Reversing agriculture from intensive to sustainable improves soil quality in a semiarid South Italian soil

Intensive agriculture (IA) is widespread in South Italy, although it requires frequent tillage, large amounts of fertilizers and irrigation water. We have assessed the efficacy of reversing IA to sustainable agriculture (SA) in recovering quality of a typical South Italy soil (Lithic Haploxeralf). This reversion, lasting from 2000 to 2007, replaced 75% of nutrients formerly supplied inorganically by farmyard manuring and reduced the tillage frequency. Several chemical and biochemical properties, functionally related to C and N mineralisation–immobilisation processes and to P and S nutrient cycles, were monitored annually from 2005 to 2007 in the spring. Reversing IA to SA decreased soil bulk density, almost doubled the soil organic matter (SOM) as favoured the immobilisation of C and N, increased most soil microbial indicators but decreased contents of nitrate, mineral N and K₂SO₄-extractable C. The K₂SO₄-extractable C/K₂SO₄-extractable organic N ratio suggested that substrate quality rather than the mass of readily available C and N affected biomass and activity of soil microflora. Also, the largely higher 10-day-evolved CO₂–C-to-inorganic N ratio under SA than IA indicated that higher C mineralisation, associated with higher microbial biomass N immobilisation, occurred under SA than IA. Decreases in most soil enzyme activities under IA, compared to SA, were much higher than concomitant decreases in SOM content. Soil salinity and sodicity were always higher in IA than SA soil, although not critically high, likely due to the intensive inorganic fertilisation as irrigation waters were qualitatively and quantitatively the same between the two soils. Thus, we suggest that the cumulative small but long-term saline (osmotic) and sodic (dispersing) effects in IA soil decreased the microbial variables more than total organic C and increased soil bulk density.     

Proton transfer reaction-mass spectrometry (PTR-MS) headspace analysis for rapid detection of oxidative alteration of olive oil

Olive oil has been characterized by rapid proton transfer reaction-mass spectrometry (PTR-MS) headspace analysis without any concentration of the volatiles or pretreatment of the samples. Comparison of extra virgin and defective (rancid) samples, as described by a panel of sensory judges, and the monitoring of thermo-oxidation processes are discussed. Multivariate analysis of PTR-MS data has been carried out and cross-validated, providing (i) reliable classification models for extra virgin oil as opposed to defective oil and (ii) calibration models able to predict independently thermo-oxidative degradation and the corresponding peroxide value. PTR-MS fragmentation patterns of volatiles considered in this study are also reported.     

Comparative analysis of the effects of locally used herbicides and their active ingredients on a wild-type wine Saccharomyces cerevisiae strain

Herbicides are released to the environment with potential ecotoxicological risks for mammals. Yeast is a good model to elucidate toxicity mechanisms. We investigated how three commercial herbicides (Proper Energy, Pointer, and Silglif) and their active ingredients (respectively, fenoxaprop-P-ethyl, tribenuron methyl, and glyphosate) can affect biological activities of an oenological Saccharomyces cerevisiae strain, which may be resident on grape vineyards of the same geographical areas where herbicides are used. The use of commercial grade herbicides employed in Italy allowed us to reproduce the same conditions applied in crops; at the same time, assaying pure single active compounds made it possible to compare the effects obtained with commercial formulations. Interestingly, we found that while pure active compounds affect cell growth and metabolism at a lower extent, commercial preparations have a significant major negative influence on yeast biology.     

Evolution of minor polar compounds and antioxidant capacity during storage of bottled extra virgin olive oil

We characterized "Olivastra Seggianese" extra virgin olive oil (EVOO) and evaluated its chemical and sensory characteristics and antioxidant and antiradical activities during storage under novel conditions. Two oils (A and B) were analyzed for the commodity characteristics at blending (t0) and after 9, 12, and 18 months; panel tests were performed and minor polar compounds (MPC) content was assessed at blending (t0) and after 6, 9, 12, and 18 months. Antioxidant and antiradical activities in vitro were evaluated at t0 and after 12 months, by human low density lipoprotein (LDL) and 1,1-diphenyl-2-picrylhydrazil radical (DPPH*) tests. Oil A, which had an initially higher MPC content, possessed "harder" organoleptic characteristics than oil B, which had a lower MPC content and was endowed with a "smoother" taste profile. Statistical analyses showed that secoiridoids, particularly deacetoxy-oleuropein aglycone, should be quantified to evaluate EVOO stability during storage. The antioxidant activity toward human LDL was linked to MPC content and to storage time. The tests on the stable free radical DPPH* confirmed the results on human LDL. We propose this as an additional parameter to evaluate olive oil quality and stability over time.     

QTL mapping for the cooking time of common beans

The decrease in the per capita consumption of beans has been partially attributed to their lengthy cooking time and the aggregated capital costs of their preparation. The aim of this study was to map microsatellite (SSR) markers linked to quantitative trait loci (QTLs) that govern the cooking time of common beans. An F₂ generation consisting of 140 families was generated from a cross between lines CNFM7875 and Laranja. The cooking time of the F_2:4 and F_2:5 generations was then evaluated, and the latter generation was tested in two environments. The analysis of variance found a significant effect for the interactions between the families (P < 0.01) in both the F_2:4 and F_2:5 generations, as well as for the group analyses performed in the two environments. The experimental coefficient of variation varied from 9.42 to 17.94%. The Pearson’s correlation test indicated no significant association between water absorption and cooking time. The heritability coefficients had values of 0.532 and 0.739 for the F_2:5 families evaluated at the two different locations, and the group analysis of the F_2:5 generation indicated that there was a significant genotype × environment interaction. Of the 105 polymorphic SSRs evaluated, 91 mapped to 12 linkage groups with an estimated map size of 1,303.7 cM. Six significant QTLs were detected in both environments, and the percentage of the phenotypic variation that was explained by these loci ranged from 11.54 to 21.63%. As the genetic control was oligogenic, the identification of QTLs should serve as an optimal starting point for the implementation of a selection program.     

An abundance of rare functional variants in 202 drug target genes sequenced in 14,002 people

Rare genetic variants contribute to complex disease risk; however, the abundance of rare variants in human populations remains unknown. We explored this spectrum of variation by sequencing 202 genes encoding drug targets in 14,002 individuals. We find rare variants are abundant (1 every 17 bases) and geographically localized, so that even with large sample sizes, rare variant catalogs will be largely incomplete. We used the observed patterns of variation to estimate population growth parameters, the proportion of variants in a given frequency class that are putatively deleterious, and mutation rates for each gene. We conclude that because of rapid population growth and weak purifying selection, human populations harbor an abundance of rare variants, many of which are deleterious and have relevance to understanding disease risk.     

Behaviour of metolachlor and terbuthylazine in cultivated field lysimeters

An experiment has been carried out in cultivated drainage lysimeters filled with reported soil in order to investigate on the disappearance and mobility of Metolachlor and Terbuthylazine as related to the nitrogen fertilization level. Two experimental units have been compared: in the O-N treatment the soil did not receive N fertilizers during the 7 years previous to the experiment, whereas in the H—N treatment the average application rate of nitrogen during the same period was 220 kg ha^?1 year^?1; a corn crop has been cultivated in the present experiment. The active ingredients have been analysed in the artificial soil profile (from 0 to 40 cm, by 10 cm soil layers) and in leachates. The disappearance rate of Terbuthylazine was affected by nitrogen fertilization level, as the half life resulted about 7 days higher in O—N (21.9 days) treatment than in H—N (14.6 days). On the contrary, N fertilization did not significantly modify the half life of Metolachlor (17.2 and 15.9 days at O—N and H—N, respectively). A N-dealkylated degradation product of Terbuthylazine has been found in the shallow soil layers. The distribution pattern of herbicides content in the soil profile showed that Terbuthylazine was less mobile than Metolachlor. Leachates did not contain Terbuthylazine at all, but amounts of Metolachlor close to the detection limits (25 μg L^?1).