Karotten von der Saat bis zum Teller - Einfluss von Sorte Standort, Jahr und Anbauweise auf den Mineralstoffgehalt

Wie wertvoll sind Karotten für unsere Ernährung? Die Fachwelt ist sich einig, dass der tägliche Konsum von Früchten und Gemüse erhöht werden soll. Es gibt jedoch Presseberichte, die den ernährungsphysiologischen Wert von heutigem Gemüse hinterfragen. Die Rolle der Karotte als Mineralstoffquelle wird durchleuchtet

VLT observations of metal-rich extra galactic HII regions. I. Massive star populations and the upper end of the IMF

We have obtained high quality FORS1/VLT optical spectra of 85 disk HII regions several nearby spiral galaxies. Our sample of metal-rich HII regions with metallicities close to solar and higher reveal the presence of Wolf-Rayet (WR) stars in 27 objects from the blue WR bump and 15 additional candidate WR regions. This provides for the first time a large set of metal-rich WR regions. Approximately half of the WR regions also show broad CIV emission attributed to WR stars of the WC subtype (...). The WR regions show quite clear trends between their observed WR features and the Hbeta emission line. Detailed synthesis models are presented to understand/interpret these observations. (...) The availability of a fairly large sample of metal-rich WR regions allows us to improve existing estimates of the upper mass cut-off of the IMF in a robust way and independently of detailed modeling: from the observed maximum Hbeta equivalent width of the WR regions we derive a LOWER LIMIT for M_up of 60-90 Msun in the case of a Salpeter slope and larger values for steeper IMF slopes. From our direct probe of the massive star content we conclude that there is at present no evidence for systematic variations of the upper mass cut-off of the IMF in metal-rich environments, in contrast to some claims based on indirect nebular diagnostics. (abridged abstract

Testing resistance of apple cultivars to Marssonina coronaria

The apple pathogen Marssonina coronaria (teleomorph: Diplocarpon mali) has recently become a significant problem in Central European organic apple production, causing dark spots on both the leaves and fruit, and early leaf fall. Field observations and resistance testing under controlled conditions indicate that there are differences in resistance to M.coronaria between cultivars. We screened 39 apple cultivars, selected from a large collection of genetic resources, for their susceptibility or resistance to M.coronaria. 1 year old saplings were artificially inoculated under semi-controlled conditions. The development of disease symptoms was observed and assessed several times over more than two months. Symptoms varied largely between cultivars, from small spots on which acervuli immediately developed to large round brown necrotic spots, often with one acervulus in the centre. Leaf fall often started in the middle of the shoot and in parallel on the lower, older leaves. Even though important differences in susceptibility were observed, no cultivar with complete resistance was identified. The observations suggest that resistance to the disease is complex, and involves a number of mechanisms

Survival of eclogite xenolith in a Cretaceous granite intruding the Central Dabieshan migmatite gneiss dome (Eastern China) and its tectonic implications.

International audienceInvestigation of an eclogite xenolith, discovered in a Cretaceous granite from the Central Domain of the Dabieshan massif in eastern China, yields new petrological insights into the high to ultrahigh-pressure metamorphism, experienced by the Qinling-Dabie orogen. Prior to inclusion as a xenolith in the granite during the Early Cretaceous, this eclogite xenolith had recorded a complex metamorphic evolution that complies with subduction and exhumation processes experienced by the continental crust of the South China Block. Well-preserved mineral parageneses substantiate the prograde and retrograde stages revealed by inclusions in porphyroblastic garnet and zoned minerals such as garnet, comphacite and amphibole in the matrix. The relatively low P/T re-equilibration during a latemetamorphic stage was textually inferred by the presence of aluminous and calcic-subcalcic amphiboles such as katophorite, edenite, taramite and pargasite as main matrix phases. According to our U/Pb, Rb/Sr and new 40Ar/39Ar geochronological results, namely 109 ± 1 and 112 ± 2 Ma plateau ages for muscovite and amphiboles, respectively, two successive but distinct cooling stages account for the thermal history of the granite–migmatite gneiss dome that forms the Central Dabieshan Domain. We argue that prior to the Cretaceous doming, the Central Dabieshan Domain experienced a tectono-metamorphic evolution similar to that observed in the high-pressure to ultra high-pressure units developed in the Southern Dabieshan Domain and Hong'an massif

Protein interface classification by evolutionary analysis

Background Distinguishing biologically relevant interfaces from lattice contacts in protein crystals is a fundamental problem in structural biology. Despite efforts towards the computational prediction of interface character, many issues are still unresolved. Results We present here a protein-protein interface classifier that relies on evolutionary data to detect the biological character of interfaces. The classifier uses a simple geometric measure, number of core residues, and two evolutionary indicators based on the sequence entropy of homolog sequences. Both aim at detecting differential selection pressure between interface core and rim or rest of surface. The core residues, defined as fully buried residues (>95% burial), appear to be fundamental determinants of biological interfaces: their number is in itself a powerful discriminator of interface character and together with the evolutionary measures it is able to clearly distinguish evolved biological contacts from crystal ones. We demonstrate that this definition of core residues leads to distinctively better results than earlier definitions from the literature. The stringent selection and quality filtering of structural and sequence data was key to the success of the method. Most importantly we demonstrate that a more conservative selection of homolog sequences - with relatively high sequence identities to the query - is able to produce a clearer signal than previous attempts. Conclusions An evolutionary approach like the one presented here is key to the advancement of the field, which so far was missing an effective method exploiting the evolutionary character of protein interfaces. Its coverage and performance will only improve over time thanks to the incessant growth of sequence databases. Currently our method reaches an accuracy of 89% in classifying interfaces of the Ponstingl 2003 datasets and it lends itself to a variety of useful applications in structural biology and bioinformatics. We made the corresponding software implementation available to the community as an easy-to-use graphical web interface at http://www.eppic-web.org.ISSN:1471-210

Carbon and nitrogen partitioning in Vitis vinifera L.: Responses to nitrogen supply and limiting irradiance

Potted Vitis vinifera L. plants were grown under controlled environmental conditions at five different levels of nitrogen (0, 1, 5, 10, 100 mM NH4NO3) in combination with two different levels of irradiance (photon flux densities: 30 and 140 µ mol · m-2 s-1 PAR) during bloom. Elevated N supply increased available N (particularly NO3-), K, Ca and Mg, and reduced P in the soil. Soil-NO3- and K were higher in the lower light regime, but NH4+ and other nutrients were not influenced by irradiance. The concentration of total N in the xylem sap increased as N supply was increased, although there was no further rise above intermediate soil-N levels. NO3- was the principal xylem solute, in particular under severe light restriction and high N availability. In the lower light regime, only traces of organic N could be detected in the xylem sap, whereas in the higher light treatment, glutamine and glutamate increased with increasing N application level. Light limitation reduced the concentrations of P, K and Mg in the xylem sap by about 50 %, but no response to N supply could be observed. There was a strong positive relationship between N availability and N concentration in all plant parts, while the effect on C content was minor and depended on the type and physiological age of the tissue. The amounts of total N per vine were not affected by the light treatments, although low-light stress increased N concentrations in the dry matter of the annual organs by 34-86 %. By contrast, low light led to a slight decrease of the C concentration in the annual plant parts. In the higher light regime, non-structural carbohydrates in the permanent parts of the vine declined as N availability increased. Under severe light restriction, however, the C reserve fraction was depleted and was not altered by N supply, indicating that reserves had been remobilized to support maintenance and growth processes, in order to guarantee survival of the vine

Bioseedling: a chain approach to the production of healthier seeds and seedlings of Lamb’s lettuce Valerianella locusta

The project BIOSEEDLING “Robust planting material from seeds to young plants - an implementation oriented chain approach” aims to find improved production procedures for vegetable seedlings of lamb’s lettuce. First, the production of lamb’s lettuce seeds of a professional seed producer was analyzed and the effect of harvest time and seed size on the germination and disease rate in the seeds was studied. Then, using seeds naturally infected by Peronospora valerianellae and Acidovorax valerianellae, several seed disinfection methods were compared: aerated steam, hot water, sodium hypochlorite, ethanol, Calcium hydroxide, and compost pellet. After testing methods for the identification of the seed pathogens and the quantification of the infection, an assessment on how the different treatments reduce the pathogens and whether they alter the seeds germination capacity was made. In a third step, substrates suppressive of the soil borne pathogens Rhizoctonia solanii and Pythium ultimum were developed and several plant protection agents were tested against Peronospora valerianellae. Furthermore, the effect of night interruption on the sporulation of lamb’s lettuce downy mildew (Peronospora valerianellae) using periods of lighting in the red and blue regions was tested. The aim is to combine the best methods resulting from all the experiments cited above in a future experiment and compare them to the standard methods in an on-farm experiment