病原鉴定

通过对浙江省磐安地区"浙八味"药材真菌病害进行病原菌分离和鉴定,采用无菌培养基平板分离技术,从药材植物病叶中分离获得病原真菌,构建真菌ITS系统发育树,对病原菌进行分子水平的分类鉴定,并观察病原菌菌落形态及显微结构和形态学鉴定共获得9种病原真菌,分别为链格孢菌(Alternaria sp.)、尖孢镰刀菌(Fusarium oxysporum)、球毛壳菌(Chaetomium globosum)、绿色木霉菌(Hypocrea virens)、月状旋孢腔菌(Cochliobolus lunatus)、球孢黑孢霉(Nigrospora sphaerica)、木贼镰刀菌(Fusarium equiseti)、束状刺盘孢(Colletotrichum dematium)和茎点霉菌(Phoma sp.)。查阅药用植物病原菌记录并结合科赫法则实验,当地药用植物成为3种病原菌的新寄主,分别为月状旋孢腔菌引起的安徽亳州白芍褐斑病、束状刺盘孢引起的磐安阔叶麦冬炭疽病、球毛壳菌引起的早小洋菊叶枯病。     

板栗贮藏期致腐病原真菌种类鉴定及其侵染特性

从无症和显症的板栗种仁上经组织分离法共分离获得22株真菌,其中16株经鉴定为11个属真菌:短梗霉属(Aureobasidium sp.)、链格孢属(Alternaria sp.)、茎点霉属(Phoma sp.)、青霉属(Penicillium sp.)、聚端孢属(Trichothecium sp.)、壳梭孢属(Fusicoccum sp.)、丝核菌属(Rhizoctonia sp.)、毛霉属(Mucor sp.)、刺盘孢属(Colletotrichum sp.)、葡萄孢属(Botrytis sp.)和镰刀菌属(Fusarium sp.),另有6个未知菌株有待鉴定,链格孢属、镰刀菌属、聚端孢属和壳梭孢属为致病优势菌株。回接试验表明,致腐真菌在板栗有伤时容易侵入种仁引起发病,在板栗无伤时多数菌株不能侵入,个别菌株能侵入,但侵染率低,病情不严重。不同处理对板栗贮藏期防腐试验得出,防腐处理虽然能够清除种子表面的病菌,但不能清除种子内部的病原菌,其防效不明显。     

甘肃豌豆根病的病原菌种类及致病力研究

分离鉴定结果表明,甘肃豌豆根病病原真菌为豌豆丝囊根腐霉(Aphanomyces euteiches Drechs),根串珠霉(Thielaviopsis basicola(Cerk & Br.Ferr.),终极腐霉(Pythium ultimum Trow)尖孢镰刀菌(Fusarium oxysporum Schlecht),丝葚霉B(Papulospora sp. B),腐皮镰刀菌(Fusarium solani(Mart)Sacc.),黑色不产孢菌(Black steile fungus),镰刀菌(Fusarium sp.),丝葚霉A(Papulospora sp.A),丝核菌(Rhizoctonia solani kühn)。10种病原真菌的总侵染株率91.3%,其中豌豆丝囊霉侵染株率62.5%,其余9种病原真菌侵染株率37.3%。分别用豌豆丝囊根腐霉,根串珠霉、终极腐霉、尖抱镰刀菌、丝葚霉B、腐皮镰刀菌、黑色不产孢菌、镰刀菌、丝葚霉A、丝核菌给豌豆植株茎基部接菌,病情指数分别为84.4、61.5、45.0、51.6、80.1、68.3、51.7、50.9、41.6、20.4。植株干重较对照减少依次为56.8%、47.0%、44.6%、36.7%、22.0%、12.2%、20.0%、8.8%、10.2%、24.0%。     

木麻黄内生真菌次生代谢产物及生物活性

【目的】分离和鉴定木麻黄Casuarina equisetifolia枝条和果实中的内生真菌,筛选具有抗菌和抗氧化活性的内生真菌。【方法】采用组织块分离法分离木麻黄枝条和果实中的内生真菌,通过菌落观察和分子生物学相结合的方法对分离到的内生真菌进行鉴定;采用薄层层析-生物自显影法测定木麻黄内生真菌次生代谢产物对细菌的抑制活性,采用多孔板-DPPH显色法测定抗氧化活性。【结果】从木麻黄枝条和果实中共分离鉴定得到12株内生真菌,枝条和果实内生真菌存在明显的差异,相同的菌株只有2株,分别为Cef-1(Pseudofusicoccum sp.)和Cef-7(Pestalotiopsis sp.);12株内生真菌分属于9个不同的属中,分别为Pseudofusicoccum、葡萄座腔菌属Botryosphaeria、拟盘多毛孢属Pestalotiopsis、木霉属Trichoderma、曲霉属Aspergillus、裂菌属Rhytidhysteron、拟茎点霉属Phomopsis、镰刀菌属Fusarium和炭疽菌属Colletotrichum。其中,葡萄座腔菌属种类最多,为木麻黄内生真菌的优势种群,其次是拟盘多毛孢属真菌。抗细菌活性的结果表明,Cef-2(Botryosphaeria sp.)表现出最强的抑制活性,对所有供试细菌的抑菌斑直径均大于10 mm,强于阳性对照硫酸链霉素,Cef-1和Cef-9(Fusarium sp.)对青枯病菌Ralstonia solanacearum也表现出较好的抑制活性。内生真菌Cef-2表现出最好的抗氧化活性,IC50为0.80mg/mL。【结论】木麻黄枝条和果实中均存在内生真菌且均以葡萄座腔菌属为优势种群,2个部位真菌的种类存在明显差异。内生真菌Cef-2表现出最强的抗细菌和抗氧化活性,可作为候选菌株进一步分离和鉴定其活性成分。     

信阳野生枸杞枝栖内生真菌多样性研究

为了解枸杞(Lycium chinense Mill.)枝栖内生真菌菌群多样性及分布规律,通过采样、分离、培养与鉴定,对信阳野生枸杞内生真菌的群落结构及生态分布特点进行了研究。结果显示,内生真菌广泛分布于枸杞健康枝内,定殖率达56.8%。共分离得到真菌717株,产孢真菌归于12个属,大多数属半知菌,少数属子囊菌,其中,拟茎点霉属(Phomopsis)、链格孢属(Alternaria)、镰刀菌属(Fusarium)和刺盘孢属(Colletotrichum)真菌为枸杞枝栖优势真菌,漆斑菌属(Myrothecium)、枝孢属(Cladosporuum)、长蠕孢属(Helminthosporium)、拟茎点霉属(Phomopsis)、壳梭孢属(Fusicoccum)、毛壳菌属(Chaetomium)、木霉属(Trichoderma)为枸杞属(Lycium)植物内生真菌新记录。枸杞生境是影响其枝栖内生真菌多样性的重要因素。     

北京昌平区食用百合根及鳞茎腐烂的病原菌分离与鉴定

【目的】明确引起北京昌平区食用百合根及鳞茎腐烂的病原菌种类。【方法】采用PDA培养基对采集自田间的食用百合腐烂发病的根及鳞茎组织进行病原菌分离纯化,对真菌分离物进行孢子形态观测,结合ITS序列分析和致病性测定,对病原真菌进行鉴定。【结果】从发病组织上共分离纯化得到18株真菌分离物,经鉴定,其中尖孢镰刀菌(Fusarium oxysporum)12株,角担菌属(Ceratobasidium spp.)真菌分离物6株,室内与田间致病性测定结果表明,尖孢镰刀菌(F.oxysporum)为引起百合根及鳞茎腐烂的致病菌。【结论】造成北京昌平地区食用百合根及鳞茎腐烂病的病原菌为尖孢镰刀菌(Fusarium oxysporum)。     

奉新县猕猴桃果实腐烂病病原菌分离鉴定

为明确江西奉新猕猴桃果实腐烂的病原菌种类,对该县猕猴桃烂果进行大量病菌分离,对分离的病菌进行了分子鉴定和致病性测定,结果表明引起奉新猕猴桃烂果的病原菌有6种,分别是葡萄座腔菌(Botryosphaeria dothidea)、富氏葡萄孢盘菌(Botryotinia fuckeliana)、盘多毛孢菌(Pestalotiopsis sp.)、层出镰刀菌(Fusarium proliferatum)、拟茎点霉菌(Phomopsis sp.)和链格孢菌(Alternaria sp.),其中主要是葡萄座腔菌(分出率占83.0％),其次是拟茎点霉菌(分出率占8.9％).致病性测定结果同时表明葡萄座腔菌既可从果面伤口侵入,也可以从果皮直接侵入,其他5种真菌则只能从伤口侵入.研究结果对奉新猕猴桃烂果病害的防治和进一步研究将具有重要的指导意义.     

湛江金银花内生真菌多样性研究

为了解湛江金银花内生真菌的多样性,比较分析不同地区金银花真菌种类差异.采用真菌形态鉴定同时结合真菌ITS序列方法对金银花内生真菌的多样性进行研究.结果从湛江金银花分离鉴定了内生真菌17株,分别属于9个属17个种,其中拟盘多毛孢属Pestalotiopsis为优势属,占分离总株数的29.41％,叶部分离的主要是木霉属Trichoderma和拟茎点霉属Phomopsis,茎部分离的是镰刀菌属Fusarium,花部分离得到的主要是拟盘多毛孢属Pestalotiopsis.不同组织部位的湛江金银花内生真菌在数量和种群组成中存在差异,表现出较丰富的多样性.     

郁金香种球腐烂的真菌病原鉴定

经柯赫氏法则对引起郁金香种球腐烂的主要真菌病原物进行鉴定得出,在天津地区引起郁金香种球腐烂的主要真菌性病原物有;腐霉属(Pythium)、根霉属(Rhizopus)、木霉属(Trichoderma)、丛梗孢属(Momilia)、葡萄孢属(Botrytis)、镰孢霉属(Fusarium)、座坚壳属(Rosellinia)、链格孢属(Siodesnium)和青霉属(Penicillium)等9个属.其中腐霉属分离率为30.95%,根毒属分离率为7.14%,木霉属分离率为4.76%,丛梗孢属分离率为14.28%,葡萄孢属分离率为4.76%,镰孢霉属分离率为11.90%,座坚壳属分离率为7.14%,链格孢属分离率为7.14%,青霉属分离率为11.90%.     

Distribution of Fungi from the Genus <Emphasis Type="Italic">Fusarium</Emphasis> Link. on Cereals

The species composition of fungi from the genus Fusarium was studied, and the frequency of occurrence on cereals was determined. Populations of Fusarium spp. were represented by widespread species F. culmorum, F. heterosporum, F. sporotrichioides, F. oxysporum, F. nivale, F. graminearum, F. avenacеum, F. gibbosum, F. sambucinum, F. moniliforme, etc. The dynamics and frequency of occurrence of Fusarium spp. has made it possible to characterize the state of the species of fungi in a wide range of climatic areas of cereal cultivation in the Russian regions. The prevalence of the genus Fusarium was caused by the cultivars’ susceptibility to micromycetes. The frequency of occurrence of Fusarium species isolated from roots was steady, and, on the ears, it depended on the influence of weather conditions during the growing season of plants. The study of the intraspecific variability of fungi from the genus Fusarium has revealed a significant difference in signs of toxicity and pathogenicity depending on biotic and abiotic factors. More than 50% of strains from the genus Fusarium possessed low pathogenicity but had severe toxicity to wheat seedlings. Most strains of F. sporotrichiodes, F. culmorum, and F. sambucinum were highly pathogenic (from 36.4 to 55.6%) and toxic (from 55.6 to 81.3%). High adaptability to preservation in the soil and on the roots of weeds and crop residues of most crops expressing pathogenic and toxic activity was conductive to the widespread Fusarium spp.     

黑龙江省药用植物根际土壤真菌多样性

为了解黑龙江省药用植物根际土壤真菌的种群结构和区系分布特点,于2010年7月份和10月份,在黑龙江省的伊春、铁力、绥化、哈尔滨、牡丹江和佳木斯6个中药材产区共采集土壤样品220份,所采集的药用植物种类主要有五味子、平贝母、刺五加、党参、防风、柴胡、桔梗、黄芩等14种.经稀释平板法和土壤颗粒平板法分离共获得1016株真菌,经形态鉴定归为35属86种,其中接合菌7属10种,占7.78％;子囊菌1属2种,占0.69％;无性型真菌27属74种,占70.76％,其余20.77％的菌株为不产孢真菌.试验结果表明,黑龙江省药用植物根际土壤真菌的种群多样性丰富,其中青霉属Penicillium、曲霉属Aspergillus、木霉属Trichoderma、镰孢菌属Fusarium是优势种群,粘帚霉属Gliocladium、金孢属Chrysosporium、毛霉属Mucor、枝孢属Cladosporium、枝顶孢属Acremonium、根霉属Rhizopus是亚优势种群.不同药用植物根际土壤真菌区系的结构和组成存在一定的差异.除无孢类群外,青霉属Penicillium、曲霉属Aspergillus、木霉属Trichoderma和镰孢菌属Fusarium是14种药用植物根际土壤真菌的优势菌群.五味子、平贝母和柴胡是黑龙江省种植的主要中药材,它们在6个采样地点间的真菌种群的多样性水平存在差异,其中伊春地区的多样性指数(H’=2.9574)和丰富度指数(R=5.6683)最高,而佳木斯地区的均匀度指数(J=0.9200)最高.不同地区的相似性水平也存在差异,其中牡丹江与绥化的药用植物根际土壤真菌种群组成之间的相似性系数最高(Cj=0.6315),牡丹江与哈尔滨的相似性最低(Cj=0.3704).     

Species Composition of <Emphasis Type="Italic">Fusarium</Emphasis> Fungi Revealed on Spring Barley Crops in Central Russia in 2015–2017

Species composition of Fusarium fungi and the frequency of their occurrence on spring barley crops in the Moscow, Tula, and Vladimir oblasts of Russia have been studied in 2015–2017. Over 700 strains of fungi belonging to 12 species of the genus Fusarium have been isolated into pure culture. The species composition of these fungi in the studied regions includes both common and rare species. Fungal cultures isolated from roots and reproductive organs demonstrated a high uniformity of their species composition that may be explained by a similarity of soil and climatic conditions and by the susceptibility of barley cultivars to soilborne micromycetes. The frequency of occurrence of the fungi on underground parts of plants was rather uniform, while that on the grain depended on the environmental conditions prevailing during the flowering and ripening stages. Among isolated Fusarium strains, 33 isolates with stable morphological and cultural characteristics have been deposited into the State Collection of Plant Pathogenic Microorganisms. Strains with the highest pathogenicity and toxicity were recommended for the artificial infection background created during regional trials of barley cultivars for disease resistance.     

Crop biomass and humidity related factors reflect the spatial distribution of phytopathogenic <Emphasis Type="Italic">Fusarium</Emphasis> fungi and their mycotoxins in heterogeneous fields and landscapes

Fusarium head blight (FHB) is a global problem in small-grains agriculture that results in yield losses and, more seriously, produces harmful toxins that enter the food chain. This study builds on previous research identifying within-field humidity as an important factor in infection processes by Fusarium species and its mycotoxin production. Environmental variables describing topographic control of humidity (TWI), soil texture and related moisture by electrical conductivity (ECa), and canopy humidity by density (NDVI) were explored in their relationship to the fungal infection rates, the abundance of trichothecene-producing Fusarium spp. as determined by TRI 6 gene copies and mycotoxin accumulation. Field studies were performed at four field sites in northeastern Germany in 2009 and 2011. In the wet year 2011, a high Fusarium infection rate resulted in a high abundance of trichothecene-producing fungi as well as high concentrations of mycotoxins. Simultaneously, Fusarium spp. inhibited the development of other filamentous fungi. Overall, a very heterogeneous distribution of pathogen infections and mycotoxin concentrations were displayed in each field in each landscape. The NDVI serves as an important predictor of the occurrence of phytopathogenic Fusarium fungi and their mycotoxins in a field and landscape scale. In addition, the ECa reflects the distribution of the most frequently occurring mycotoxin deoxynivalenol within the fields and landscapes. In all cases, TWI was not found to be a significant variable in the models. All in all, the results extend our knowledge about suitable indicators of FHB infection and mycotoxin production within the field.     

土壤真菌对威百亩熏蒸的响应特征

为探明土壤熏蒸后真菌群落的演变特征及其种间关系的变化规律,以揭示熏蒸剂对土壤生态系统的利害关系。选取威百亩作为典型熏蒸剂对连作3年黄瓜的土壤进行熏蒸处理,并采用高通量测序手段检测了各处理在不同时段的真菌群落。与未熏蒸对照处理(NM)相比,Chao1指数在低浓度(LM,50 mg·kg-1)和高浓度威百亩熏蒸处理(HM,100 mg·kg-1)中分别降低了14%(P=0.001)和16%(P=0.005),各处理真菌群落结构的差异也达显著水平。供试土壤中潜在典型病原真菌主要为Gibberella和Fusarium,且受到威百亩熏蒸的显著抑制,尤其在HM处理中,其丰度较NM处理分别降低了95%和53%(P0.05)。而潜在典型有益菌如Talaromyces和Arthrographis展现出与潜在病原菌相反的趋势,且这种趋势在HM处理中更明显。随着培养时间延长,虽然Gibberella和Fusarium在LM处理中展现出抑制-恢复的趋势,但在HM处理中其丰度随时间逐渐降低。Network关联分析结果显示,在NM处理中各功能菌丰度间均为正相关关系,而高浓度威百亩熏蒸后出现了优势菌对潜在病原菌的拮抗作用。综上所述,相比于低浓度威百亩熏蒸,高浓度威百亩不仅有效抑制了土壤中潜在病原真菌的活性,而且还通过调控真菌群落种间关系从而强化了优势菌对潜在病原真菌的拮抗作用,进而间接地增强了部分有益菌的活性。     

有机肥施用量和树龄差异对苹果园土壤真菌群落的影响

为揭示有机肥施用量对不同树龄果园土壤真菌群落的影响,在北京市昌平区选择不同有机肥施用量和种植年限的苹果园,采集0～20cm的土壤样品,利用Illumina Miseq高通量测序平台测定及分析土壤真菌丰富度、群落组成和群落结构,并与土壤理化性质和果实品质进行关联分析。结果表明:1)该苹果园长期施用有机肥,土壤有机质和速效养分(特别是碱解氮)含量增加;2)有机肥施用量相同时,随着树龄增加果园土壤真菌丰富度增加;而有机肥施用量对幼龄果园土壤真菌的丰富度和成龄果园土壤真菌群落的多样性有更多的影响;3)该苹果园土壤真菌包括7个门,其中子囊菌门和担子菌门为优势菌群,并且有机肥施用量使优势菌的占比发生改变,随有机肥施用量的增加,子囊菌门相对丰度增加,而担子菌门相对丰度降低;4)通过RDA分析表明,假霉样真菌属、毛壳菌属和镰刀菌属与果园土壤有机质和速效养分之间存在正相关关系,同时在果实可滴定酸和可溶性糖含量上也有正向作用。综上所述,适量增加有机肥施用量可增加有益真菌组成,从而提高树体长势和果实品质。     

Mycotoxin contamination of reindeer moss

Reindeer moss samples taken in 2009–2010 in northern European Russia (Murmansk oblast, Karelia) are found to be extensively and multiply contaminated with mycotoxins. The possibility of the development on reindeer moss of individual species of toxic fungi belonging to the genera Penicillium, Aspergillus, Alternaria, and Fusarium is discussed.     

Expression Comparisons of Pathogenesis-Related (PR) Genes in Wheat in Response to Infection/Infestation by Fusarium,Yellow dwarf virus (YDV) Aphid-Transmitted and Hessian Fly

Expression profiles of ten pathogenesis-related (PR) genes during plant defense against Fusarium, Yellow dwarf virus (YDV) aphid-transmitted and Hessian fly (Hf) were compared temporally in both resistant and susceptible genotypes following pathogen infection or insect infestation. Quantitative real-time PCR (qRT-PCR) revealed that PR1, PR2, PR3, PR5, PR6, PR8, PR9, and PR15 appeared to be induced or suppressed independently in response to Fusarium, YDV aphid-transmitted or Hf during the interactions. The PR gene(s) essential to defense against one organism may play little or no role in defense against another pathogen or pest, suggesting the alternative mechanisms may be involved in different interactions of wheat-Fusarium, wheat-YDV aphid-transmitted and wheat-Hf. However, strong up- or down-regulation of PR12 and PR14 encoding low molecular membrane acting protein, defensin and lipid transfer protein (LTP), respectively, had been detected after either pathogen infection or insect infestation, therefore showed broad responses to pathogens and insects. It was postulated that low molecular proteins such as defensins and LTPs might play a role in the early stages of pathogenesis in the signaling process that informs plants about the attack from biotic stresses. In addition, a synergistic action between different PR genes might exist in plants to defense certain pathogens and insects on the basis of comprehensive expression profiling of various pathogenesis-related genes revealed by qRT-PCR in this study.     

Morphological,Biochemical and Genetic Analysis of a Brittle Stalk Mutant of Maize Inserted by Mutator

Mutants on stalk strength are essential materials for the studies on the formation of plant cell wall. In this study, a brittle stalk mutant of maize, designated as Bk-x, was screened from a Mutator inserted mutant library. At the germination and early seedling stage, the mutant plants were indistinguishable from the normal ones. However, all of the plant organs were brittle after the 5th-leaf stage and remained brittle throughout the rest of the growing period. Microstructure observation showed that the cell wall in vascular bundle sheath of Bk-x was thinner than that in normal plants. The leaf mechanical strength in Bk-x was 77.9% of that in normal plants growing at Xishuangbanna (BN), Yunnan province and that was 61.7% in Wuhan (WH), Hubei Province, China. The proportion of cellulose was 12.3% in Bk-x, which was significantly lower than that in normal plants (26.7%), while the soluble sugar content was 36.1% in Bk-x, which is significantly higher than that in normal plants (12.4%). Genetic analysis using two F₂ populations and one F_2:3 families demonstrated that the trait of brittle stalk is controlled by a single recessive gene.