Genetic diversity in the top onion,Allium ×proliferum (Alliaceae), analysed by isozymes

Polymorphisms for six enzyme systems (GPI, IDH, PDG, PGM, SKD, and TPI) were analysed in the top onion,Allium ×proliferum. Five multilocus isozyme genotypes were found. The banding patterns of top onions were compared with those ofA. ×wakegi, A. cepa, A. fistulosum, A. altaicum, and artificial hybrids between these three species. One top onion type and one artificial hybrid had identical banding patterns. Shallots andA. altaicum, the wild progenitor ofA. fistulosum, cannot be distinguished from the common onion andA. fistulosum, respectively; these species are also potential contributors to the top onion's gene pool.     

Phytochemical analysis of alkaloids from the Icelandic club moss Diphasiastrum alpinum

8S-O-acetylepiclavolonine, a new Lycopodium alkaloid, was isolated from the Icelandic club moss Diphasiastrum alpinum and its structure and stereochemistry was determined using a combination of NMR spectroscopy and mass spectrometry. The previously described alkaloids 5R,8R-O-acetylfawcettiine, 5R,8S-O-acetyllofoline, lycodoline and anhydrolycodoline were found in D. alpinum for the first time together with previously reported lycopodine and clavolonine. The ¹H NMR spectra of 8S-O-acetylepiclavolonine and 5R,8S-O-acetyllofoline, revealed a highly deshielded proton at ca. 12 ppm, which seems to be stabilized by an intramolecular hydrogen bond to the carbonyl oxygen of the 8S-O-acetyl group. The isolated alkaloids were tested toward acetylcholinesterase in vitro without showing significant inhibition.     

The impact of herbivore exclusion on forb diversity: Comparing species and functional responses during a drought

Rainfall and herbivory shape savannah herbaceous communities, but these disturbances are being altered globally. To assess potential consequences of such alterations, we evaluated herbivore effects on species and functional diversity during an episodic drought in a sodic savannah using data collected from long-term herbivore exclosures in the Kruger National Park, South Africa. Herbaceous life forms are rarely acknowledged as distinct functional entities. Moreover, the functional ecology of forbs remains elusive. Here, we present disturbances–responses by forbs separately from grasses. We hypothesised that combinations of intense utilisation and drought would be associated with low diversity and high dominance at species and functional levels for both life forms. Contrary to our hypothesis, low forb and grass diversity was associated with long-term herbivore exclusion, which exceeded expected undesirable effects of intense utilisation and drought. Grasses responded less sensitively, suggesting that forbs respond dynamically to changes in herbivore assemblage when these alterations are combined with drought. Consistent with patterns in savannah systems, forbs contributed significantly to species and functional trait diversity. High forb diversity is suggested to enhance resilience of this nutrient-rich ecosystem against declines in its functioning when subjected to drought and alterations in herbivory.     

The Association of Plasma Cysteine and γ‐Glutamyltransferase With BMI and Obesity

We recently reported a strong positive association of plasma total cysteine (tCys) with fat mass in over 5,000 subjects. As γ‐glutamyltransferase (GGT) enzyme increases cysteine availability by catalyzing glutathione breakdown and is positively associated with BMI and adiposity, we hypothesized that GGT might explain the association of tCys with adiposity. To study whether the associations of tCys and serum GGT with BMI and obesity were interrelated we conducted a cross‐sectional study using data from 1,550 subjects recruited from nine European countries in the COMAC project. Multiple linear and logistic regression models and concentration‐response curves were used. In age and sex‐adjusted analyses, tCys showed strong positive associations with BMI (partial r = 0.19, P < 0.001), and obesity (odds ratio (OR) for 4th vs. 1st tCys quartile: 2.8; 95% confidence interval: 1.6–5.0, P < 0.001), both of which remained robust after adjustment for GGT and other metabolic and lifestyle confounders. Serum GGT was also a positive predictor of BMI (partial r = 0.17, P < 0.001) and obesity (OR for 4th vs. 1st GGT quartile: 4.8; 95% confidence interval: 2.5–9.2, P < 0.001), independent of tCys. However, the associations of GGT with BMI and obesity were weakened by adjustment for obesity‐related factors such as serum lipids and blood pressure. These results indicate that tCys is a strong positive predictor of BMI and obesity, independent of GGT and other obesity‐related factors. We also suggest that the association of serum GGT with BMI and obesity is unrelated to the role of GGT in cysteine turnover. The potential link between cysteine and fat metabolism should be further evaluated.     

Equivalence of citizen science and scientific data for modelling species distribution of birds from a tropical savanna

The Wallacean deficit continues to be a challenge to species distribution modelling. Although some authors have suggested that data collected by citizen scientists can be relevant for a better understanding of biodiversity, to our knowledge, no work has quantitatively tested the equivalence between scientific and citizen science data. Here, we investigate the hypothesis that data collected by citizen scientists can be equivalent to data collected by professional scientists when generating species spatial distribution models. For 42 bird species in the Cerrado region we generated and compared species distribution models based on three data sources: (1) scientific data, (2) citizen science data and (3) sample size corrected citizen science data. To test our hypothesis, we compared the equivalence of these datasets. We rejected the hypothesis of equivalence for about one-third (38%) of the evaluated species, revealing that, for most of the species considered, the models generated were equivalent irrespective of the data set used. The distances between centroids of the models that were equivalent were on average smaller than the distances between non-equivalent models. Also, the direction of change in the models showed no pattern, with no trend towards more populated regions. Our results show that the use of data collected by citizen scientists can be an ally in filling the Wallacean deficit gap. In fact, the lack of use of this wide range of data collected by citizen scientists seems to be an unjustified caution. We indicate the potential of using citizen science data for modelling the distribution of species, mainly due to the large set of data collected, which is impracticable for scientists alone to collect. Conservation measures will be favoured by the union of professional and amateur data, aiming for a better understanding of species distribution and, consequently, biodiversity conservation.