Geographic distribution and genetic resources of Dactylis in Galicia (northwest Spain)

Three Dactylis glomerata subspecies can occur in Galicia (Spain): subsp. glomerata, subsp. izcoi and subsp. marina. The second includes diploid and tetraploid populations adapted to acid soils. The third subspecies comprises natural tetraploid populations mainly on sea cliffs, with high digestibility. Dactylis taxonomy is difficult due to the existence of different ploidy levels and to free hybridization at the tetraploid level. This difficulty increases in Galicia, where there is a rich flora with relics and hybrids. The advance of human technology makes necessary the collection of natural Dactylis resources. In this paper, Dactylis distribution in Galicia is described. Tetraploid populations from subsp. izcoi have a wider ecological range than diploids (Galician diploid). These diploids and the subsp. marina are more widespread than formerly recognized. Morphologically, subsp. glomerata and izcoi are more similar than hitherto reported. It is suggested that the subspecies are adapted ecotypes which hybridize. They are useful genetic resources for pasciculture on acid soils and agroforestry.     

Die Bedeutung der freien Aminosäuren der pflanzlichen Erzeugnisse in der Ernährung

Zusammenfassung Die Verteilung der freien Aminosäuren in Ungarn und in den Tropen gezüchteter Gemüse und Obstarten wurde Untersucht.Obst is gewöhnlich arm an freien Aminosäuren und deshalb spielt es in der Versorgung mit essentiellen Aminosäuren nur eine bescheidene Rolle.Die Gemüsearten in Ungarn sichern bei Berücksichtigung des Jahresverbrauchs den Bedarf an verschiedenen essentiellen Aminosäuren für 25 bis 144 Tage. Der Anteil der essentiellen Aminosäuren erreicht jedoch nicht den Optimalwert.Während der Reifung einiger Obstarten, z.B. Bananen, Tomaten, kann der Gehalt an freien Aminosäuren auf etwa das Doppelte ansteigen.

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The nutritional importance of free amino-acids in plant products

The free amino acid pattern of plants grown in Hungary and the same tropical species showed a strong similarity in identical phases of ripening. The total free amino acid content of some fruits, e.g. bananas or tomatoes, may be doubled during ripening.The examined fruits were, in general, poor in free amino acids, thus, they play only a very subordinate role in our supply of essential amino acids.Taking into account the annual consumption in Hungary, the consumed vegetables cover the requirement of the various essential amino acids for 25 to 144 days. However, the proportion of the essential amino acids does not attain the optimum value.

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Résumé L'auteur a étudié la répartition des acides aminés libres des plantes cultivées en Hongrie à celles des mèmes espèces tropicales. On a trouvér — dans les phases identiques de maturité — une grande ressemblance.Les fruits sont généralement pauvres en aminoacides libres et ils ne jouent qu'un rôle peu important dans la satisfaction de nos besoins.Les légumes, en tenant compte de la consommation annuelle en Hongrie, assurent les besoins en aminoacides essentielles pour 25 à 144 jours, mais le rapport des aminoacides essentielles ne correspond pas au rapport optimal.Dans quelques fruits, p.e. les bananes ou les tomates, la teneur totale en aminoacides peut se redoubler lors du mûrissement.

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Vortrag, gehalten auf der gemeinsamen Tagung der Internationalen Vereinigung zur Erforschung der Qualität von Nahrungspflanzen (CIQ) und der Deutschen Gesellschaft für Qualitätsforschung (Pflanzliche Nahrungsmittel) e.V. (DGQ) in Berlin am 6. Oktober 1972.     

Potato virus Y (PVY) in Seed Potato Certification

Journal of Plant Diseases and Protection - In the EU and many other countries worldwide, seed potatoes require certification to be marketed. In most of the European national and international seed...     

Impact of Stolbur Phytoplasmas on Potato Tuber Texture and Sugar Content of Selected Potato Cultivars

Potato stolbur is a phytoplasmal disease that seriously affects yield and tuber quality in South Eastern Europe, Russia and the Mediterranean areas. In 2007 and 2008, field experiments were carried out to determine stolbur resistance of processing potato cultivars at Sannicolau Mare (Romania) by determining consistency and concentration of reducing sugars (fructose and glucose), sucrose and phytoplasmas in potato tubers. In both years, non-symptomatic potato tubers showed sucrose levels in the range of 3,000 mg kg⁻¹ fresh weight (FW). In contrast, sucrose concentrations were up to 11,820 mg kg⁻¹ FW in 2007 and 19,560 mg kg⁻¹ FW in 2008 in tubers showing severe symptoms. These high values severely affect suitability of tubers for processing as sucrose serves as substrate for the formation of reducing sugars that are the limiting factor in fried potato production for Maillard-related discolouration. The cultivars examined differed considerably in susceptibility to stolbur disease. Whereas cvs. ‘Courage’ and ‘Lady Rosetta’ showed high numbers of diseased tubers and high sucrose concentrations, ‘Lady Claire’ had a lower incidence of symptomatic tubers and lower sucrose concentrations. However, fully resistant cultivars were not observed. Across all cultivars examined, phytoplasmal concentration was significantly higher in symptomatic tubers than in non-symptomatic ones.     

Ecosystem service supply and vulnerability to global change in Europe

Global change will alter the supply of ecosystem services that are vital for human well-being. To investigate ecosystem service supply during the 21st century, we used a range of ecosystem models and scenarios of climate and land-use change to conduct a Europe-wide assessment. Large changes in climate and land use typically resulted in large changes in ecosystem service supply. Some of these trends may be positive (for example, increases in forest area and productivity) or offer opportunities (for example, "surplus land" for agricultural extensification and bioenergy production). However, many changes increase vulnerability as a result of a decreasing supply of ecosystem services (for example, declining soil fertility, declining water availability, increasing risk of forest fires), especially in the Mediterranean and mountain regions.     

Conditioning Horses at v10 3 Times per Week Does Not Enhance v4

This study examined the effect of exercising horses 3 times per week with two bouts of 5-minutes' duration at their v₁₀. Six Thoroughbreds were treadmill-conditioned for 6 weeks. A standardized exercise test (SET) was performed at the beginning of the conditioning period to determine the blood lactate–running speed (BLRS) relation, and the SET was repeated every 2 weeks. After each SET, the BLRS relation was used to calculate the horse's speed, which produced a blood lactate (LA) concentration of 10 mmol/L (v₁₀) and 4 mmol/L (v₄). Each horse was then conditioned for the next 2 weeks (3 times/week) at its individual v₁₀ for two 5-minute bouts with a 5-minute walking phase in between. Exercise speed was individually adapted to the new v₁₀ every 2 weeks. The v₄ of horses decreased after the first 2 weeks (from 6.23 ± 0.41 m/s to 5.95 ± 0.33 m/s, mean ± SD; P < .05), increased in the following 2 weeks (6.33 ± 0.58 m/s; P < .01), and stayed constant thereafter (P > .05). The conclusion drawn was that exercising horses 3 times per week at their v₁₀ for two 5-minute bouts did not improve v₄.     

Multipurpose conversion management of Scots pine towards mixed oak–birch stands—A long-term simulation approach

The forest growth model 4C was used to investigate how conversion management of a Scots pine (Pinus sylvestris L.) stand towards a mixed oak–birch stand would affect stand structural development – and hence biodiversity and productivity – in the long term. For this purpose the 4C model was parameterised for natural regeneration of light demanding species and extended for management of multi-layered stands. A series of structural indicators was selected to describe key factors of forest biodiversity at the stand scale. Two consecutive aspects of Scots pine conversion were tested: (1) the choice of conversion strategy between thinning and gap creation and (2) the choice of conversion regime in terms of cutting cycle, thinning type and pine tree retention. Three simulated conversion strategies aim at the gradual removal of the pine canopy but differ in the spatial organisation of pine cuttings and hence result in different light conditions for regeneration. Only the directed gap creation strategy was able to maintain and increase birch admixture to the stand and to approach natural stand structural development. Simulation of 12 conversion regimes for the directed gap creation strategy indicated that thinning type (from above or from below), pine tree retention at final felling (50% of the standing volume or none) and cutting cycle (6, 9 or 12 years) all significantly influence stand structural development. These effects were clearest for oak development. Birch occurred in a few mixed clusters, but tended to disappear when longer cutting cycles were used. Based on a multi-criteria analysis we conclude that the optimal conversion regime – in which both stand productivity and biodiversity objectives can be combined – implies thinning from above, pine tree retention, and cutting cycles of 6 years. The conceptual validity of the model as well as the applicability of the results are discussed.