来源于中药的稻瘟病菌拮抗解淀粉芽胞杆菌鉴定及其活性成分特性

为寻找新的水稻稻瘟病拮抗微生物资源,本研究从中药提取液中分离纯化到一株性能优良的拮抗细菌CWJ2。平板对峙试验显示该菌株对水稻稻瘟病菌丝生长抑制率为69.51%。根据菌落、菌株形态、16S rDNA和gyrB基因序列,鉴定该菌株为解淀粉芽胞杆菌Bacillus amyloliquefaciens。该菌株发酵滤液能明显抑制稻瘟病菌菌丝生长和孢子萌发,10%的发酵滤液能100%抑制菌丝生长;2%的发酵滤液能导致菌丝分支明显减少,菌丝变短、膨大或畸变。菌株CWJ2的发酵液在高温、蛋白酶K、紫外和酸碱处理下,抑菌活性无显著变化。试验结果表明,菌株CWJ2对稻瘟病菌拮抗效果好,且抗菌活性成分稳定,有望作为生防菌株开发防治稻瘟病制剂。     

番茄灰霉病菌拮抗放线菌的筛选、鉴定及其活性评价

从安徽省寿县农田土壤中分离筛选到1株对番茄灰霉病菌Botrytis cinerea有强拮抗作用的放线菌菌株HNU-1。根据菌体形态特征、培养特征、细胞壁组分、生理生化特性和16S rRNA基因序列分析,将该菌株鉴定为吸水链霉菌Streptomyces hygroscopicus。菌株HNU-1发酵滤液可抑制灰霉病菌菌丝生长和分生孢子萌发,且浓度越高,抑制能力越强;当发酵滤液稀释6.67倍时则完全抑制灰霉病菌菌丝生长和分生孢子萌发。盆栽试验结果表明,菌株HNU-1发酵滤液6.67倍稀释液对番茄灰霉病的预防与治疗效果分别为87.8%和77.9%,均显著高于50%多菌灵可湿性粉剂500倍稀释液。     

假单胞杆菌B301对稻瘟病菌的拮抗性

B301是一株分离自空气中的假单胞杆菌（Pseudomonas sp.)。室内测定表明,它能抑制稻瘟病菌的分生孢子萌发和菌丝生长。病菌分生孢子在B301发酵液的2倍稀释液中完全不能萌发,40倍稀释液中的萌发率为35.58%,比对照下降59.4%。B301发酵液稀释140倍时,对病菌菌丝生长的抑制率为52.1%,其抑制菌丝生长的最大稀释度为4480倍。B301发酵液中的抗菌物质具有较强的耐热性,在80℃下,60min仍保持原有活性,但当温度上升到100℃后则不稳定,10min内活性显著下降,80min后完全失活。田间防治试验表明,B301发酵液防治稻瘟病的效果为45％左右,与对照药剂20％三环唑可湿性粉剂500倍液防效相当。此外,B301还能有效抑制棉花炭疽病菌和玉米小斑病菌的生长。     

三株拮抗细菌对辣椒青枯病的防治试验

生防菌bio-1、bio-2和bio-P为稻瘟病生防菌,为了测试其对辣椒青枯病的防治作用,本实验利用其发酵原液及其100倍、200倍和300倍稀释液进行室内抑菌试验和盆栽防治试验。结果显示,生防菌bio-1、bio-2和bio-P发酵原液抑菌能力最强,抑菌圈直径分别为20.25㎜、30㎜和19.25㎜;生防菌bio-1的发酵原液和200倍稀释液对辣椒青枯病的预防效果达66.7%,100倍稀释液和300倍稀释液的预防效果分别为33.3%和50%;而生防菌bio-2的100倍稀释液的防治效果达100%,发酵原液的预防效果为66.7%,200倍稀释液和300倍稀释液的预防效果分别为16.7%和50%,这二株生防菌对辣椒青枯病均无治疗效果。     

拮抗性链霉菌对大丽轮枝菌微菌核形成与萌发的影响

为探索拮抗性链霉菌对棉花黄萎病病原大丽轮枝菌Verticillium dahliae Kleb.的抑菌机制,采用菌丝生长速率法、微菌核萌发法研究了6株拮抗链霉菌无菌发酵滤液对大丽轮枝菌生长、微菌核形成与萌发的影响。链霉菌无菌发酵滤液对大丽轮枝菌菌落生长、菌核形成和微菌核萌发有明显抑制作用。其中菌株B49的抑菌效果最好,5倍稀释发酵液培养14天时对菌落生长的抑菌率达69.7%;菌株B49、D184和Act12的5倍稀释发酵液对微菌核形成的抑制率达100%;将经B49、D184和Act12发酵液处理后丧失形成微菌核能力的大丽轮枝菌菌株转接至不含发酵液的PDA培养基,连续传代至第5代,其仍然不能恢复形成微菌核的能力;微菌核在含有菌株D184 5倍稀释发酵液的培养基上培养168 h时,萌发率仅为38.3%。     

假单胞杆菌B_(301)对稻瘟病菌的拮抗性

B_(301)是一株分离自空气中的假单胞杆菌(pseudomonas sp.)。室内测定表明,它能抑制稻瘟病菌的分生孢子萌发和菌丝生长。病菌分生孢子在B_(301)发酵液的2倍稀释液中完全不能萌发,40倍稀释液中的萌发率为35.58％,比对照下降59.4％。B_(301)发酵液稀释140倍时,对病菌菌丝生长的抑制率为52.1％,其抑制菌丝生长的最大稀释度为4480倍。B_(301)发酵液中的抗菌物质具有较强的耐热性,在80℃下,60min仍保持原有活性,但当温度上升到100℃后则不稳定,10min内活性显著下降,80min后完全失活。田间防治试验表明,B_(301)发酵液防治稻瘟病的效果为45％左右,与对照药剂20％三环唑可湿性粉剂500倍液防效相当。此外,B_(301)还能有效抑制棉花炭疽病菌和玉米小斑病菌的生长。     

黄瓜枯萎病菌拮抗菌的筛选、鉴定和防效测定

为获得对黄瓜枯萎病菌Fusarium oxysporum f. sp. cucumerinum(FOC)具有拮抗作用的生防菌株,采用稀释涂布平板和平板生长对峙法从健康黄瓜根际土壤中分离、筛选对FOC具有强拮抗能力的拮抗细菌,并从形态学观察、生理生化特性、全细胞脂肪酸分析及16S rRNA和gyr B基因序列相似性对拮抗能力最强的菌株进行鉴定,同时测定拮抗菌无菌过滤发酵液对FOC菌丝生长、孢子萌发的抑制作用,并评价其发酵液对盆栽和大田黄瓜枯萎病的防治效果。研究结果显示,从健康黄瓜根际土壤中分离获得23株对FOC具有拮抗作用的细菌,其中菌株FJ17-4对FOC抑菌作用最强,鉴定为贝莱斯芽胞杆菌Bacillus velezensis。FJ17-4抑制FOC引起菌丝畸形、扭曲、膨胀、皱缩、缠绕等异常现象。10%无菌过滤液对FOC菌丝生长和孢子萌发的抑制率分别为70.96%和85.40%。50倍发酵液、菌体悬浮液和无菌过滤液盆栽防治效果分别为70.20%、58.87%和47.80%,大田防治效果分别为69.53%、58.46%和36.12%。综上,FJ17-4能有效抑制FOC,对黄瓜枯萎病具有显...     

蓝莓枝枯病拮抗细菌HMQAU140045的鉴定和抑真菌活性

以蓝莓毛色二胞枝枯病菌假可可毛色二胞Lasiodiplodia pseudotheobromae为靶标菌,通过稀释平板法从山东青岛的蓝莓种植园根际土壤中分离出20株细菌,采用对峙平板法和菌丝生长速率法筛选得到一株对靶标菌具有明显抑制效果的拮抗菌株HMQAU140045,采用凹玻片法和菌丝生长速率法测定该菌株发酵滤液对靶标菌孢子萌发和菌丝生长的影响。结果表明,稀释50倍的发酵滤液的抑制率可达100%。离体枝条试验结果表明,发酵液不同组分对蓝莓毛色二胞枝枯病的防治效果均可达90%以上。菌丝生长速率法测定结果表明,该菌株抑真菌谱广,对包括4种蓝莓枝枯病菌在内的15种植物病原真菌具有良好的拮抗作用。通过形态观察、生理生化特性以及gyrB的序列分析,确定该菌株为解淀粉芽孢杆菌Bacillus amyloliquefaciens。试验结果表明,解淀粉芽孢杆菌菌株HMQAU140045具有较好的抑真菌活性。     

绛红褐链霉菌YSSPG3的发酵条件及其发酵滤液对杂交竹梢枯病的防治作用

绛红褐链霉菌YSSPG3是从四川碧峰峡撑×绿杂交竹健康植株根际分离到的一株对杂交竹梢枯病菌有抗菌活性的放线菌。为进一步明确该菌的生防潜力,采用正交设计进行发酵培养基优化,并通过分生孢子萌发试验、菌丝抑制试验、离体枝叶接种试验及田间防治试验,研究了优化发酵培养滤液对杂交竹梢枯病的防治效果。结果显示,最优培养基组成为葡萄糖5 g、甘油5 g、黄豆饼粉3 g、蛋白5 g、NaCl 2.5 g、CaCO32 g、蒸馏水1 000 mL。优化发酵培养滤液对病原菌分生孢子萌发及菌丝生长均有明显的抑制作用,可导致芽管、菌丝畸形。去菌发酵原液及其10倍稀释液处理离体枝叶能有效抑制病斑扩展,接种后4天的防治效果在70%以上。田间喷施去菌发酵原液及其5倍稀释液防治效果均达80%以上,极显著高于浓度为30 mg/mL的化学药剂50%多菌灵和70%甲基硫菌灵(P<0.01)。     

黄瓜褐斑病菌拮抗细菌的筛选及鉴定

从全国14个地区多种作物田采集土样56份,经室内分离、纯化及筛选,获得了对黄瓜褐斑病菌Corynespora cassiicola具有拮抗作用的16株细菌,其中拮抗作用最强的为菌株SDYT-79,其对黄瓜褐斑病菌的抑菌带宽度达37mm。室内盆栽试验结果显示,菌株SDYT-79对黄瓜褐斑病的防效达58.4%。孢子萌发试验表明,该菌株对黄瓜褐斑病菌孢子萌发有较强的抑制作用,其发酵无菌滤液及10倍稀释液对孢子萌发的抑制率均达100%。黄瓜褐斑病菌孢子在100倍、1000倍稀释无菌滤液中虽能萌发,但芽管形态异常。抑菌谱试验表明,该菌株对供试的11种植物病原真菌均有较好的抑菌作用,抑菌带在19.9～41.9mm之间。生理生化鉴定及16S rDNA序列测定结果表明该菌株为地衣芽孢杆菌Bacillus licheniformis。     

Dermestid beetles in ‘evolution Canyon’, lower Nahal Oren, Mt. Carmel, including new records for Israel

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.     

Epidemiology of Toxigenic Fungi and their Associated Mycotoxins for Some Mediterranean Crops

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.     

A survey of the genera of<Emphasis Type="Italic">Microgaster</Emphasis> latreille and<Emphasis Type="Italic">Hygroplitis</Emphasis> thomson (Hymenoptera: Braconidae: Microgastrinae) from China

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.     

Plant Viruses Transmitted by Whiteflies

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.     

Broad bean mottle virus in Morocco; curculionid vectors,and natural occurrence in food legumes other than faba bean (Vicia faba)

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.     

Characterization of potato potyvirus Y (PVY) isolates from seed potato batches. Situation of the NTN, Wilga and Z isolates

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 PVY^N strain and six to the PVY^O strain. No PVY^C was found. Two other isolates reacted serologically like PVY^O, but were unable to elicit a hypersensitive response from the Ny_tbr gene and probably represent the PVY^Z group. At the molecular level, these two isolates showed a combination of both PVY^O and PVY^N and could be recombinants of these strains. Another isolate reacted serologically like PVY^O, but induced vein necrosis in tobacco, like PVY^N-Wilga. Some PVY^N isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVY^NTN group. The PVY^NTN, PVY^N-Wilga and PVY^Z groups probably represent pathotypes within strains PVY^N and PVY^O, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.     

The autumn leafroller: Phenology,damage and parasitoids in a Dutch apple orchard

The phenology of the autumn leafroller,Syndemis musculana, a local pest of apple, was studied in order to forecast larval emergence. From 1983–1986, peak flight as determined with sexpheromone traps was always between 13–18 May. The duration of embryonic development was determined at various constant temperatures and used to estimate the periods of egg hatch in these four years. Each year, most eggs should have hatched in the second decade of June.Differences in attack rates between apple cultivars seem to be explained largely by the variation in picking time. Larvae are only half grown at the beginning of harvest (cv. James Grieve), and have gone into hibernation when the latest variety (cv. Golden Delicious) is picked. Moreover, the varieties Cox's Orange Pippin and Belle de Boskoop, picked about half time, are liable to receive additional damage by caterpillars brought with the picked fruits into storage.Various hymenopterous parasites were reared from caterpillars. As the only leafroller in the orchard which hibernates as mature larva,S. musculana may promote winter survival of some parasitoids, like the eulophidColpyclypeus florus.Samenvatting De fenologie van de herfstbladroller (Syndemis musculana Hübner), een incidentele plaag op appel, werd nader bepaald met het doel het uitkomen van de eieren te kunnen voorspellen. In 1983–1986 viel de piekvlucht, bepaald met behulp van feromoonvallen, steeds tussen 13 en 18 mei.De ontwikkelingsduur van de eieren bij verschillende constante temperaturen werd gebruikt om de periode van uitkomen te schatten. De meeste eieren zullen ieder jaar in de eerste helft van juni uitkomen.Geconstateerde verschillen in schade tussen appelrassen blijken goeddeels terug te voeren op verschillen in pluktijdstip. De rupsen van de herfstbladroller zijn pas half-was als de eerste appels eind augustus geplukt worden, terwijl tegen het einde van de oogst begin oktober de meeste al in winterslaap zijn. Met name tussentijdse rassen, als Cox's Orange Pippin and Schone van Boskoop, lopen extra schade op doordat grotere rupsen met de geplukte vruchten in de kist terecht komen.Uit de rupsen werden negen, al van andere boomgaardbladrollers bekende, sluipwespen gekweekt, Omdat deze bladrollersoort, als enige in de boomgaard, als volgroeide rups overwintert, lijkt zij bij uitstek geschikt als winterwaard.This study was carried out at the Experimental Orchard De Schuilenburg, Schuilenburg 3, 4041 BK Kesteren, the Netherlands, to which address correspondence should be addressed.     

Diagnostics,genetic diversity and pathogenic variation of ascochyta blight of cool season food and feed legumes

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.     

Characterization of Sclerotinia minor populations in Texas peanut fields

In the summer of 2004 an epidemic of sclerotinia blight of peanut, a disease caused by Sclerotinia minor, occurred in Texas in fields where the disease was never previously detected. The disease was observed on many plants within one of the fields (>3000 disease foci), although most foci were <1 m. It is hypothesized that these observations were inconsistent with the recent introduction of a monocyclic pathogen, even if disease developed under conducive environmental conditions. The pattern of disease is most suggestive of the presence of foliar (ascospore) infections, although air temperature was above the known limits for apothecia development if the pathogen had arrived in the field in 2004 peanut seed. To further examine this epidemic, 232 isolates were collected, across a variety of spatial scales spanning this field and other Texas peanut fields, and evaluated for aggressiveness, fungicide sensitivity and genotypic diversity. There was wide variation among isolates for the phenotypic characteristics measured, but there was no evidence that a genotypically unique, highly aggressive, and fungicide resistant isolate had been introduced or evolved. The predominant genotype, TX1, which contained 154 isolates, was found in every county and field population.     

Eyespot of Cereals Revisited: ITS phylogeny Reveals New Species Relationships

Four species so far classified in Pseudocercosporella or Ramulispora (hyphomycetes) are associated with eyespot disease symptoms of cereals. Two of these have been linked to teleomorphs that were described in Tapesia. Sequence data derived from the Internal Transcribed Spacer region (ITS1, 5.8S and ITS2) of the rDNA operon showed, however, that the eyespot fungi associated with Tapesia are not congeneric with Ramulispora sorghi, the type of Ramulispora. The genus name Tapesia is now rejected in favour of the conserved name Mollisia, which appears to comprise heterogeneous fungi. Tapesia yallundae is not closely related to the type of Mollisia, M. cinerea, but clusters separately, being more closely allied to species with Cadophora anamorphs. A new holomorph genus, Oculimacula, is therefore proposed for teleomorphs of the eyespot fungi, while the anamorphs are accommodated in Helgardia gen. nov.