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Complex assessment of inland water fish stocks
74-80Views:337In the domestic fish production, natural waters have yielded for several years about 7-8 thousand tons. This, from the point of view of outputs, considering the almost 130 thousand hectares of natural water, is rather low, it means approximately 55-60 kg/ha mixed fish.Although the various natural waters can differ significantly on the basis of yields, yet on the majority of the territories, the results were low. In the case of our extensive still waters and rivers, the reason can undoubtedly be found in the combined effect of the lack of the possibility of reproduction of the fish stock and the over-fishing. Fishery built on planning supposes the best possible knowledge in the given circum stances of the parameters of the water area and its fishstock. Lacking this knowledge, it is not possible to establish the optimal use fulness of the resources, what is more, the management can make faulty decisions – as a result of a lack of information -, which can risk the success of later activities.
It is known that many factors have an impact on the success of the fishery, as well as some information in connection with the water area and the fish stock are necessary, the knowledge of which make it possible to manage the fishery in a planned way. One part of the information is available, while the other part is incomplete or not deep enough. The necessary data are dissimilar depending on their nature, can be obtained from different places, by different methods.
As the first step for executing the field surveys and processing data, I developed a complex model, which contains in a unified system the steps of estimating the fishstock. I made the sampling on the basis of this. Part of the model is a fish faunistic survey, as well as a morphological survey of the water area. The information gained from these are important for making more accurate the system of devices of the samplings for stock estimation (duration, number of net-rows) and for assigning its place (places representing the best way the physical characteristics of the given water area). The major stages of stock-survey: A) faunistic survey, B) physical survey of the bed, and C) sampling with the help of gill-nets. This is followed by the evaluation by the computer module.
The results of the research create a methodological and technical background for the fish faunistic and population biologic surveys still performed in different ways in our country, and by applying these methods together, all basic information about natural waters which help decision-making concerning fisheries can be obtaine deffectively. -
Micropropagation of Leuce-poplar clones and its role in selection breeding
43-48Views:370Leuce-poplars (mostly white poplar and its natural hybrid grey poplar) are native tree species trough Hungary. They are covering more than 4.0 per cent of the Hungarian forested area (77 000 ha). The white (grey) poplars play a significant role in the forestation under sandy soil site conditions as well as they are of importance from nature conservation point of view as well.Long-term selection breeding work is going on at the National Agricultural Research and Innovation Centre Forest Research Institute (NARIC FRI), involving selection of fast-growing Leuce-poplar clones under dry site conditions.Micropropagation technology is relatively quickly spreading in forestry. In vitro multiplication of trees is applied mainly in fruit growing in Hungary, in case of forestry it is used mainly for selection breeding.This paper presents a short overview on the micropropagation trials with different Leuce-poplar clones and the early evaluation of the seedlings growing of the micropropagated clones/varieties. -
The recent state of cryopreservation techniques for ex-situ gene conservation and breeding purposes in small ruminants: A review
81-87Views:550The viewpoint of the recent cryopreservation techniques (CT) suggests the use of a reduced volume of cryopreservation solution, high concentration of cryoprotectants and ultra-rapid cooling and warming rates help to reduce cryo-injury and maximize the viability of the preserved animal genetic resources (AnGR). The CT had now become widely accepted as one of the best methods of choice for the ex-situ conservation of AnGR due to its high success rate recorded and no-invasive nature as compared to the conventional slow rate freezing (CSRF). Rapid advances and wide acceptability of the use of assisted reproductive technologies (ART’s) particularly artificial insemination (AI) in animal breeding had resulted in a greater loss of a large number of good quality genes in virtually almost all the native breeds of animals across the globe. Small ruminant (SR) animals are not an exception in such present predicaments situation of erosion and dilution of the valuable AnGR among the native breeds. As a result of this, 148 and 16 breeds of sheep and goats respectively have already become extinct in Europe and the Caucasus. In view of the aforementioned situation, the present review aimed at exploring some of the current states of development, roles played and potentials of CT in the conservation of SR genes and genome for the immediate and future breeding purposes for sustainable development. It basically covers; animal genetic resource, the need to conserve AnGR, tools for ex situ in vitro conservation of AnGR and recent developments in breeding and cryopreservation of SR AnGR.
Cryopreservation is playing a pivotal role in ex-situ gene conservation of AnGR. Decline in genetic diversity among SR breed population was high in Europe and the Caucasus. There is therefore, need for improvent on current stringent measures on conservation of AnGR in this region of the world.
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A partial botanical survey of a gamepreserve
27-30Views:474Hungary is internationally well known for its high level game management. An important part of game management is indoor game keeping. In Hungary more and more game preserves were founded all over the country. The role of these game preserves to retain forest stands outside of the closed area. According to the law, in the game-preserves the game bearing capacity is not the most important parameter, because in these areas the feeding is continuous. In practice it means that in game-preserves we find a much higher density of games than in nature. This causes a relative big loading of the area (of the herbaceous and arboreal), where the game-preserves are located. Our aim is to study the ecological and management issues of forest- and game resources. The scene of these work is a game-preserve related to the Nyírerdő Corporation (Nyíregyháza).
We have done a botanical survey (plant coverage, life-form spectrum) in the three previous units and in the control area (outside of the game-preserve) as well. Our results show the difference in case of the state of herbaceous plants between areas with higher and lower game density. -
Andrological examination of Hungarian Large White and Landrace boars
5-10Views:379The Hungarian Large White and Hungarian Landrace pig breeds have outstanding lifetime performance, production parameters and crossbreeding ability. Nevertheless, during the recent decades, these breeds could not compete with the West European hybrid pigs concerning on production results. In this study, we made a complex andrological evaluation of boars in different Hungarian nucleus breeding stocks. After taking blood and semen samples, performing gonadotropin-releasing hormone (GnRH) challenge, ultrasonic and thermographic examinations were done. Laboratory tests were accomplished in reproduction labs of NARIC ABNMS. Our goal was to determine the reproductive performances of boars and collect samples for future genetic examinations, respectively.