Genetic relationships among resynthesized,semi-resynthesized and natural <Emphasis Type="Italic">Brassica napus</Emphasis> L. genotypes

The allopolyploidization event that created cultivated oilseed rape Brassica napus L, followed by intense breeding, reduced its genetic diversity. Resynthesized (RS) B. napus L. obtained by interspecific hybridization between genotypes of B. rapa L. and B. oleracea L. can be a valuable source for broadening genetic diversity in cultivated oilseed rape. In this study, we determined the extent of DNA polymorphism among natural accessions of oilseed rape, resynthesized B. napus, their parental species and double-low quality semi-RS lines carrying the Rfo gene. Using 10 selected primer combinations, 522 polymorphic AFLP markers were scored in the complete set of 100 Brassica sp. To detect relationships between these genotypes, a cluster analysis was performed using the Jaccard’s distance. Resynthesized allopolyploids clustered directly between their diploid parents. Cultivated accessions of oilseed rape created a compact group away from resynthesized allopolyploids as well as semi-RS lines. The natural oilseed rape group, which consists of 49 cultivars and breeding lines of oilseed rape, is characterized by lower genetic diversity than the group of 33 accessions of resynthesized oilseed rape, and the analysis showed that the double-low quality semi-RS lines represent a specific genetic variation of B. napus. The de novo resynthesized B. napus lines and the semi-RS lines of double-low quality generated from them, provide a significant opportunity for enrichment the gene pool of oilseed rape.     

Late nitrogen fertilization affects carbohydrate mobilization in wheat

An experiment was carried out to determine how the late application of nitrogen (N) fertilizer affects the use of pre‐anthesis carbon reserves during the grain‐filling period of pot‐grown wheat with no water shortage. Increasing doses (equivalent to 0, 140, and 180 kg N ha^–1) of N fertilizer were applied, either in two amendments (stages GS20 and GS30) or in three amendments (stages GS20, GS30, and GS37, according to Zadoks scale). The management of fertilizer by combining an increased N rate with late N application was able to stimulate canopy development, to raise photosynthetic capacity and carbohydrate accumulation during the vegetative stages, and to increase grain yield. Based on the dynamics of carbohydrate accumulation in the ear, three phases were differentiated during the grain‐filling period, whose temporary pattern remained stable regardless of the fertilizer management. The net remobilization of carbohydrates started 12 d after anthesis from the leaves and 28 d after anthesis from roots and stems. The increase of the N dose with late N application allowed on one hand a lower use of the pre‐anthesis carbon reserves in favor of greater de novo photosynthesis during the grain‐filling period, and on the other hand greater relative contribution of the leaf and ear C reserves to remobilization towards the grain. Further splitting the dose increased only the relative contribution of ear C reserves. The stem contribution seemed to be independent of N applied whereas the root contribution tended to diminish with late N application.     

UTILITY OF MAGNETIC RESONANCE IMAGING FOR DISTINGUISHING NEOPLASTIC FROM NON-NEOPLASTIC BRAIN LESIONS IN DOGS AND CATS

The aim of this study was to identify magnetic resonance (MR) signs that aid differentiation of neoplastic vs. non-neoplastic brain diseases in dogs and cats. MR images of 36 dogs and 13 cats with histologic diagnosis of intracranial disease were reviewed retrospectively. Diagnoses included 30 primary and three metastatic brain tumors, 11 infectious/inflammatory lesions, three vascular, one degenerative disease, and one developmental malformation. Upon univariate analysis of 21 MR signs, there were seven that had a significant association with neoplasia: single lesion (P = 0.004), shape (P = 0.015), mass effect (P = 0.002), dural contact (P = 0.04), dural tail (P = 0.005), lesions affecting adjacent bone (P = 0.008), and contrast enhancement (P = 0.025). Increasing age was also found to be associated with neoplasia (P = 0.0001). MR signs of non-neoplastic brain diseases in dogs and cats were more variable than those of brain neoplasia.     

Taenia solium oncosphere antigens induce immunity in pigs against experimental cysticercosis

Immunity to Taenia solium infection was investigated using an experimental intramuscular oncosphere infection assay (IMOA) model in pigs. Three naturally infected pigs with cysticercosis were treated with oxfendazole (OFZ), a drug demonstrated to kill cysts in porcine muscle. These animals were then challenged with oncospheres but did not develop any cysts while three uninfected pigs that were similarly challenged, did develop intramuscular cysts. In another study, two groups of three pigs each were immunized with crude T. solium oncosphere and metacestode antigens, respectively, and tested with the IMOA. Immunization with crude oncosphere antigens (OAs) induced 100% protection, while metacestode antigens provided only partial protection. Immunoblots showed that pigs with complete immune protection to oncosphere intramuscular challenge had antibodies to two OAs at 31.3 and 22.5 kDa, respectively. Antibody to these two antigens was absent in pigs immunized with metacestodes or in uninfected control pigs. This study demonstrated the presence of two antigens that are unique to the oncosphere. Although, antibody to these two antigens is consistently present in pigs that are protected from an oncosphere intramuscular challenge their role in preventing infection by T. solium larval cysts is still hypothetical.     

Host specificity of abomasal nematodes in free ranging alpine ruminants

Abomasums from 641 alpine wild ruminants representing five different species (Cervus elaphus, Capreolus capreolus, Rupicapra rupicapra, Capra ibex, Ovis musimon) and from 19 domestic sheep (Ovis aries) from alpine areas were examined in order to investigate the host-specificity of abomasal helminths. Nine out of 20 helminth species were found in at least five different host species. A discriminant analysis was able to significantly discriminate the hosts on the basis of their helminth community composition with the exception of O. musimon and O. aries. Based on the correlation between each variable represented by helminth species with the most explanatory discriminant axis, it was possible to classify helminths into specialists and generalists. Specialists are represented by the dominant species in a community of an host species or family while generalists appear in the communities of many different hosts as intermediate species. Due to the pathogenic potential of some of these generalist species (i.e. Haemonchus contortus, Trichostrongylus axei) and their ability to adapt easily to the conditions found in several different hosts, they appear to be the most important from a sanitary point of view.     

Detection of hepatitis E virus shedding in feces of pigs at different stages of production using reverse transcription-polymerase chain reaction.

The aim of this study was to determine at which production stages hepatitis E virus (HEV) is shed by the highest number of pigs and to estimate the relative risk associated with each stage. For this purpose, 146 fecal samples of pigs from 21 farms were studied. In addition, 1 sample from the manure ditch and another sample of drinking water, collected directly from the trough located in the pen, were taken from 16 farms. HEV RNA was detected in fecal samples from 34 pigs (23.29%). The production stages in which most pigs excreted HEV were weaners (41.7%) and pigs in the first month of feeding (60%). The results of the statistical analysis showed that the principal significant risk stage in HEV shedding was the first month of feeding (odds ratio [OR] 19.5, 95% CI 3.59-106.07, P = 0.001) followed by the weaners stage (OR 9.3, 95% CI .78-48.42, P = 0.008). In 8 out of 16 farms tested (50%) HEV RNA was detected in raw manure and in the water trough of only 1. Detection of HEV in manure ditches raises the concern of how to deal with manure of swine origin, because it is used as soil fertilizer.     

Drought responses of six ornamental herbaceous perennials

Although low water use landscaping is becoming common in arid regions, little is known about drought tolerance and drought responses of many ornamental plants, especially herbaceous perennials. Drought responses were assessed for six herbaceous ornamental landscape perennials in a 38 l pot-in-pot system in northern Utah over a 2-year period. The first year was an establishment period. During the second year, drought responses were evaluated for established Echinacea purpurea (L.) Moench, Gaillardia aristata Pursh, Lavandula angustifolia P. Mill., Leucanthemum × superbum (J.W. Ingram) Berg. ex Kent, ‘Alaska’, Penstemon barbatus Roth var. praecox nanus rondo, and Penstemon × mexicali Mitch. ‘Red Rocks’. Plants were irrigated at frequencies of 1 (control), 2, or 4 weeks between June and September, simulating well-watered conditions, moderate drought, or severe drought. Osmotic potential (Ψ_s), gas exchange, visual quality, leaf area, and dry weight were assessed. In a confined root zone, P. barbatus showed the greatest tolerance to all levels of drought, avoiding desiccation by increasing root:shoot ratio and decreasing stomatal conductance as water became limiting. L. angustifolia and P. × mexicali showed tolerance to moderate drought conditions, but died after exposure to the first episode of severe drought. Neither G. aristata nor L. superbum were able to regulate shoot water loss effectively. Instead, both species displayed drought avoidance mechanisms, dying back when water was limiting and showing new growth after they were watered. Compared to control plants, G. aristata shoot dry weight was reduced by 50% and 84%, and L. superbum shoot dry weight was reduced by 47% and 99% for the 2- and 4-week irrigation intervals, respectively. Root dry weights were affected similarly for both species. E. purpurea exhibited poor visual quality at all irrigation intervals, in particular wilting severely in both drought treatments, but regaining turgor when watered again. P. barbatus is recommended for ornamental landscapes that receive little or no supplemental irrigation, while E. purpurea is not recommended for low water landscapes because of low visual quality under even mild drought.     

Bridging the Gap between Centrally Defined Policies and Local Decisions – Towards more Sensitive and Creative Rural Landscape Management

European policies and instruments such as the Common Agricultural Policy (CAP) and many instruments for nature and landscape conservation in Europe have for some decades been dominated by centralisation and standardisation. This paper shows that this has led to the neglect of contextual and place-related approaches and an unnecessarily high degree of over-simplification. Recently, as a reaction to this over-simplification, diversity and specific character has been particularly stressed in many European and national strategies for rural landscapes and conservation, but the processes of simplification still continue. Using examples from mixed agriculture and forestry landscapes in Portugal, Slovenia and Sweden, this paper aims to contribute to understanding the gap between centrally defined strategies for rural landscapes and awareness and management practices at local level. The three countries are situated at the outer fringes of Europe, and are complementary with their different degrees of urbanisation, forest distribution and tree-richness in the agricultural landscapes. Furthermore, the aim is to show how local landscape management is driven and to identify factors contributing to a better use of public policies through a participatory process with visions for the future. Systems of landscape classifications such as landscape character assessment often recognise the specific character of these landscapes, but have so far achieved very little for the preservation of their locally specific values, nor have they contributed to the development and the creation of new visions for future management. Such systems could contribute much more if they could be opened to adaptation on a more local scale in communication-led management planning.