Isolation,Structure Elucidation and Total Synthesis of Lajollamide A from the Marine Fungus Asteromyces cruciatus

The marine-derived filamentous fungus Asteromyces cruciatus 763, obtained off the coast of La Jolla, San Diego, USA, yielded the new pentapeptide lajollamide A (1), along with the known compounds regiolone (2), hyalodendrin (3), gliovictin (4), ¹N-norgliovicitin (5), and bis-N-norgliovictin (6). The planar structure of lajollamide A (1) was determined by Nuclear Magnetic Resonance (NMR) spectroscopy in combination with mass spectrometry. The absolute configuration of lajollamide A (1) was unambiguously solved by total synthesis which provided three additional diastereomers of 1 and also revealed that an unexpected acid-mediated partial racemization (2:1) of the L-leucine and L-N-Me-leucine residues occurred during the chemical degradation process. The biological activities of the isolated metabolites, in particular their antimicrobial properties, were investigated in a series of assay systems.     

Genetic variability,heritability and correlation among agronomic and disease resistance traits in a diversity panel and elite breeding material of spelt wheat

Spelt wheat (Triticum spelta L.) is an old‐world crop that has attracted increased attention since the 1970s accompanied by a constant increase in spelt production. Our objectives were to (i) study the genetic variability and heritability of important agronomic traits and (ii) examine the correlation among these traits for an efficient design of spelt breeding schemes. To this end, we compared a diversity panel of 150 old and new spelt varieties with current elite‐breeding material. Phenotypic data were recorded at multiple locations for yield, plant height, lodging, heading time, number of spikelets, ear snapping and susceptibility to powdery mildew, brown rust and Septoria tritici blotch. We observed highly significant genetic variances for almost all traits in both germplasm sets. Heritability estimates ranged from 0.23 for Septoria tritici blotch to 0.97 for plant height. A significant correlation between yield and plant height of ?0.56 as well as yield and lodging of ?0.39 was determined but no other correlation of yield with any of the examined traits. Thus, pedigree selection with early generation screenings on plant height and lodging can be recommended for further spelt improvement.     

Hybrid breeding for biomass yield in winter triticale: I. Hybrid performance,trait correlations and heterosis

Triticale (×Triticosecale Wittmack) holds great potential as a source for biomass production for industrial applications in Central Europe and hybrid breeding in particular appears promising owing to the higher vigour of hybrids compared to lines. In this study, a set of 178 winter triticale genotypes, including 91 hybrids, their 10 male and 23 female parental lines, as well as 54 varieties were evaluated for biomass yield and other agronomically relevant traits in 2 years at five locations in Germany. We observed a large variation of dry biomass yield as well as significant genotypic variances and high heritabilities for all traits. For the hybrids, a moderate correlation was observed between biomass and plant height and between biomass and grain yield. Mid‐parent heterosis of biomass yield ranged from ?13.6 to 16.5% with an average of 4.8%, and the maximum commercial heterosis was 9.1%. Taken together, our results illustrate the potential of hybrid breeding of triticale for biomass yield to diversify our portfolio of crops for biomass production.     

Shedding of foodborne pathogens and microbial carcass contamination of hunted wild ruminants

To assess the shedding of selected bacterial foodborne pathogens, fecal samples from 239 hunted wild red deer, roe deer, chamois, and ibex were examined. All samples tested negative for Salmonella spp. and L. monocytogenes, but other Listeria species were occasionally found. Of the 239 fecal samples, 32.6% tested positive for stx (Shiga toxins), 6.7% for eae (intimin) and 13.8% for both stx and eae genes. Among the 56 isolated Shiga toxin-producing Escherichia coli (STEC) strains, 44.6% harbored genes for the Stx2 group, 30.4% for the Stx1 group, and 21.4% for both Stx1 and Stx2. Only two of these strains harbored eae. Hence, wild ruminants constitute a reservoir for STEC, but further characterization data of the isolated strains are required to assess their actual human pathogenicity. In addition, 328 carcasses from hunted wild red deer, roe deer, and chamois were examined for total viable counts (TVC) and Enterobacteriaceae by swabbing. For the examined animal species, average TVC (4.0-4.2 log CFU cm(-2)) and average Enterobacteriaceae counts/detection rates (2.3-2.6 log CFU cm(-2); 87.5-90%) were at comparable levels. On the other hand, the microbial status of carcasses differed between certain abattoirs by several orders of magnitude. Strict compliance with good hunting and hygiene practices during any step from shooting, through evisceration in the field, to dehiding, cooling, and processing is therefore of central importance to avoid contaminations and to prevent foodborne pathogens carried by the animals from entering the food chain.     

Seed bank development after the restoration of alluvial grassland via transfer of seed-containing plant material

In the attempt to ensure long-term-conservation of flood meadows along the northern Upper Rhine transfer of seed-containing plant material was successfully applied since 2000. In this highly dynamic habitat, many typical plant species rely on a persistent seed bank for re-establishment after disturbance. But in contrast to the re-established above ground vegetation, seed bank composition remains unknown. Thus the main aims of the study were to elucidate the current seed bank composition and to assess patterns of seed and species traits. To this end we sampled above ground vegetation and seed bank on plant material plots and on control plots left to natural recruitment.Although the seed bank was still dominated by agrestal and ruderal plant species, it already contained seeds of transferred species. Analyses revealed that on the plant material plots seed density of plant material species declined significantly with soil depth, just as similarity between above ground vegetation and seed bank declined. In contrast, the seed bank on control plots comprised significantly lower numbers of transferred species. We found a vertical pattern of seed bank composition: in general, the upper seed bank layer comprised more elongated and large seeds of long-lived, competitive species able to build up transient seed bank. The lower soil layer was dominated by seeds of short-lived, agrestal and ruderal species, producing small, round and long-term persistent seeds.The present study shows that the build up of a seed bank typical of flood meadows is a time-consuming process. Thus restorative management in the early phase of vegetation development should focus on fostering high seed production of transferred species.     

Effect of elevated CO2 on soil N dynamics in a temperate grassland soil

The response of terrestrial ecosystems to elevated atmospheric CO₂ is related to the availability of other nutrients and in particular to nitrogen (N). Here we present results on soil N transformation dynamics from a N-limited temperate grassland that had been under Free Air CO₂ Enrichment (FACE) for six years. A ¹⁵N labelling laboratory study (i.e. in absence of plant N uptake) was carried out to identify the effect of elevated CO₂ on gross soil N transformations. The simultaneous gross N transformation rates in the soil were analyzed with a ¹⁵N tracing model which considered mineralization of two soil organic matter (SOM) pools, included nitrification from NH₄⁺ and from organic-N to NO₃⁻ and analysed the rate of dissimilatory NO₃⁻ reduction to NH₄⁺ (DNRA). Results indicate that the mineralization of labile organic-N became more important under elevated CO₂. At the same time the gross rate of NH₄⁺ immobilization increased by 20%, while NH₄⁺ oxidation to NO₃⁻ was reduced by 25% under elevated CO₂. The NO₃⁻ dynamics under elevated CO₂ were characterized by a 52% increase in NO₃⁻ immobilization and a 141% increase in the DNRA rate, while NO₃⁻ production via heterotrophic nitrification was reduced to almost zero. The increased turnover of the NH₄⁺ pool, combined with the increased DNRA rate provided an indication that the available N in the grassland soil may gradually shift towards NH₄⁺ under elevated CO₂. The advantage of such a shift is that NH₄⁺ is less prone to N losses, which may increase the N retention and N use efficiency in the grassland ecosystem under elevated CO₂.     

Association mapping in rice: basic concepts and perspectives for molecular breeding

In the last decade, association mapping (AM) has become a well-established method to detect genes and quantitative trait loci (QTLs) associated with agronomically important traits. The identification of a large number of single nucleotide polymorphisms (SNPs) from genome sequencing and concurrent development of high-throughput genotyping platforms has led to AM being widely used for a range of crops. These technologies have been used in rice (Oryza sativa) to explore the abundant diversity and there is enormous potential to identify novel QTLs for traits of interest. Due to the availability of cost-effective high-throughput SNP genotyping methods and rapid developments in rice genomics, it is inevitable that these AM approaches will become more popular in the future, especially in the context of genome-wide association studies (GWASs). In this paper, we review the fundamental concepts, critical considerations and limitations of AM focusing on rice, and reiterate the importance of accurate phenotypic data. We also include a section about connecting GWAS to molecular breeding, covering practical consideration for breeders, which is required to use GWAS results in actual rice molecular breeding programs and which has not received adequate attention in the scientific literature.     

The forest as a taskscape: seeing through the good forest owner’s eyes

This article is a reanalysis of interviews conducted in 2006 and 2009 with forest owners and their families. It gives a complementary interpretation of the forest owners’ decisions to replant spruce despite strong criticism from the public and from experts. The interviewees’ visual conception of the forest landscape and how they relate to it through their forestry practices is analysed. The results show that the forest owners prefer landscapes that are clean and tidy, showing characteristics indicative of forestry skills. At the same time they remain sensitive to the existence of other value systems among the public. The forest owners’ way of looking at the forest was characterized by the fact that they worked with the landscape; for them the forest is not only a symbolic project linked to identity, but also a taskscape, an imprint of performed work. In the discussion, the forest owners’ aesthetic value system is discussed and a supplementary answer is given to why forest owners refused to heed warnings about the replanting of spruce, a question that earlier studies generally attributed to forest owners’ wish to avoid short-term economic risks.