The plant tissue culture collection at the Department of Botany, University of Debrecen

We present a list of tissue culture systems developed at the Department of Botany, University of Debrecen. Several of tissue cultures were developed for the first time in our laboratory. These include micropropagation of Elatine hungarica, callus cultures of several oak genotypes of Hungarian origin and of Crocus species characteristic for the Carpathian Basin. Callus cultures were either organogenic (e.g. Crocus scepusiensis) or embryogenic (Quercus petraea, Galanthus and Crocus species, Phragmites australis). In case of embryogenic cultures, somatic embryos showed either normal, bipolar development (e.g. Crocus heuffelianus, Phragmites australis) or they have lost this bipolarity at the maturation of embryos (C. banaticus, C. sativus,Galanthus). The type of callus is yet to be identified for several cultures (e.g. Plantago lanceolata, Vicia faba). Most of our in vitro cultures proved to have plant regeneration potential. Several of them derived from endangered/ red list plants (Crocus species, Elatine hungarica, Galanthus nivalis), therefore they are suitable for germplasm preservation. Others (Quercus, Phragmites australis) proved to be suitable for stress physiology and/ or cell biology experiments. Cultures such as Crocus sativus or Plantago lanceolata derived from plants of medicinal importance, therefore are of potential pharmacological use

Effect of large- and small- bodied zooplankton on phytoplankton in a eutrophic oxbow

Macrozooplankton and microzooplankton effects on the phytoplankton were measured in situ in a eutrophic lake. Indigenous phytoplankton were incubated for 5 days in 301 mesocosms with either the macro- and microzooplankton (complete), microzooplankton only (micro) or no zooplankton (none). Changes in phytoplankton biovolume were investigated. Rotifer densities became significantly higher in the 'micro' treatment than in the 'complete' and 'none' treatments. Total algal biovolume changed little in the 'complete' and 'none' treatments, but increased significantly in the 'micro' treatment. The results suggest that macrozooplankton (Daphnia magna) suppressed it and microzooplankton (Keratella cochlearis) enhanced it. They had opposite net effects on the phytoplankton. Suppression of microzooplankton by Daphnia probably had an indirect negative effect on the phytoplankton

The Role of Organic Agriculture in Rural Development

Rural development includes local population, its way of life, employment characteristics, income structure, dwelling conditions, service levels as well as cultural aspects just as traditional handcrafts, dishes, language, clothing and habits. Since agriculture is a historically determining economic activity in rural areas its effects primarily determines the rural ways of life. New rural development policy of EU can be featured by multisectoral and integrated approach. Organic farming is based on the definition of ecology as former namings just as ˝ecological˝, ˝biological˝ represent it. Its basic aim is ensuring sustainable development whereas it uses again, from time to time to locally available reserves. Among basic principles of organic farming can be found the protection of soil and environment and this implies the usage of natural capacities of plants, animals and the landscape and willingly tries to improve the quality of the environment. It can be stated that market demand for organic products is the strongest in Europe, as much as 46% of the world´s organic product output is sold in this continent which possibly can be explained by its economic development level. This overall development reached Hungary, too. In December 2002 the estimations showed 105.000 ha and within this 54.497 ha had been registered as approved organic area. During the last year we carried out two focus group analyses examining the reasons for buying or not buying organic foods. In the presentation the most important results of the two focus groups will also be introduced in details

The Role of Organic Agriculture in Rural Development

Rural development includes local population, its way of life, employment characteristics, income structure, dwelling conditions, service levels as well as cultural aspects just as traditional handcrafts, dishes, language, clothing and habits. Since agriculture is a historically determining economic activity in rural areas its effects primarily determines the rural ways of life. New rural development policy of EU can be featured by multisectoral and integrated approach. Organic farming is based on the definition of ecology as former namings just as ˝ecological˝, ˝biological˝ represent it. Its basic aim is ensuring sustainable development whereas it uses again, from time to time to locally available reserves. Among basic principles of organic farming can be found the protection of soil and environment and this implies the usage of natural capacities of plants, animals and the landscape and willingly tries to improve the quality of the environment. It can be stated that market demand for organic products is the strongest in Europe, as much as 46% of the world´s organic product output is sold in this continent which possibly can be explained by its economic development level. This overall development reached Hungary, too. In December 2002 the estimations showed 105.000 ha and within this 54.497 ha had been registered as approved organic area. During the last year we carried out two focus group analyses examining the reasons for buying or not buying organic foods. In the presentation the most important results of the two focus groups will also be introduced in details

Expression of claudins in the normal canine gastric mucosa

The aim of the present study was to investigate the expression pattern of claudin-1, -2, -3, -4, -5, -7, -8, -10 and -18 in the intact fundic and pyloric gastric mucosa of dogs. Intense, linear, membranous claudin-18 positivity was detected in the surface gastric cells and in the epithelial cells of the gastric glands both in the fundic and pyloric stomach regions. The mucous neck cells in the apical part of the glands, furthermore the parietal cells and chief cells of the basal part of the gland were all positive for claudin-18, in the same way as the enteroendocrine cells. Cells of the basal part of the pyloric glands showed intense, linear, membranous claudin-2 positivity, but cells of the superficial portion of these glands and the surface gastric cells in this region were claudin-2 negative. Fibroblasts, endothelial cells, lymphocytes of the propria layer, smooth muscle cells and vegetative neurons were all negative for claudin-2. All gastric epithelial cells were negative for claudin-1, -3, -4, -5, -6, -7, -8 and -10. The endothelial cells of the propria layer had intense claudin-5 positivity. We assume that claudin-18 forms a paracellular barrier against gastric acid in the healthy canine stomach, in the same way as in mice

Multi-Frequency Electrical Impedance Measurement on a Wooden Disc Sample

Abstract Non-invasive measurement techniques are widely used for the investigation of living tree and wood material. Principles and methods from other fields of science form the basis of these techniques. Electrical impedance measurement, which is adopted mainly from applied geophysics, plays an important role in the investigation of living trees and wood material. Unlike other measurement techniques that provide mainly physical information, electrical impedance measurement is able to gather either physical or chemical information. There are several published accounts of the use of Electrical Impedance Tomography mainly for examining internal decay, estimation of sapwood, and heartwood width. The advantages of the method are its low costs and rapid execution; however, low spatial resolution is still one of the most glaring limits of the method. Use of a new, self-developed, high resolution measurement system provides new opportunities to gain better insights into the characterisation of wood material. As well as high accuracy and resolution, the measurement system is able to operate in a wide frequency range. This expands the examined parameters making it possible to extend the gained information and develop new methods for the investigation of living trees and wood material. The aim of our publication is to introduce some experimental results in the investigation of spatial resolution our system measured on a wooden disc.</jats:p