The effect of induced autotetraploidy on resistance to clover rot (Sclerotinia trifoliorum erikss.) in red clover

In infection experiments with clover rot (Sclerotinia trifoliorum Erikss.) on 9 pairs of diploid and corresponding autotetraploid families arisen from chimaera plants the tetraploid families proved to be more resistant than their corresponding diploid families. Significant interaction between family pairs and ploidy level was demonstrated and this is an indication that there may be differences between different genotypes with respect to the effect of autotetraploidy on resistance to clover rot in red clover.

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Samenvatting Bij kunstmatige infectie met klaverkanker van 9 paren (uit chimaere planten van rode klaver afkomstige) diploide en daarmede corresponderende autotetraploide families bleken de tetraploide families grotere resistentie te vertonen dan de daarmede corresponderende diploide families.Uit een vergelijking van de families bleek dat er verschillen in invloed van de autotetraploidie op de resistentie tegen klaverkanker zijn.

     

European restructuring and changing agricultural policies. Rural self-identity and modes of life in late modernity

The main idea of this article is to present various perspectives in order to analyze the recent crisis concerning the agriculture-based rural societies in the developed capitalist communities. In all of these countries there is a production crisis, resulting in too much food. But this is also an ideological crisis, because the consumer thinks that the food is produced at too high a price. And it is a political crisis as well because a major part of the voters think subsidies and trade barriers are too high. The paper argues that beneath the present agricultural and rural policy crisis lies the failure of three great projects of our time: 1) The project of natural science; 2) The project of liberal capitalism; and 3) The project of scientific socialism. The failure of these three projects has to do with the breakdown of the positivist idea of modernization. Modernization theory was partly wrong because it overlooked the persistence of locally based life modes. Those life modes must be understood before a sustainable rural development is found. The article reviews some contemporary social science perspectives that have recently been developed to grasp the fundamental changes of today's rural societies. Based on those perspectives and primarily the life mode perspective, five key elements that are essential to analyze if we want to understand future development are isolated: food production, resources, space, social diversity, and culture.Reidar Almås is a Professor of Sociology at the University of Trondheim, Norway, where he directs the Center for Rural Research. He received his Dr. philos. at the University of Trondheim with a dissertation on group farms. Almås is now doing research on food policies, rural development, and public perception of biotechnology. In addition to several books in Norwegian, he has publishedRural Norway, a gift to Europe. Fifteen selected articles on rural persistence and change.     

Characteristics and conflicts in Norwegian agriculture

This article raises the issue of the extent to which a single nation can develop a “national agricultural policy,” pursuing internal goals in agrarian development, goals that vary significantly from those of other industrialized countries. What are the conflicts arising from such a policy and how do these conflicts interfere with the general agricultural crisis of these countries? The Norwegian case is explored as an example of a blend of social-democratic and center-populist agricultural policies. The decision in 1975 by the Norwegian Parliament to establish the income level of farmers at the same level as workers is seen as an experiment. As agricultural policy, this new departure represented a deviation from the earlier policies of rationalization. The Social Democrats developed their new position as a result of internal and external pressure. A series of reforms financed by the new state incomes from oil production were undertaken, of which income equalization and a farm relief service were the most important. Most Norwegian farmers speak of the reform years as “the good years of escalation.” Equity was reached in 1982, but nevertheless several problems emerged: 1) the escalation of subsidized incomes led to overproduction and decreasing incomes from the market (after 1982), 2) the large budgetary transfers to agriculture caused a legitimation crisis, fueling the constituency of the right-wing Progress Party, 3) the large subsidies to agriculture contributed to the fiscal crisis of the state, 4) the problems mentioned above, contributed to the general crisis of the Norwegian Social Democracy which finds itself with dwindling support. The likely outcome of the present Norwegian farm crisis is the implementation of an agricultural policy that will protect the most vulnerable sector and open the more competitive sector to market forces.     

Assessment of Carbon Balance in Community Forests in Dolakha, Nepal

This study assessed the net above-ground carbon stock in six community forests in the Dolakha district, Nepal. A survey was conducted of above-ground timber species, using random sampling. A tree-ring chronology for Pinus roxburghii was created to construct a growth model representative of the various mainly-pine species. The allometric model combined with tree ring analysis was used to estimate carbon stock and annual growth in the above-ground tree biomass. The out-take of forest biomass for construction material and fuelwood was estimated on the basis of interviews and official records of community forest user groups. The average annual carbon increment of the community forests was 2.19 ton/ha, and the average annual carbon out-take of timber and fuelwood was 0.25 ton/ha. The net average carbon balance of 1.94 ton/ha was equivalent to 117.44 tons of carbon per community forest annually. All the community forests were actively managed leading to a sustainable forest institution, which acts as a carbon sink. It is concluded that community forests have the potential to reduce emissions by avoiding deforestation and forest degradation, enhance forest carbon sink and improve livelihoods for local communities.     

Parallelism in thermal growth response in otoliths and scales of brown trout (Salmo trutta L.) from alpine lakes independent of genetic background

Low density in natural populations of salmonids has predominantly been managed by stocking of non‐native conspecifics. Due partly to domestication, introduced non‐native fish may be maladapted under natural conditions. Interbreeding between introduced and wild individuals may therefore impair local adaptation and potentially population viability. Brown trout (Salmo trutta L.) from three headwaters (with stocked fish) and three interconnected lakes (with native fish) on the Hardangervidda mountain plateau, southern Norway, were tested for differences in thermal effects on scale and otolith growth. Otolith and scale annuli widths from immature brown trout showed positive correlation with mean annual summer temperature for all six sampled populations. In mature individuals, a similar positive thermal correlation was evident for the otoliths only. Interannuli width measurements from scales indicate a halt in somatic growth for brown trout in this alpine environment when reaching ages between 7 and 9 winters, coinciding with age at maturity. Our study indicates that otolith growth follows summer temperature even when individuals do not respond with somatic growth in these populations and that introduced brown trout and introgressed populations have similar thermal growth responses. Due to the continued otolith growth after stagnation in somatic growth and the impact of fluctuations in summer temperature, the utilisation of otolith annuli widths for back calculation of length at age should be treated with caution.     

Quality of raw and smoked fillets from clinically healthy Atlantic salmon,Salmo salar L., following an outbreak of pancreas disease (PD)

Pancreas disease (PD) is a viral disease of farmed salmonid fish, which causes huge economic losses. Pathological changes in skeletal muscle, pancreas and heart are hallmarks of PD. Stakeholders in the fish‐smoking industry have claimed that fillets from PD‐affected Atlantic salmon, Salmo salar L., are of poor quality. We therefore examined harvest‐ready, clinically healthy Atlantic salmon from a population of fish previously affected by PD. Histopathological changes in skeletal muscle tissues ranged from minor to severe. Fillet quality measurements showed that fish with severe skeletal muscle changes provided a paler raw fillet and a yellowish and harder cold‐smoked fillet than normal. PD had no significant effect on fillet gaping, bacteriological quality or off‐odour development during storage. An unexpected finding was a significant subendocardial fibrosis in 23% of the PD‐affected fish. The latter may indicate susceptibility to stress‐related heart failure.     

In vitro studies of Lactobacillus delbrueckii subsp. lactis in Atlantic salmon (Salmo salar L.) foregut: tissue responses and evidence of protection against Aeromonas salmonicida subsp. salmonicida epithelial damage

Probiotic bacteria increase the host health status and protect mucosal tissue against pathogen-caused damage in mammalian models. Using an in vitro (intestinal sac) method this study aimed to address (a) the in vitro ability of Lactobacillus delbrueckii subsp. lactis to remain in the gastrointestinal tract of Atlantic salmon (Salmo salar L.) and (b) its ability to prevent cellular damage caused by successive incubation with Aeromonas salmonicida subsp. salmonicida the causative agent of furunculosis. Short in vitro incubation of salmon foregut with (TRITC)-labelled L. delbrueckii subsp. lactis showed that the probiont was able to colonize the enterocyte surface as studied by confocal microscopy. Furthermore, foregut incubated with the probiotic bacteria only, resulted in a healthy intestinal barrier whereas exposure to A. salmonicida disrupted its integrity. However, pre-treatment of salmon intestine with L. delbrueckii subsp. lactis prevented Aeromonas damaging effects. These results are promising in the context of the use of non-autochthonous probiotic bacteria as prophylactic agents against fish bacterial infections in the gastrointestinal tract.     

Coral reef growth in the galapagos: limitation by sea urchins

The regular echinoid Eucidaris thouarsii is a conspicuous omnivore on coral bottoms in the Galápagos. Unlike Eucidaris in Panama and mainland Ecuador, Galápagos Eucidaris are large and abundant and graze heavily in the open on live corals day and night. These differences are probably due in large part to more intense predation by fishes on mainland compared with island urchin populations. An assessment of coral growth versus coral attrition from grazing shows that Eucidaris interferes with the establishment of pocilloporid reef frame and therefore reduces reef growth in the Galápagos.