Seed conservation in ex situ genebanks - genetic studies on longevity in barley

Recognizing the danger due to a permanent risk of loss of the genetic variability of cultivated plants and their wild relatives in response to changing environmental conditions and cultural practices, plant ex situ genebank collections were created since the beginning of the last century. World-wide more than 6 million accessions have been accumulated of which more than 90% are stored as seeds. Research on seed longevity was performed in barley maintained for up to 34 years in the seed store of the German ex situ genebank of the Leibniz-Institute of Plant Genetics and Crop Plant Research in Gatersleben. A high intraspecific variation was detected in those natural aged accessions. In addition three doubled haploid barley mapping populations being artificial aged were investigated to study the inheritance of seed longevity. Quantitative trait locus (QTL) mapping was based on a transcript map. Major QTLs were identified on chromosomes 2H, 5H (two) and 7H explaining a phenotypic variation of up to 54%. A sequence homology search was performed to derive the putative function of the genes linked to the QTLs

A population-based survey on tanning bed use in Germany

<p>Abstract</p> <p>Background</p> <p>The suntanning industry has grown up over the last decade in Europe, mainly because tanned skin is considered socially desirable and attractive. Because of the potential negative impact of artificial tanning on public health, this study was to investigate tanning bed use behaviour, UV related risk perception and beliefs about tanning in the German population.</p> <p>Methods</p> <p>In 2007, a representative telephone survey was carried out among 1501 German residents aged 14 years and older.</p> <p>Results</p> <p>More than one fourth (28%) of the German population have used tanning beds at least once before in their lifetime. High-frequency tanning behaviour, i.e. using tanning beds more than 10 times per year, were recorded for 11%. Men and women aged 18 to 44 years and young women under the age of 18 used tanning beds more frequently (>10 times per year). Tanning bed use was positively related to appearance and lifestyle related beliefs as well as to the perception that tanned skin is healthy.</p> <p>Conclusion</p> <p>This analysis indicates that tanning bed use is common in Germany. The positive relationships of appearance and health related beliefs with tanning bed use are of great concern. The results indicate underlying misconceptions about the positive effect of artificial UV radiation compared to natural UV radiation particular for high-frequency tanners. The data shows the importance as well as the limitations for risk communication in its current effort to inform effectively about the dangers of artificial UV radiation.</p

Variability of alkaloid content in Papaver somniferum L.

A total of 300 accessions of opium poppy (Papaver somniferum L., Papaveraceae) of the IPK genebank collection from nearly all over the world were cultivated under field conditions in Gatersleben for morphological and phytochemical characterisation. Altogether 35 morphological and agronomic characters were collected for all accessions. Determination of chromosome numbers with flow cytometry showed that the accessions of subspecies setigerum are tetraploid whereas all accessions of the other subspecies are diploid. Composition and content of the five main alkaloids (morphine, codeine, thebaine, papaverine and noscapine) were analysed by high performance liquid chromatography (HPLC). Total alkaloid content varied between 683.32 and 25,034.84 μg/g dry matter (first year) and 1,799.49 and 25,338.55 μg/g dry matter in the second year of cultivation. There is a highly significant correlation between total content of alkaloids and morphine in both years (r=0.926/P=0.000; r=0.918/P=0.000). In contrast, the other four main alkaloids show less or no correlation with each other or the total alkaloid content. This analysis demonstrated that the amount and composition of the main alkaloids are highly variable. Additionally, there is no important correlation between morphological characters and alkaloid content. So it is not possible to use these characters as a prediction tool of alkaloid content during breeding process

Uncovering the genetic architecture of spike related traits in bread wheat: a viable alternative to increase yield potential

Non-Peer ReviewedBased on the projected demand, further improvements in wheat grain yield are required. In this sense, exploring the genetic diversity associated with yield related traits is critical to derive superior progenies from crossing and selection. However, the possible presence of trade-off between traits must be considered to determine their relevance for improving yield potential. In this study, we determined the phenotypic and genetic relationships between twelve spike related traits and their genetic basis through an association mapping study using a 15K Infinium SNP array, characterized in a bread wheat panel. To identify potential candidate genes, regions of interest were positioned onto the newly released wheat reference genome sequence by blasting their peaking marker sequences against the IWGSC RefSeq v1.0. From all the analyzed traits, grain number per fertile spikelet (GFS) showed the highest correlation with grain number per spike (GNS), whereas there was no relationship with thousand kernel weight (TKW). As a result, significant increases in grain weight per spike (GWS) associated with higher GFS was observed. Interestingly, GFS was mostly explained by spikelet weight (SW), indicating that improvements in yield potential could be achieved through partition improving within the spike. In addition, the genetic analysis showed independent genetic control between GFS and both, GNS and TKW, suggesting the potential value of GFS as selection criterion to increase yield potential in wheat breeding programs. A total of 54 significant marker-trait associations were detected for spike related traits, including two genomic regions on 1B and 7A linked to GFS and 6 genomic regions located on 1A, 1B, 2B, 3A, 5A and 7B associated to SW. The potential candidate genes for these regions included several sugar transporter and carbohydrate-binding protein. The markers linked to GFS and SW are really promising, especially considering that due to the destructive phenotypic determination, their improvement in early breeding generations can only be made by marker-assisted selection

Deterministic and stochastic influence of nutrients on phytoplankton function and structure in coastal waters

Knowledge of how phytoplankton responds to nutrient inputs is essential for water management and for minimizing eutrophication. Only processes that are deterministic, i.e. that can respond as algorithms, are controllable. The study area is the chain of inshore waters (so-called Bodden) south of the Darss-Zingst peninsula - shallow eutrophic waters of estuarine character in the Southern Baltic. Monitoring programmes and laboratory experiments have revealed an annual periodicity of the phytoplankton and of the physico-chemical factors influencing it. On the basis of these results, experiments were carried out in enclosures to study the effects of nutrient loading on phytoplankton. The purpose was to test the feasibility of influencing phytoplankton development under field conditions during the transition period from late spring to mid-summer. This contribution presents results from the 1985 shallow water enclosure experiments (FLAK 85) which demonstrate that - the scale of phytoplankton reactions and the species involved are stochastic in character and are governed by stochastic interactions between meteorological events and water exchange processes in the chain of Bodden; - all processes affecting phytoplankton growth are deterministic in character, conforming to simple batch theories: simultaneous addition of nitrogen and phosphorus favours green algae, and in exceptional cases one algal species became dominant; - nutrient loadings do not affect the time of transition to the mid-summer phytoplankton population, the most important regulating factor obviously being temperature

Priority areas for watershed service conservation in the Guapi-Macacu region of Rio de Janeiro, Atlantic Forest, Brazil.

Introduction: Land use intensification and urbanisation processes are degrading hydrological ecosystem services in the Guapi-Macacu watershed of Rio de Janeiro. A proposal to pay farmers to restore natural watershed services might be an alternative to securing the water supply in the long-term for the around 2.5 million urban water users in the study region. This study quantifies the costs of changing current land use patterns to enhance watershed services and compares these costs to the avoided costs associated with water treatment for public supply. Methods: We use farm-household data to estimate the opportunity costs of abandoning current land uses for the recovery of natural vegetation; a process that is very likely to improve water quality in terms of turbidity due to reduced inputs from erosion. Opportunity cost estimates are extrapolated to the watershed scale based on remote sensing land use classifications and vulnerability analysis to identify priority zones for watershed management interventions. To assess the potential demand for watershed services, we analyse water quality and treatment cost data from the main local water treatment plant. Results: Changing agricultural land uses for watershed services provision generally comes at high opportunity costs in our study area near to the metropolis of Rio de Janeiro. Alternative low cost watershed conservation options do exist in the livestock production sector. These options have the potential to directly reduce the amount of sediments and nutrients reaching the water bodies, and in turn decrease the costs of treatment needed for drinking water. Land cover changes at the scale needed to improve water quality will, nonetheless, likely exceed the cost of additional investments in water treatment. Conclusions: The state water utility company?s willingness to pay for watershed services alone will not be enough to induce provision of additional watershed services. We conclude that monetary incentives conditioned on specific adjustments to existing production systems could still have a complementary role to play in improving watershed services. However, we note that our willingness to pay analysis focusses on only one of the potentially wide range of ecosystem services provided by natural vegetation in the Guapi-Macacu watershed. Factoring these ecosystem services into the willingness to pay equation is likely to change our assessment in favour of additional conservation action, be it through PES or other policy instruments

QTLs for salt tolerance in three different barley mapping populations 2006

Soil salinity is one of the crucial factors limiting crop production. Progression of salinisation of agriculturally arable land is mainly connected with mismanagement of water in irrigation systems, in particular under arid and semiarid climate conditions and global changes of water flow in the landscape. Selection of salt tolerant genotypes is necessary to ensure yield and to reclaim salt affected soils. The development of molecular marker(s) could facilitate the selection process. Phenotyping of mapping populations under salt stress conditions and calculation of QTLs are suitable instruments to detect markers that are responsible for tolerance/sensitivity. However, a quantitative inherited trait like salt tolerance requires a range of adaptations, with a whole host of genes interacting with each other to produce the visible phenotype

T160‐phosphorylated CDK2 defines threshold for HGF‐dependent proliferation in primary hepatocytes

Liver regeneration is a tightly controlled process mainly achieved by proliferation of usually quiescent hepatocytes. The specific molecular mechanisms ensuring cell division only in response to proliferative signals such as hepatocyte growth factor (HGF) are not fully understood. Here, we combined quantitative time-resolved analysis of primary mouse hepatocyte proliferation at the single cell and at the population level with mathematical modeling. We showed that numerous G1/S transition components are activated upon hepatocyte isolation whereas DNA replication only occurs upon additional HGF stimulation. In response to HGF, Cyclin:CDK complex formation was increased, p21 rather than p27 was regulated, and Rb expression was enhanced. Quantification of protein levels at the restriction point showed an excess of CDK2 over CDK4 and limiting amounts of the transcription factor E2F-1. Analysis with our mathematical model revealed that T160 phosphorylation of CDK2 correlated best with growth factor-dependent proliferation, which we validated experimentally on both the population and the single cell level. In conclusion, we identified CDK2 phosphorylation as a gate-keeping mechanism to maintain hepatocyte quiescence in the absence of HGF