Annulotrematoides bryconi sp. n. (Monogenea: Dactylogyridae) parasitic on Brycon cephalus (Osteichthyes: Characidae) from Brazil

Annulotrematoides bryconi sp. n. is described and illustrated from specimens collected from gills of characiform fish, Brycon cephalus (Günther, 1869), in pisciculture ponds from Pirassununga, S?o Paulo, Brazil. Diagnostic characters of the new species are the tegument of trunk showing annulations, except on the cephalic regiona, and copulatory complex comprising sclerotized male copulatory organ coiled in 1 1/2 rings. This is the first record of monogeneans parasitic on the gills of B. cephalus.     

Rapid Identification of Agrobacterium Species By Staircase Electrophoresis of Low Molecular Weight RNA Profiles

Several plant species are infected by different species of the genus Agrobacterium. One problem is that no rapid and sensitive method is available for the identification of isolates of Agrobacterium at the species level. The usefulness of LMW RNA profiles for the identification of Agrobacterium species was examined. The profiles of strains belonging to the proposed species were identical to those of the type strain of each species except in two cases. In A. radiobacter, two groups of strains with different tRNA profiles were detected and in A. rhizogenes two groups with different 5S rRNA zones were found. Nevertheless, with the LMW RNA profiles it was possible to assign any isolate to one of each group within these species. The results obtained showed that all isolates studied here can be assigned to a species of Agrobacterium and hence that LMW RNA profiles offer a suitable method for the identification of tumor-inducing bacteria.     

A double-blind,randomized, placebo-controlled study of pimobendan in dogs with dilated cardiomyopathy

A double-blind, randomized, placebo-controlled study was conducted to examine the effect on heart failure class and survival of pimobendan, an oral calcium-sensitizing inodilator, in dogs with dilated cardiomyopathy (DCM). Pimobendan (0.3-0.6 mg/kg body weight/d) or placebo was administered to English Cocker Spaniels (CSs; n = 10) and Doberman Pinschers (DPs: n = 10) that had DCM in addition to background therapy of furosemide, enalapril, and digoxin. Addition of pimobendan to standard triple therapy was associated with a significant improvement in heart failure class, regardless of breed (P < .02, Mann-Whitney rank sum test). Overall, 8 of 10 animals in the pimobendan-treated group, and 1 of 10 animals in the placebo group improved their heart failure status by at least I modified New York Heart Association functional class after initial stabilization (P = .005, Fisher's exact test). Pimobendan had no significant effect on survival in the CSs (P = 0.77, log-rank test), but DPs treated with pimobendan had significantly longer survival times compared with placebo (P < .02, log-rank test), with a median survival time of 329 days in the pimobendan group compared with 50 days in the placebo group, and a hazard ratio of 3.4 (95% confidence interval 1.4-39.8). Pimobendan resulted in significant improvement in heart failure class when added to standard therapy in this group of dogs with DCM, and may have contributed to improved survival in DPs.     

Note: Current status ofBemisia tabaci in Coastal Croatia

Bemisia tabaci was first noted in Croatia in 2000, when it was identified in Split County, Dalmatia. Thirty-one plant species were identified as hosts of this pest in the central Adriatic region during 2001–2002. Four adult populations were analyzed at CIDA (Spain) by comparing a fragment of the COI gene of the mitochondrial DNA, and by examining a single microsatellitelocus. The results indicated a predominance of the Q biotype. The population dynamics ofB. tabaci was examined in outdoor conditions by observing populations fromIpomoea purpurea in 2002. The pest population appeared at the beginning of June and increased in number until its decline at the beginning of October. http://www.phytoparasitica.org posting Dec. 20, 2004.     

Survey for Haemoproteus spp., Trichomonas gallinae, Chlamydophila psittaci, and Salmonella spp. in Galapagos Islands columbiformes.

Endemic free-ranging Galapagos doves (Zenaida galapagoensis) and introduced rock doves (Columba livia) were surveyed in several islands of the Galapagos archipelago to establish sample prevalence of hemoparasites, Trichomonas gallinae, Chlamydophila psittaci, and Salmonella species. A Haemoproteus sp., the only hemoparasite identified, was found in 89% of the Galapagos doves sampled but not in the rock doves. Trichomonas gallinae was detected by polymerase chain reaction in 44% of rock doves from San Cristobal but in none of the Galapagos doves. Chlamydophila psittaci was detected from cloacal swabs in 6% of the Galapagos doves but in none of the rock doves sampled. All positive cases of C. psittaci occurred on Espa?ola, where the crude sample prevalence was 24%. A polymerase chain reaction-based Salmonella test failed to show evidence of this organism from any birds sampled.     

Structure-activity relationship studies of dibromo phenolic derivatives as photosynthetic electron chain inhibitors

A number of 2,6-dibromophenols with different substituents in the 4-position have been synthesised and their effect on the whole electron transport chain and on photosystem II have been determined. A study was made to relate the chemical characteristics of the 4-substituent group and the inhibition of the uncoupled electron transport of isolated chloroplasts from spinach plants. The chemical nature of the 4-substituent group varies greatly in the active compounds and it is therefore suggested that this group does not participate in the inhibitor-receptor interaction. The results indicated that the inhibiting power of these compounds increased with the electron-attracting capacity of the 4-substituent group, decreased with increase in its size and that there was no correlation with its hydrophobic nature.     

Spatial variability of rainfall and yield of maize in a semiarid region

The influence of nonuniform rainfall distribution patterns on the variability of maize yield and soil water use was studied with the aid of the analyses of rainfall and evapotranspiration data of a semiarid region. The analyses enabled us to define homogeneous areas of soil water availability through the application of a geostatistic algorithm developed for the computation of semivariograms, autocorrelograms and crosscorrelation functions.Water economy and yield of nonirrigated maize grown at each homogeneous area is evaluated through the application of a modification of Hanks' yield—evapotranspiration model.To optimize rainfall use by the crop under semiarid conditions, the effect of differences in soil water availability and maize varietal responses to water stress are evaluated. Results indicate that, when these differences are considered in the selection of maize cultivars, a significant increment in total regional production can be expected.     

Fruit spot of sweet lime (<Emphasis Type="Italic">Citrus limetta</Emphasis>) caused by <Emphasis Type="Italic">Septoria</Emphasis> sp. in Peru

In 2002, a severe fruit spot of sweet lime (Citrus limetta) was observed in Piura and Lambayeque provinces in northern Peru. Affected fruits showed large oval and sunken lesions, often surrounded by chlorotic haloes. Septoria sp. was isolated from affected fruits. Sweet lime isolates showed larger pycnidia and pycnidiospores than those of Septoria spp. previously described on citrus. In addition, phylogenetic analysis of the ITS sequences clearly separated the sweet lime isolates from S. citri and S. citricola. Isolates were pathogenic to detached sweet lime fruits and the fungus was isolated from lesions on inoculated fruits.     

以食品安全为饲料目标

动物饲料是食物链的开端,与食品安全有着千丝万缕的联系。霉菌毒素和细菌病原体是动物源性食品安全的主要威胁。饲料是通过营养调控方式生产安全动物源性食品的一个绝佳途径。多年来,建明欧洲公司提出了一个全方位的食品安全计划,其主要包括两个部分:通过改善饲料卫生条件避免有毒物质的影响,进行营养调控以确保食品安全。为了确保以食品安全为饲料目标就需要完整并系统地考虑这两个方面。良好的饲料卫生非常重要,不但可以减少动物接触各种毒物的风险,而且是法规要求。可以使用一种创新的干燥清洁方法——固体消毒,来保持设备和车辆的清洁。良好的饲料原料储存方法可以避免霉菌的生长和霉菌毒素的产生。在饲料生产中可以采用最佳安全模型来控制病原,这个模型考虑了诸如温度、湿度、时间、压力和强力抗菌产品(如沙门净)的用量等多种因素。这个模型涵盖了最有效和最经济的热处理和化学处理方法。饲料卫生本身并不能解决食品安全的所有问题,但却是动物源性食品安全的一个必要前提。通过饲料营养调控减少霉菌毒素和弯曲杆菌的威胁也是饲料安全的一个重要方面。研制和评估霉菌毒素结合剂的技术一直在发展(例如欧洲建明公司研制的吸附-脱附模型),但仍需要全面了解胃肠道微生物的定殖机理。有机酸在过去只是被用作饲料防腐剂或者酸化剂,而现在有机酸在调控肠道微生物菌群平衡方面起着越来越重要的作用,但使用酸化剂的目的并不相同。这是建明欧洲公司在全方位营养计划下的一个活跃的研究领域。以食品安全作为饲料目标的观点已被动物生产行业普遍接受。欧洲建明的全方位营养计划,已为生产安全的动物饲料和改善食品安全提出了一个概念性的模型,并将为全球食品安全做出重要贡献。     

Sucrolytic activities in cherry tomato fruits in relation to temperature and solar radiation

A study has been made concerning the influence of two environmental factors (temperature and solar radiation) on sugar content and sucrolytic activity in cherry tomato fruits during the crop cycle. For this, Solanum lycopersicum cv. Naomi plants were grown in an experimental greenhouse. Three fruit samples were taken over the entire production period: the first sampling at the beginning of harvest [85 days after transplanting (dat)], the second at mid-harvest (160 dat), and the third at the end of harvest (229 dat). The values for temperature and solar radiation peaked in the third sampling, coinciding with an increase in lipid peroxidation, without lowering yield with respect to previous samplings. Regarding the sugar content in the cherry tomatoes, our results showed that the increase in temperature and solar radiation diminished the sucrose content at 229 dat and raised the hexoses (glucose and fructose) as well as starch content, produced primarily by the enzyme sucrose synthase. On the contrary, the rest of the enzymes responsible for sucrose degradation, acid and neutral invertases, showed no notable changes in their activity at the end of the crop cycle. In short, our results suggest that the increase in sucrolytic activity, induced mainly by sucrose synthase under these conditions, contributes to the mechanisms of antioxidant defense by supplying precursors (glucose and fructose) of antioxidant compounds in order to restrict the massive accumulation of ROS and thereby avoid the appearance of cell necrosis and reduce yield losses.