Alternaria Brown Spot of Minneola in Greece; Evaluation of Citrus Species Susceptibility     

K. Elena 《European journal of plant pathology / European Foundation for Plant Pathology》2006,115(2):259-262

During the last three years, a new disease was observed in northwestern Greece on Minneola trees, hybrid of mandarin and grapefruit. On May small brown necrotic leaf spots surrounded by yellow halo areas of various sizes appeared and covered a major portion of the leaves with extension of necrosis into the veins. On young fruits small, slightly depressed black spots were the first symptoms, which later became 2–7 mm in diameter. Brown spots were observed on the leaves and fruits in several orchards in the same area, causing leaves and fruits to drop. In some orchards over 50% of the fruits were affected. From the fruit and leaf spots the typical small-spore species Alternaria alternata was isolated. Pathogenicity tests were performed by artificially inoculating fruits of Minneola, common mandarin and Clementine. The symptoms of the disease were reproduced only on fruits of Minneola hybrids by the specific strain of the fungus Alternaria alternata pv. citri. Different citrus susceptibility tests indicated that mandarins Minneola, Nova and Page were very susceptible to tested isolates while Clementine SRA and Poros Clementine were not. All lemons and lime Seedless were not susceptible. Grapefruit New Hall was not susceptible, while the Star Ruby was. Orange Lane Late, Navel Late, Oval Poros, Olinda, Navel Athos were not susceptible and only Moro showed reaction being slightly susceptible only to one isolate.  相似文献   

Phytophthora boehmeriae boll rot: a new threat to cotton cultivation in the mediterranean region     

K. Elena  E. J. Paplomatas 《Phytoparasitica》1998,26(1):20-26

A boll rot of cotton (Gossypium hirsutum L.) was observed for the first time in Greece in August 1993 in Larissa and Volos counties, and in August and September 1995 in Trikala and Phthiotis counties. Fungi of the genusPhytophthora were isolated from diseased plants. Morphological characteristics of the pathogen were recorded on mounts made directly from the infected tissues or after growth of the isolated fungus on corn meal agar or sterile distilled water. Colony morphology, growth rates, features of asexual and sexual structures and maximum growth temperatures were examined. APhytophthora species new to Europe,Phytophthora boehmeriae Sawada, attacking cotton bolls, was identified. The pathogenicity of the isolates was confirmed by artificial inoculations of detached cotton bolls. Analysis of α-esterase isozymes revealed unique banding patterns for isolates ofP. boehmeriae compared with those ofP. cactorum andP. parasitica, which arePhytophthora species with similar morphology.  相似文献   

Use of random amplified polymorphic DNA (RAPD) to identify races 1, 2, 4 and 8 of Fusarium oxysporum f. sp. dianthi in Italy     

Quirico Migheli  Elena Briatore  Angelo Garibaldi 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(1):49-57

The RAPD fingerprinting procedure was used in combination with pathogenicity assays on differential cultivars to characterize a representative collection of 72 Fusarium spp. isolates of different geographic origin collected from diseased carnation. In F. oxysporum f. sp. dianthi, isolates were grouped according to the physiologic race: group 1 included isolates of race 4; group 2 was formed by isolates of race 2 and single representatives of races 5 and 6; group 3 included isolates of races 1 and 8. No correlation was found between RAPD data and geographic origin of the isolates tested: representatives of race 2 isolated in Italy, Israel and Japan had the same amplification profile. Three isolates which showed a low level of pathogenicity on all carnation cultivars tested shared an identical amplification pattern and are probably saprophytic F. oxysporum. Finally, two F. redolens isolates from Japan and seven non-pathogenic isolates of F. proliferatum collected from diseased carnation in Italy, Israel and The Netherlands were clearly distinguishable according to their RAPD fingerprint. The results are discussed in relation to previous studies on the genetic diversity of F. oxysporum f. sp. dianthi and to the development of forma specialis- and pathotype-specific diagnostic tools.  相似文献   

Effect of single Quercus ilex trees upon spatial and seasonal changes in soil water content in dehesas of central western Spain     

Elena Cubera  Gerardo Moreno 《Annals of Forest Science》2007,64(3):355-364

The spatial and temporal evolution of soil water content (θ) in Quercus ilex dehesas has been investigated to determine how trees modify the soil water dynamics and the nature of tree-grass interactions in terms of soil water use in these ecosystems. Soil physical parameters and θ were measured at different distances from the tree trunk (2–30 m) in the upper 300 cm of soil. θ was measured monthly by TDR during 2002–2005. Tree water potential was determined during the summers of 2004 and 2005. At deeper soil layers, mean θ values were higher beyond than beneath tree canopy during dry periods. θ depletion beyond tree canopy continued even in summer, when herbaceous plants dried up, suggesting that trees uptake water from the whole inter-tree space. Results have shown a high dependence of trees on deep water reserves throughout late spring and summer, which helps to avoid competition for water with herbaceous vegetation.  相似文献   

Combined effect of wood moisture content,drill bit rotational speed and feed rate on drilling resistance measurements in Norway spruce (Picea abies (L.) Karst.)     

Evgenii Sharapov  Christian Brischke  Holger Militz  Elena Smirnova 《Wood material science & engineering》2020,15(4):198-204

ABSTRACT

An IML-RESI PD 400 drilling tool and a standard spade drill bit (IML System GmbH, Wiesloch, Germany) were used to study the combined effect of wood moisture content (MC), drill bit rotational speed and feed rate on drilling resistance (DR) and feeding force (FF). Tests were made with Norway spruce (Picea abies (L.) Karst.) conditioned in a normal climate (20°C/65% RH), at 20°C/95% RH, vacuum-pressure impregnated in water, and oven-dried. Rotational speeds and feed rates had an impact on feed rate per cutting edge for the major cutting edge of the drill bit which was used for correlation with DR and FF for various MC. Impact of MC on DR and FF depended on rotational speeds and feed rates of the drill bit. For feed rates per cutting edge less than 0.09?mm, DR was higher for water saturated (WS) specimens. Negligible differences between DR for various MC were found for feed rates per cutting edge between 0.09 and 0.15?mm. DR was higher at low MC for feed rates per cutting edge which were higher than 0.15?mm. FF extremely increased in conditioned (20°C/95% RH) and WS specimens at feed rates per cutting edge less than 0.1?mm.  相似文献   

What is your diagnosis? Pleural effusion in a dog with a gunshot wound          下载免费PDF全文

Francesca Bartolini  Martine Didier  Biagio Iudica  Elena Torti  Walter Bertazzolo 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2015,44(2):333-334

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Alopecia areata universalis in a dog          下载免费PDF全文

Pedro J. Ginel  Beatriz Blanco  María Pérez‐Aranda  Rafael Zafra  Elena Mozos 《Veterinary dermatology》2015,26(5):379-e87

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Covariation between plant biodiversity and soil systems in a European beech forest and a black pine plantation:the case of Mount Faito,(Campania,Southern Italy)     

Tiziana Danise  Michele Innangi  Elena Curcio  Antonietta Fioretto 《林业研究》2022,33(1):239-252

Both climate and land-use changes,including the introduction and spread of allochthonous species,are forecast to affect forest ecosystems.Accordingly,forests will be affected in terms of species composition as well as their soil chemical and biological characteristics.The possible changes in both tree cover and soil system might impact the amount of carbon that is stored in living plants and dead biomass and within the soil itself.Additionally,such altera-tions can have a strong impact on the detrital food web that is linked to litter decomposition.Although there are studies on the influence of plant diversity on soil physical and chemi-cal characteristics,the effects on soil biological activity and carbon storage processes remain largely unknown.The aim of this study was to investigate and compare chemical and biological variables in covariation with plant communities in an autochthonous beech forest (Fagus sylvatica L.) and a black pine plantation (Pinus nigra J.F.Arnold subsp.nigra).Our results confirmed that the two communities were con-siderably different,with the old-growth beech community having a lower number of plant species and the pine com-munity was in development as a consequence of anthropo-genic activities.These aspects of the two communities were also reflected in the soil,with the beech soil having higher nitrogen levels and a more specialized microbial community compared to the pine soil,with most extracellular enzymes(such as peroxidase and chitinase) showing lower activity in the pine soil.  相似文献   

Dietary fiber in brewed coffee     

Díaz-Rubio ME  Saura-Calixto F 《Journal of agricultural and food chemistry》2007,55(5):1999-2003

Coffee beans are rich in nondigestible polysaccharides (dietary fiber), which may partially pass into brewed coffee; however, to the authors' knowledge, there is not enough literature on dietary fiber in brewed coffee. A specific method to determine dietary fiber in beverages (enzymatic treatment plus dialysis) was applied to the coffees brewed by the most common methods (espresso, filter, soluble); results showed that brewed coffee contained a significantly higher amount of soluble dietary fiber (0.47-0.75 g/100 mL of coffee) than other common beverages. Coffee dietary fiber contains a large amount of associated antioxidant phenolics (8.7-10.5 mg/100 mL of brewed coffee).  相似文献   

Beta-carotene isomer composition of sub- and supercritical carbon dioxide extracts. Antioxidant activity measurement     

Jaime L  Mendiola JA  Ibáñez E  Martin-Alvarez PJ  Cifuentes A  Reglero G  Señoráns FJ 《Journal of agricultural and food chemistry》2007,55(26):10585-10590

In the present work sub- and supercritical extraction conditions using carbon dioxide were studied in order to obtain extracts with different compositions from the green microalgae Dunaliella salina. Different compositions of beta-carotene isomers were identified in the extracts by using HPLC-DAD. Also, antioxidant activity of the extracts was measured using a TEAC assay. An experimental design was applied considering two factors, extraction pressure and temperature, in a wide range of values, trying to maximize the extraction yield. Higher yields were obtained at high pressures and low temperatures, that is, at higher CO2 densities. Attempts were made to correlate the antioxidant activity of the extracts with their chemical composition by means of principal component analysis. A certain relationship was found between their antioxidant activity and the isomeric composition of beta-carotenes. As a result, an original equation is proposed to predict the antioxidant activity of extracts from D. salina in terms of the ratio 9-cis-beta-carotene/all-trans-beta-carotene, the concentration of alpha-carotene, and, especially, the concentration of 9-cis-beta-carotene.  相似文献