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1.
短期玉米秸秆还田对土壤细菌多样性的影响   总被引:1,自引:0,他引:1  
为揭示秸秆还田土壤细菌群落结构及其差异.在春玉米吐丝期,利用高通量测序技术,结合相关生物信息学分析,研究常规秸秆不还田(CK)、秸秆深翻还田(SF)和秸秆旋耕还田(XG)3个处理下,0-10cm、10-20cm、20-30cm 3个土层细菌群落丰富度、多样性和群落结构变化.秸秆还田对土壤细菌多样性影响较大,细菌菌群Alpha多样性及样品属水平群落组成丰度分析可知,XG及SF 10-30cm土层细菌多样性均比CK的高.CK中纤维素分解菌为鞘氨醇单胞菌属,而XG和SF中纤维素分解菌多样化,其中节杆菌属、湖沉积杆菌属、噬几丁质菌和乳杆菌属相对丰度较高.SF表层土壤固氮、解磷、解钾等功能细菌多样性均比XG的高.秸秆深翻还田提高土壤纤维素降解菌、固氮、解磷、解钾功能细菌多样性.  相似文献   

2.
秸秆连续还田对苏打盐碱水稻土养分及真菌群落的影响   总被引:3,自引:0,他引:3  
为探明水稻秸秆长期还田对苏打盐碱土养分状况以及土壤真菌群落结构的影响,采用盆栽试验,设置0(CK)、3.0(RS1)、7.5(RS2)、12.0(RS3)、16.5(RS4) t·hm~(-2) 5个梯度秸秆还田量,于连续还田5 a后测定土壤的pH值、有机质、全氮、全磷、全钾、速效养分含量以及真菌的相对丰度、Alpha多样性和群落结构变化。结果表明:秸秆还田显著降低了土壤全氮含量,降幅为20.37%~31.48%;RS1和RS3处理碱解氮含量较CK分别降低11.77%和9.61%;秸秆还田显著提高了土壤的pH值,增幅为9.39%~12.65%;RS4处理的有机质含量较CK增加了11.03%。随还田量的增加,全磷、有效磷和速效钾含量呈显著增加的趋势,均在RS4处理达到了最大值,较CK分别增加15.00%、49.34%、103.81%。总体上秸秆还田对苏打盐碱土起到了改良效果。Illumina MiSeq测序结果表明,还田量3.0 t·hm~(-2)时,Aphelidiomycota、轮虫门以及黄藻门相对丰度与CK分别相差20.40%、1.47%、0.08%;还田量16.5 t·hm~(-2)时,子囊菌门、担子菌门、裂壳菌属、柄孢壳属、腐质霉属以及被孢霉属与CK分别相差52.45%、1.40%、30.70%、16.84%、0.53%、0.44%,表明秸秆还田能够显著提高部分菌门和菌属的相对丰度。秸秆还田显著降低了土壤真菌Alpha多样性,ACE指数、Chao1指数、香浓指数降幅分别为10.86%~25.32%、7.81%~26.32%、0.25%~31.34%。秸秆还田处理改变了真菌的群落结构,其中RS3和RS4处理对其影响更为显著。进一步利用RDA和Mantel test分析表明,全钾(p0.05)、全磷(p0.05)、有效磷(p0.01)、速效钾(p0.01)以及有机质含量(p0.01)对真菌群落结构的影响显著。综合分析表明,秸秆还田能够调节土壤的理化性质,从而影响真菌的群落结构。  相似文献   

3.
手掌参内生真菌及根际土壤真菌的群落组成   总被引:1,自引:0,他引:1  
为筛选促生菌,采用高通量测序技术对手掌参茎、叶、果荚和根4种组织内生真菌及根际土壤真菌的群落组成进行分析。结果表明:从手掌参所有组织样品及根际土壤中共获得4 192个操作分类单元(operational taxonomic unit,OTU),其中茎中OTU数量最多,为1 096个,其次为根际土壤和叶中,分别为1 048个和983个,根中最少,为397个。所有样品中OTU注释后隶属于4门15纲,优势菌群为子囊菌门,相对丰度为47.25%~81.58%。属水平上主要菌群为枝孢霉属Cladosporium、粉褶蕈属Entoloma、背芽突霉属Cadophora和赤霉菌属Gibberella,分别为果荚、土壤、根、叶和茎中优势菌群。多样性指数表明茎中真菌群落的丰富度及多样性最高,而根部最低,不同样品之间真菌群落的多样性和丰富度差异显著。热图分析和主坐标分析均表明茎、叶和果荚中内生真菌的群落组成较相似,但与根部内生真菌和土壤中真菌的群落组成存在一定差异。  相似文献   

4.
为绿色防控草地贪夜蛾Spodoptera frugiperda,基于16S rDNA和ITS高通量测序分析,对分别取食玉米、小麦以及田间常见杂草婆婆纳Veronica polita的草地贪夜蛾肠道细菌和真菌进行物种注释、多样性分析、物种组成分析及功能预测。结果显示,细菌注释共获得20门30纲72目106科164属214种,真菌注释共获得9门23纲46目90科154属237种。厚壁菌门、放线菌门和变形菌门为取食玉米、小麦和婆婆纳的草地贪夜蛾肠道优势细菌门,子囊菌门和担子菌门为取食玉米、小麦和婆婆纳的草地贪夜蛾肠道优势真菌门。肠球菌属Enterococcus为取食玉米、小麦和婆婆纳的草地贪夜蛾肠道细菌共同的优势属,相对丰度分别为70.86%、25.42%和72.02%;丝孢酵母属Tricho-sporon 和帚枝霉属 Sarocladium 为取食玉米的草地贪夜蛾肠道真菌的优势属,相对丰度分别为57.28%和17.38%,酵母菌目未分类属、小囊菌属Microascus和丝孢酵母属Trichosporon为取食小麦的草地贪夜蛾肠道真菌优势属,相对丰度分别为29.31%、27.01%和15.45%,双足囊菌科未分类属为取食婆婆纳的草地贪夜蛾肠道真菌优势属,相对丰度为61.79%。取食小麦的草地贪夜蛾肠道细菌群落的多样性最高,取食婆婆纳的草地贪夜蛾肠道真菌群落的多样性最高,取食婆婆纳的草地贪夜蛾肠道细菌和真菌群落的丰富度最高。取食玉米、小麦和婆婆纳的草地贪夜蛾肠道细菌群落功能主要与代谢通路相关,取食玉米、小麦和婆婆纳的草地贪夜蛾肠道真菌群落功能主要与基础代谢或生理功能相关。  相似文献   

5.
以不同种植年限特殊药材根际土壤为材料,采用IlluminaNovaSeq高通量测序法和常规分析方法,分析了种植年限(0 a, 1 a, 4 a, 24 a)对根际土壤化学性质及微生物群落多样性的影响。结果表明:连续种植24 a后,土壤电导率、硝态氮含量显著高于其他种植年限。特殊药材连作对土壤细菌α-多样性指数均无显著影响,但土壤细菌丰富度和多样性减少;连续种植24 a真菌α-多样性指数中ACE指数、Chao1指数显著高于种植1 a,真菌丰富度和多样性增加。细菌群落Proteobacteria(变形菌门)、Acidobacteria(酸杆菌门)、Actinobacteria(放线菌门)为优势菌门,Sphingomonas(鞘氨醇单胞菌属)、Xanthomonadaceae(黄单胞菌科)相对丰度随着种植年限增加呈明显上升趋势,未知菌属RB41、Lysobacter(溶杆菌属)相对丰度呈下降趋势。土壤真菌群落Mortierellomycota(被孢霉门)、Ascomycota(子囊菌门)、Basidiomycota(担子菌门)为优势菌门,Mortierella(被孢霉属)相对丰度随种植年限增...  相似文献   

6.
本文比较分析了桑树青枯病发病和健康植株根际土壤肥力以及微生物(细菌和真菌)群落结构特征差异,旨在挖掘和利用丰富微生物资源的有益功能,为构建桑树青枯病生物防治技术体系奠定基础。结果表明,桑树青枯病发病植株根际土壤中指示土壤肥力与健康状况的生物学性状指标β-葡糖苷酶和磷酸酶的活性显著降低,微生物生物量碳、磷显著下降;细菌门分类水平上,发病植株根际土壤中酸杆菌门、放线菌门和疣微菌门等优势细菌相对丰度降低,变形菌门、绿弯菌门、粘球菌门、厚壁菌门、拟杆菌门等优势细菌相对丰度增加;细菌属分类水平上,发病植株根际土壤富集了硝化螺菌属和放线菌属等特有细菌属,缺失了诸如链霉菌属等具有分泌抗生素功能的优势细菌属。真菌门分类水平上,发病植株根际土壤中子囊菌门和担子菌门真菌相对丰度增加,unclassified_k_Fungi和霉菌门真菌相对丰度降低;真菌属分类水平上,发病植株根际土壤富集了地霉菌属、腐质霉属和丝孢菌属等腐生真菌,缺失了被孢霉属、枝顶孢属和曲霉属等具有产抑菌化合物功能的优势真菌。研究表明,桑树青枯病与根际土壤β-葡糖苷酶、磷酸酶活性,微生物生物量碳、磷以及微生物群落结构都具有一定的相关性。链霉菌属细菌以及被孢霉属、枝顶孢属和曲霉属真菌有望作为生物防控青枯病的有效备选菌属。  相似文献   

7.
依托布设在黄土高原雨养农业区的长期田间定位试验,以玉米田为对照、不同种植年限紫花苜蓿地(L2003,L2005,L2012)土壤为研究对象,采用真菌ITS高通量测序技术探究不同种植年限苜蓿土壤真菌群落分布与演替特征,为黄土高原苜蓿人工草地的可持续利用提供微生物参数。结果表明:黄绵土共检测到真菌6门24纲73目156科313属,主要包括子囊菌门(Ascomycota)、接合菌门(Zygomycota)、担子菌门(Basidiomycota)。苜蓿土壤和农田土壤真菌群落结构差异显著,随苜蓿种植年限延长子囊菌门相对丰度先降低后升高,接合菌门和担子菌门相对丰度先升高后降低,表现为L2003子囊菌门相对丰度显著高于L2005处理12.42%(P0.05),接合菌门相对丰度显著低于L2005处理153.54%(P0.05)。农田土壤优势属为被孢霉属(Mortierella)、绿僵菌属(Metarhizium)和腐质霉属(Humicola),苜蓿土壤共有优势真菌属为刺孢属(Phaeomycocentrospora)、白僵菌属(Beauveria)和被孢霉属。农田土壤被孢霉属相对丰度显著高于苜蓿土壤62.38%~73.48%(P0.05),随着苜蓿种植年限的延长,土壤促生菌(白僵菌属和绿僵菌属)丰度下降,部分病原菌(镰刀菌属、赤霉菌属)丰度增加。主成分分析发现,丛赤壳属(Nectria)、土赤壳属(Ilyonectria)和镰刀菌属(Fusarium)与第一主成分(PC1)具有较高的相关性,Lectera菌属、支顶孢属(Acremonium)和赤霉菌属(Gibberella)与第二主成分具有较高相关性,与第一、第二主成分相关性较高的菌属均为植物病原菌。  相似文献   

8.
胡蓉  郑露  刘浩  黄俊斌 《植物保护学报》2020,47(6):1261-1269
为探究稻麦轮作模式下秸秆还田对水稻根际微生物多样性与水稻纹枯病发生的影响,本研究采用Illumina测序技术结合生物信息学比较分析了秸秆还田与不还田处理的水稻根际微生物群落多样性差异,并采用实时荧光定量PCR (real-time fluorescent quantitative PCR,RT-qPCR)对这2种稻田土壤中水稻纹枯病菌Rhizoctonia solani含量进行测定,并采用随机五点取样法调查稻田中水稻纹枯病发病率和病情指数。结果表明,秸秆还田后水稻根际细菌群落Chao1丰富度指数和Shannon多样性指数均有所增加,分别增加14.42%和4.39%,其中前者增幅显著;根际真菌群落Chao1丰富度指数降低29.60%,而Shannon多样性指数略有增加,增加5.96%;在门水平上,秸秆还田和不还田处理的水稻根际土壤优势细菌门均为变形菌门、放线菌门、绿弯菌门和酸杆菌门,优势真菌门均为子囊菌门、接合菌门和担子菌门;在属水平上,秸秆还田处理的硝化螺旋菌属和芽胞杆菌属相对丰度分别比不还田处理的显著增加96.11%和106.19%;在水稻孕穗期秸秆还田土壤中水稻纹枯病菌含量比不还田处理的显著增加120.20%;秸秆还田后水稻纹枯病发生加重,病情指数比不还田处理的增加18.10%~45.41%。  相似文献   

9.
分析新疆典型干旱区轮台国家果树资源圃不同品种苹果树叶片内生真菌的分布特征及差异,为病害防治、品种选育和筛选功能微生物菌株提供参考。利用ITS基因高通量测序技术对6个品种苹果树叶片内生真菌进行测序,并比较其群落组成和功能特性。研究表明,苹果树叶片蕴含着丰富多样的内生真菌资源,共检测到真菌序列566453条,鉴定到5个门、15个纲、30个目、42个科及43个属。不同品种间内生真菌群落多样性存在一定差异,野苹果叶片内生真菌的多样性指数和丰度指数均较高。在门水平上的优势真菌菌群为子囊菌门(85.22%~98.68%),不同品种间差异不大。在纲和属上不同品种间有一定的差异,子囊菌门中的锤舌菌纲和座囊菌纲为优势纲,相对丰度分别在17.48%~69.69%和28.21%~67.59%之间;可归类的优势真菌属包括小粉孢属(17.47%~69.68%)、链格孢属(13.36%~39.35%)、枝孢霉属(2.94%~8.80%)和隐球菌属(0.20%~2.36%)。不同品种苹果树叶片真菌共有属的OTU数有42个,占各样品相对丰度的99%以上,而独有属的丰度各品种均低于1%。由于长期适应干旱区环境,在属水平...  相似文献   

10.
 为探究施用烯酰吗啉后不同葡萄叶际微生物群落变化,以田间‘红地球’品种葡萄为研究对象,连续施用农药烯酰吗啉,采集不同组别样品,利用 Illumina Hiseq 高通量测序技术分析葡萄叶际真菌、细菌群落结构变化。基于可操作分类单元(operational taxonomic units, OTUs)的物种分类分析,共得到葡萄叶际微生物真菌群落共计6个门,23个纲,60个目,131个科,212个属,296个种;细菌群落共计42个门,91个纲,222个目,398个科,846个属,1 469个种。在云南农业大学砂壤土质、篱架式栽培的‘红地球’葡萄基地中发现:(1)葡萄叶际优势真菌有枝孢菌属(Cladosporium)、白粉菌属(Erysiphe)、unclassified -k_-Fungi属和Symmetrospora属;优势细菌有乳杆菌属(Lactobacillus)、双歧杆菌属(Bifidobacterium)、拟杆菌属(Bacteroides)、肠球菌属(Enterococcus)、毛螺菌属(unclassified-f-Lachnospiraceae)、norank-f-Muribaculaceae属、芽孢杆属(Bacillus)、Blautia属和肠杆菌属(Kosakonia)。(2)经烯酰吗啉处理后,在健康葡萄叶片中其叶际真菌群落丰富度略降低,多样性显著增加,叶际细菌群落丰富度增加,多样性增加,但零星发病叶片中,叶际真菌、细菌群落丰富度和多样性则显著降低。(3)在零星发病葡萄叶片中,相对健康叶片,葡萄叶际真菌群落之间的差异被增大,而葡萄叶际细菌群落的差异被减小。(4)在健康及发病叶片中,相对丰度均上调的真菌为白粉菌属(Erysiphe)、球腔菌属(Mycosphaerella)、线黑粉酵母属(Filobasidium)、黑孢霉属(Nigrospora)、赤霉属(Gibberella)、被孢霉菌(Mortierella)和镰刀菌属(Fusarium),细菌为巨单胞菌属(Megamonas)、链球菌属(Streptococcus)、葡萄球菌属(Staphylococcus)和弯曲杆菌属(Campylobacter);相对丰度均下调的真菌为枝孢属(Cladosporium)、壳针孢属(Septoria)、链格孢属(Alternaria)和担孢酵母属(Erythrobasidium);细菌为短小杆菌属(Kosakonia)鞘脂单胞菌属(Sphingomonas);推断这些菌对烯酰吗啉较为敏感。(5)施用烯酰吗啉农药对葡萄叶际微生物的影响在健康叶片与零星发病叶片中有差异,且有新的优势菌属出现。  相似文献   

11.
Fifteen species of dermestid beetles were recorded at ‘Evolution Canyon’ (EC), Lower Nahal Oren, Mt. Carmel, Israel. They represent ~35% of known Israeli dermestid species. The following three species were recorded for the first time in Israel:Trogoderma svriaca Dalla Torre, 1911;Ctesias svriaca Ganglbauer, 1904; andAnthrenus (s.str.) jordaniens Pic, 1934. Adults of 13 species were collected on the more solar radiated, warmer and climatically more fluctuating south-facing slope (SFS); ten species were collected on the opposite, north-facing slope (NFS), which was cooler and climatically more stable. The abundance of adult dermestid beetles was 1.9 times higher on the SFS than on the NFS (86 and 47, respectively). Species richness and abundance distribution at EC (three collecting stations on each slope and one at the valley bottom) were significantly negatively correlated with the plant cover that consisted of trees and bushes (Spearmanr s ,P=0.007 and 0.039, respectively) and perennials (Spearmanr s ,P=0.039 and 0.077, respectively), indicating that non-woody plants were preferred by adult dermestid beetles.  相似文献   

12.
Molecular diagnostic techniques have been developed to differentiate the Ascochyta pathogens that infect cool season food and feed legumes, as well as to improve the sensitivity of detecting latent infection in plant tissues. A seed sampling technique was developed to detect a 1% level of infection by Ascochyta rabiei in commercial chickpea seed. The Ascochyta pathogens were shown to be genetically diverse in countries where the pathogen and host have coexisted for a long time. However, where the pathogen was recently introduced, such as A. rabiei to Australia, the level of diversity remained relatively low, even as the pathogen spread to all chickpea-growing areas. Pathogenic variability of A. rabiei and Ascochyta pinodes pathogens in chickpea and field pea respectively, appears to be quantitative, where measures of disease severity were based on aggressiveness (quantitative level of infection) rather than on true qualitative virulence. In contrast, qualitative differences in pathogenicity in lentil and faba bean genotypes indicated the existence of pathotypes of Ascochyta lentis and Ascochyta fabae. Therefore, reports of pathotype discrimination based on quantitative differences in pathogenicity in a set of specific genotypes is questionable for several of the ascochyta-legume pathosystems such as A. rabiei and A. pinodes. This is not surprising since host resistance to these pathogens has been reported to be mainly quantitative, making it difficult for the pathogen to overcome specific resistance genes and form pathotypes. For robust pathogenicity assessment, there needs to be consistency in selection of differential host genotypes, screening conditions and disease evaluation techniques for each of the Ascochyta sp. in legume-growing countries throughout the world. Nevertheless, knowledge of pathotype diversity and aggressiveness within populations is important in the selection of resistant genotypes.  相似文献   

13.
Recent data on the epidemiology of the common mycotoxigenic species of Fusarium, Alternaria, Aspergillus and Penicillium in infected or colonized plants, and in stored or processed plant products from the Mediterranean area are reviewed. Emphasis is placed on the toxigenicity of the causal fungal species and the natural occurrence of well known mycotoxins (aflatoxins, ochratoxins, fumonisins, trichothecenes, zearalenone, patulin, Alternaria-toxins and moniliformin), as well as some more recently described compounds (fusaproliferin, beauvericin) whose toxigenic potential is not yet well understood. Several Fusarium species reported from throughout the Mediterranean area are responsible of the formation of mycotoxins in infected plants and in plant products, including: Fusarium graminearum, F. culmorum, F. cerealis, F. avenaceum, F. sporotrichioides and F. poae, which produce deoxynivalenol, nivalenol, fusarenone, zearalenone, moniliformin, and T-2 toxin derivatives in wheat and other small grains affected by head blight or scab, and in maize affected by red ear rot. Moreover, strains of F. verticillioides, F. proliferatum, and F. subglutinans, that form fumonisins, beauvericin, fusaproliferin, and moniliformin, are commonly associated with maize affected by ear rot. Fumonisins, were also associated with Fusarium crown and root rot of asparagus and Fusarium endosepsis of figs, caused primarily by F. proliferatum. Toxigenic A. alternata strains and associated tenuazonic acid and alternariols were commonly found in black mould of tomato, black rot of olive and citrus, black point of small cereals, and black mould of several vegetables. Toxigenic strains of A. carbonarius and ochratoxin A were often found associated with black rot of grapes, whereas toxigenic strains of A. flavus and/or P. verrucosum, forming aflatoxins and ochratoxin A, respectively, were found in moulded plant products from small cereals, peanuts, figs, pea, oilseed rape, sunflower seeds, sesame seeds, pistachios, and almonds. Finally, toxigenic strains of P. expansum and patulin were frequently found in apple, pear and other fresh fruits affected by blue mould rot, as well as in derived juices and jams.  相似文献   

14.
We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.  相似文献   

15.
The genera ofMicrogaster Latreille 1804 andHygroplitis Thomson 1895 from China are presented systematically in this paper. Thirty-two species ofMicrogaster and three species ofHygroplitis are known in China. Diagnosis, character variation, distribution and host of each species among the two genera are presented, including its host and distribution. Keys to the species ofMicrogaster andHygroplitis are given. http://www.phytoparasitica.org posting Dec. 19, 2006.  相似文献   

16.
Plant Viruses Transmitted by Whiteflies   总被引:18,自引:0,他引:18  
One-hundred and fourteen virus species are transmitted by whiteflies (family Aleyrodidae). Bemisia tabaci transmits 111 of these species while Trialeurodes vaporariorum and T. abutilonia transmit three species each. B. tabaci and T. vaporariorum are present in the European–Mediterranean region, though the former is restricted in its distribution. Of the whitefly-transmitted virus species, 90% belong to the Begomovirus genus, 6% to the Crinivirus genus and the remaining 4% are in the Closterovirus, Ipomovirus or Carlavirus genera. Other named, whitefly-transmitted viruses that have not yet been ranked as species are also documented. The names, abbreviations and synonyms of the whitefly-transmitted viruses are presented in tabulated form together with details of their whitefly vectors, natural hosts and distribution. Entries are also annotated with references. Whitefly-transmitted viruses affecting plants in the European–Mediterranean region have been highlighted in the text.  相似文献   

17.
《干旱区科学》2014,(6):782-782
正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad  相似文献   

18.
Solacol®, a formulation of the antibiotic validamycin, at 0.33% in 2% malt extract agar, reduced the spread of fungi on dilution plates drastically and allowed twice as much incubation time before subculturing; this resulted in an elevated number of species isolated. Using pure cultures of 62 common soil fungi, it was shown that all fast-growing species (exceptPythium ultimum) were efficiently inhibited but not completely suppressed. Inhibition was comparable to that by 0.5% oxgall, though, while this substance completely suppressed several species, Solacol very strongly inhibited onlyGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum andRhizoctonia solani. In a further experiment each separate constituent of Solacol was tested against 22 fungi at equivalent concentrations. Validamycin strongly inhibitedChaetomium globosum and two Basidiomycetes, though hardly more than the non-ionic detergent which mainly inhibited the other fungi. A few species were, however, more inhibited by Solacol than by the detergent alone. Solacol at 0.33% is a suitable aid in dilution plating of soil fungi, by increasing the number of colonies and species observed.Samenvatting Solacol®, een formulering van het antibioticum validamycine, remde de groei van schimmels in verdunningsplaten met een concentratie van 0.33% in 2% moutagar en maakte het mogelijk de periode tot afenten met een factor 2 te verlengen; daardoor was het aantal geïsoleerde soorten duidelijk toegenomen. Met reincultures van 62 algemene grondschimmelsoorten werd aangetoond, dat alle snelgroeiende soorten (met uitzondering vanPythium ultimum) voldoende geremd, maar niet volkomen onderdrukt werden. Het remmingspercentage was vergelijkbaar met dat van 0.5% ossegal, hoewel dit laatste sommige soorten volkomen onderdrukte; Solacol remde alleenGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum enRhizoctonia solani zeer sterk. In een volgend experiment werden de componenten van Solacol t.o.v. 22 fungi apart getoetst in concentraties equivalent aan 0.33% Solacol. Validamycine remde alleenChaetomium globosum en twee basidiomyceten behoorlijk, maar nauwelijks meer dan de niet-ionische uitvloeier, die in hoofdzaak de overige remeffecten veroorzaakte. Enkele soorten werden echter door het complete Solacol veel sterker geremd dan door de uitvloeier alleen. Solacol in een verdunning van 0,33% wordt aanbevolen bij verdunningsplaten voor het isoleren van grondschimmels ten einde het aantal kolonies en soorten te verhogen.  相似文献   

19.
Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.  相似文献   

20.
A collection of 38 PVY isolates from seed potato batches, originating from several Western European countries, was characterized by using current biological, serological and molecular tools differentiating PVY strains and groups. The correlation between the three kinds of tests was good but not absolute. No single serological or PCR method was able to discriminate among the five isolate groups found. Twenty-nine isolates belonged to the PVYN strain and six to the PVYO strain. No PVYC was found. Two other isolates reacted serologically like PVYO, but were unable to elicit a hypersensitive response from the Nytbr gene and probably represent the PVYZ group. At the molecular level, these two isolates showed a combination of both PVYO and PVYN and could be recombinants of these strains. Another isolate reacted serologically like PVYO, but induced vein necrosis in tobacco, like PVYN-Wilga. Some PVYN isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVYNTN group. The PVYNTN, PVYN-Wilga and PVYZ groups probably represent pathotypes within strains PVYN and PVYO, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.  相似文献   

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