芽孢杆菌B11拮抗蛋白性质及其对西瓜枯萎病菌的作用机理

芽孢杆菌(Bacillus sp.)B11分离自土壤,其拮抗蛋白粗提液在温度60、80℃各处理30 min后仍能保持抗菌活性,对紫外线、蛋白酶K、RNase处理稳定,对胃蛋白酶、胰蛋白酶、氯仿部分敏感,作用活性pH(pH4～10)范围较宽.B11拮抗蛋白对西瓜枯萎病菌具有较强的拮抗作用,其抑菌机制主要使病菌菌丝畸形,细胞质浓缩,孢子不萌发或萌发异常.     

枯草芽孢杆菌G8抗菌蛋白的理化性质和抑菌作用

分离得到一株对黄瓜菌核病菌Sclerotinia sclerotiorum(Lib.)de Bary有拮抗作用的枯草芽孢杆菌G8,其无菌发酵液经硫酸铵沉淀得广谱抗菌粗蛋白。为明确枯草芽孢杆菌G8的理化性质,研究了温度、pH变化、UV照射、有机溶剂、蛋白酶和保存时间对抗菌蛋白稳定性的影响。结果表明:此粗蛋白耐酸,在pH值1~10范围内均有抑菌活性,将其pH值调为1.0作用16h后保持原有活性的69.2%;对温度有较高的稳定性,抗菌蛋白经100℃处理60min保持原有活性的80.8%;对蛋白酶K和有机溶剂不敏感;抗菌粗蛋白抑菌活性持久,在常温下120天保持原有活性的71.54%。初步研究了抗菌粗蛋白对黄瓜菌核病菌的抑制作用。结果显示,病菌菌丝消融、原生质渗漏、菌丝细胞泡囊化,并抑制病菌菌核萌发。     

短短芽孢杆菌A57菌株对棉花主要病原真菌的拮抗作用及其最佳液体发酵条件

研究了分离自棉花根际土壤的短短芽孢杆菌A57菌株对棉花立枯病菌、枯萎病菌和黄萎病菌的拮抗作用,在PDA平板上对峙培养,平均抑制率分别是33.5%、39.5%、29.5%。通过显微镜观察,发现拮抗细菌的主要拮抗机理是通过产生拮抗物质能够造成病原真菌菌丝体断裂、扭曲、畸形,抑制分生孢子的萌发,造成孢子畸形。以枯萎病菌为指示菌,研究了该菌株表现最佳拮抗活性时的菌液发酵条件,结果表明,A57适宜培养基为LB培养基,pH8,好气条件下抑菌活性最好。用硫酸铵沉淀法提取A57菌株的粗提蛋白,对供试的病原菌仍具有较高的拮抗活性,70%浓度时其拮抗活性最大,A57粗提蛋白对枯萎病原菌的最大抑制率为23.7%,同时该菌经硫酸铵沉淀后获得的粗体蛋白的上清液对病原指示菌仍具有一定的拮抗活性,说明A57拮抗细菌起拮抗作用的不仅有大分子蛋白类物质还有小分子拮抗物质。     

香蕉枯萎病拮抗菌的筛选及其作用机制研究

通过分离和筛选,从香蕉园或者其他果园的土壤中分离获得13株对香蕉枯萎病菌(Fusarium oxysporum f.sp.cubense)具有抑制作用的拮抗菌,并对部分拮抗菌抑制病菌菌丝生长和孢子萌发进行了试验。结果表明,拮抗菌株d4、d5、B3和p发酵液对香蕉枯萎病菌生长具有显著的抑制作用,在平板上产生的抑菌圈直径为21.75～34.75 mm,抑菌效果具有持续稳定性,对孢子萌发的抑制率为90.49%～97.18%;拮抗菌对病菌的作用表现为对菌丝的消融、菌丝细胞的泡囊化、抑制病菌分生孢子的萌发、孢子芽管的扭曲。     

葡萄灰霉病优势拮抗细菌的筛选与鉴定

以葡萄灰霉病病菌为供试菌,采用平板对峙法,研究了葡萄果穗附生细菌对葡萄灰霉病的拮抗效果。同时,进行生理生化、16S r DNA序列鉴定与同源性分析。结果表明,在分离得到的13株附生细菌中,其中11株对葡萄灰霉病有不同程度的拮抗作用,且拮抗菌的保护作用优于治疗作用。其中,B5和B12对葡萄灰霉病病菌孢子的抑菌率均为100%,对葡萄灰霉病病菌菌丝的抑菌率分别为14.49%和15.17%,显著高于其他拮抗菌(P0.05)。B5、B12菌株具有良好的拮抗和离体抑制效果,拮抗菌鉴定与同源性分析结果表明,B5属于芽孢杆菌属,B12属于枯草芽孢杆菌。     

马铃薯干腐病菌拮抗放线菌JY-22的抑菌作用及菌株鉴定

为了进一步明确拮抗放线菌JY-22对马铃薯干腐病的生防潜力,采用生长速率法和孢子萌发法测定了JY-22无菌发酵液(JY-22SFB)对马铃薯干腐病菌的抑菌作用及抑菌活性稳定性。JY-22SFB原液对马铃薯干腐病菌菌丝生长和孢子萌发均有很强的抑制作用,抑制率分别为74.5%和100%,其中对孢子萌发的抑制效果与浓度为30 mg/mL的化学药剂50%多菌灵相当。JY-22SFB处理后马铃薯干腐病菌菌丝生长畸形、易断裂。JY-22SFB对热处理和紫外线照射处理具有很好的稳定性,水浴80℃处理3 h和紫外线照射30 min对其抑菌活性没有影响。JY-22SFB浸泡处理可明显降低马铃薯干腐病菌的致病性。通过形态和分子鉴定,确定该菌属链霉菌属吸水链霉菌Streptomy-ces hygroscopicus。研究表明菌株JY-22在马铃薯干腐病生物防治中具有潜在的利用价值。     

短小芽胞杆菌AR03对烟草炭疽病的抑制作用

为测定短小芽胞杆菌AR03菌株对烟草炭疽病菌的室内拮抗活性和盆栽防治效果,采用平板拮抗法初步筛选菌株拮抗活性,采用抑制菌丝生长法及抑制孢子萌发法筛选该菌株菌悬液的抑菌浓度,采用喷雾法进行防治效果测定。AR03菌株对烟草炭疽病菌的拮抗活性很强,能显著抑制菌丝生长、孢子萌发和病害发生,浓度为1×107 cfu/mL的AR03发酵液能有效抑制菌丝的生长和孢子萌发,AR03菌悬液(1×108 cfu/mL)对炭疽病的盆栽防治效果为83.03%,与对照药剂25%三唑酮可湿性粉剂的防治效果相当。AR03菌株是一株优良的广谱高效生防菌株。     

枯草杆菌B034拮抗物质及其内源质粒的研究

 枯草杆菌(Bacillus subtilis) B034是从水稻叶面分离的植物病原细菌拮抗菌,对水稻白叶枯病菌,水稻细条病菌有较强的抑制作用。(NH₄)₂SO₄饱和沉淀粗提液经Sephadex G-100柱层析所得的3个洗脱吸收峰中有两峰具较强的抑菌活性。此拮抗物抗热,对胰蛋白酶敏感,对蛋白酶K、E部分敏感。B034菌株内含有一稳定的大小约8kb的内源质粒。质粒消除后,其拮抗活性也随之消失。用穿梭质粒pMK4的XL1-Blue中对其EcoR Ⅰ酶切4片段分别进行了克隆,并转化到无拮抗活性的Bacillus DB104中,片段Ⅱ+Ⅲ显示了部分的拮抗活性。     

稻曲病菌拮抗菌的筛选及拮抗活性测定

从对稻曲病菌具有拮抗能力的18株芽孢杆菌中选出拮抗作用较强的2个菌株A1、H-51,分别对稻曲病菌进行抑菌率、致畸性、孢子萌发影响以及对水稻促生性试验。结果表明,拮抗菌2个菌株的发酵液对稻曲病菌最大抑制率分别为67.66％和62.87％,对病菌分生孢子的萌发抑制率分别为77.37％和59.74％,但对水稻促生作用不明显。     

辣椒疫病生防菌的筛选及其抑菌机制初探

 观测了枯草芽孢杆菌BS、GF1和荧光假单胞菌LX1、BCA1 4株生防菌对7株来源不同的辣椒疫病病菌的拮抗作用和防治效果。结果表明:BS对辣椒疫病病菌菌丝的拮抗作用显著高于其它3株生防菌,抑制率达到33.2%~59.4%;温室防病试验中,BS喷雾处理和BCA1灌根处理对辣椒疫病具有明显的防治效果,防效分别达到56.83%和57.81%。BS抗菌粗提物对病菌菌丝生长具有明显的抑制作用,抑菌作用与抗菌粗提物稀释倍数呈负相关,稀释10倍时抑制率达到100%。BS抗菌粗提物处理使辣椒疫病病菌菌丝分枝增多,分枝间距明显缩短,分枝顶端原生质消解;同时可以显著抑制辣椒疫病病菌游动孢子的萌发速度和萌发率。对绿色荧光蛋白标记的BS菌株(gfp-BS)在辣椒幼苗各部位定殖情况的检测表明:该菌可以通过种子细菌化成功定殖于辣椒植株体内,出苗60 d后仍能检测到荧光标记的菌落,其定殖量维持在10³ cfu/g以上。     

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.     

Hymenopteran Parasitoids on Fruit-infesting Tephritidae (Diptera) in Latin America and the Southern United States: Diversity, Distribution, Taxonomic Status and their use in Fruit Fly Biological Control

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.     

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.     

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.     

Brief Guide for Authors

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     

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.     

The parasitoid complex ofLiriomyza cicerina on chickpea (Cicer arietinum)

Liriomyza cicerina (Diptera: Agromyzidae) is an important pest on chickpea in Turkey. The objective of this study was to determine the parasitoids and rates of parasitism ofL. cicerina on chickpea (Cicer arietinum L.) during the 2005 and 2006 seasons in ?anl?urfa province, Turkey. Leaves with mines were sampled weekly and kept in the laboratory to observe and count emerging leafminer and parasitoid adults. Eight parasitoid species were collected: the braconidsOpius monilicornis Fischer andOpius tersus Foerster and the eulophidsDiaulinopsis arenaria (Erdös) andNeochrysocharis formosa (Westwood), which occurred in both the winter and summer seasons;Diglyphus crassinervis Erdös,Neochrysocharis ambitiosa Hansson,Neochrysocharis sericea (Erdös) andPediobius metallicus (Nees), which occurred only in the summer growing areas.Diaulinopsis arenaria was the predominant parasitoid with 4–7.7% parasitism rate whileN. ambitiosa andO. monilicornis were the second and third most predominant species. The results of these trials show that sinceDia. arenaria occurred throughout every season, it could potentially be used for control of the leafminerL. cicerina.     

Plant–herbivore asynchrony necessitates augmentative releases of the exotic beetle,Zygogramma bicolorata,to enhance the biological control of P arthenium hysterophorus

Systematic information on the quantitative impact of Z ygogramma bicolorata on the biology of P arthenium hysterophorus is crucial as the seeds of this weed continue to germinate from the accumulated soil seed bank throughout the year in the form of different germinating flushes, while the activity of the beetle ceases during winter as it enters diapause. Therefore, plant–herbivore interactions need to be explored to develop predictions of the overall impact of the introduced beetle on the weed. The findings revealed that defoliation by Z . bicolorata had a significant impact on the plant height, density and flower production in flushes F ₃, F ₄ and F ₅, but not in F ₁ and F ₂ that exhibited longer periodicity, profuse branching, a longer flowering period and maximum flower production and contributed mostly to the existing seed soil bank. Therefore, total depletion of the existing soil seed bank was not possible. Consequently, the effect of augmentative field releases of laboratory‐reared beetles was explored on F ₁ and F ₂ in February for three consecutive years (2011–2013). Before initiating the trial, random soil samples were taken from the plots that were assigned to the paired treatments (i.e. with the beetle and without the beetle [insecticide‐treated]) and it was found that the seed bank in those samples did not differ. The single release of Z . bicolorata adults at five per plant at the six‐leaf stage significantly reduced the soil seed bank, compared to without the biocontrol agent, irrespective of the flushes at the end of the season.     

The use of Solacol® (validamycin) as a growth retardant in the isolation of soil fungi

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.