Long‐Term Durum Wheat‐Based Cropping Systems Result in the Rapid Saturation of Soil Carbon in the Mediterranean Semi‐arid Environment

Climate, soil physical–chemical characteristics, land management, and carbon (C) input from crop residues greatly affect soil organic carbon (SOC) sequestration. According to the concept of SOC saturation, the ability of SOC to increase with C input decreases as SOC increases and approaches a SOC saturation level. In a 12‐year experiment, six semi‐arid cropping systems characterized by different rates of C input to soil were compared for ability to sequester SOC, SOC saturation level, and the time necessary to reach the SOC saturation level. SOC stocks, soil aggregate sizes, and C inputs were measured in durum wheat monocropping with (Ws) and without (W) return of aboveground residue to the soil and in the following cropping systems without return of aboveground residue to soil: durum wheat/fallow (Wfall), durum wheat/berseem clover, durum wheat/barley/faba bean, and durum wheat/Hedysarum coronarium. The C sequestration rate and SOC content were lowest in Wfall plots but did not differ among the other cropping systems. The C sequestration rate ranged from 0.47 Mg C ha⁻¹ y⁻¹ in Ws plots to 0.66 Mg C ha⁻¹ y⁻¹ in W plots but was negative (−0.06 Mg C ha⁻¹ y⁻¹) in Wfall plots. Increases in SOC were related to C input up to a SOC saturation value; over this value, further C inputs did not lead to SOC increase. Across all cropping systems, the C saturation value for the experimental soil was 57.7 Mg ha⁻¹, which was reached with a cumulative C input of 15 Mg ha⁻¹. Copyright © 2015 John Wiley & Sons, Ltd.     

Molecular and physico-chemical evaluation of enzymatic browning of whole meal and dough in a collection of tetraploid wheats

Many studies have demonstrated the role of polyphenol oxidase (PPO; E.C. 1.14.18.1) in darkening of wheat products. Even slight browning of pasta is a major hindrance to consumer acceptance. The aim of this research was to evaluate the variability of PPO activity, browning level, and protein content in a collection of more than 100 genotypes of tetraploid wheat, including cultivars and landraces. A molecular approach was followed to evaluate the efficiency of marker PPO18, discovered and used in common wheat, in detecting tetraploid wheat genotypes with low browning level. The data showed a significant genotype influence on the activity of the PPO enzyme, which was correlated with brown index of whole meal and dough, and with protein content. On the whole, the cultivars showed lower PPO activity, brown index, and protein content than landraces, but wide variability was present. Marker PPO18 detected four different alleles for Ppo-A1. The allele Ppo-A1f identified genotypes with high PPO activity and brown index, while the Ppo-A1b and null alleles were associated with the opposite characteristics. Hence, this marker can be used to select new tetraploid wheat cultivars with low browning level.     

Quantitative trait loci for yellow pigment concentration and individual carotenoid compounds in durum wheat

A defining factor for the commercial value of durum wheat pasta is its amber colour, which depends on the semolina yellow pigment concentration and on the oxidative enzymatic activity. Among carotenoids controlling yellow colour, the presence of β-carotene is also important as precursors of vitamin A. The aim of the present study was to detect quantitative trait loci (QTL) for yellow pigment concentration, yellow index and individual carotenoid compounds (lutein, zeaxanthin, β-cryptoxanthin, α-carotene and β-carotene) in a durum segregant population. Total carotenoid concentration amounted to 37% of the yellow pigments, indicating unknown colour-producing compounds in the durum extracts. Lutein was the most abundant carotenoid, followed by zeaxanthin, α-carotene and β-carotene, while β-cryptoxanthin was a minor component. Phytoene synthase marker Psy-A1, 150 SSR and EST-SSR markers, and 345 DArT^® markers, were used to construct the linkage map for subsequent QTL analysis. Clusters of QTL for total and/or one or more carotenoid compounds were detected on the same chromosome regions (2A, 3B, 5A and 7A) where QTL for yellow pigment concentration and yellow index were identified. The molecular markers associated to major QTL would be useful for marker-assisted selection programs to facilitate high carotenoid concentration with high nutritional carotenoid compounds in wheat grain.     

Optimum use of milk in traditionally managed cattle herds in the tropics

In traditional cattle systems in the tropics, the milk produced is generally shared between the calf and the cattle keeper. This literature review evaluates the socio-economic aspects related to milk production and milk use in traditional cattle systems and identifies the best strategies of milk allocation in order to improve food security and maximise income. The available literature indicates that milk, in terms of economic, social and subsistence value, is more valuable than meat. Thus, under the conditions that characterise traditional cattle systems in the tropics, it is appropriate to have a higher milk offtake at the expense of calf growth. This review also found that certain management practices, such as restricted suckling, can be useful to minimise mortality of calves, while improving milk offtake for human consumption.     

CERCOPRI: a forecasting model for primary infections of cercospora leaf spot of sugarbeet1

A computerized model for forecasting the appearance of primary infections of cercospora disease on sugarbeet was worked out using meteorological and epidemiological data collected in the western Po Valley from 1980 to 1989. This program, called CERCOPRI, gives a figure for the current risk of disease appearance, a forecast of the risk on a pre-established day or a forecast of the day on which risk will reach a pre-established threshold.     

Chlorophyll a fluorescence analysis along a vertical gradient of the crown in a poplar (Oxford clone) subjected to ozone and water stress

An experiment in open-top chambers was carried out in summer 2008 at Curno (Northern Italy) in order to study the effects of ozone and mild water stress on poplar cuttings (Oxford clone). In this experiment direct fluorescence parameters (JIP-test) were measured in leaves from different sections of the crown (L: lower; M: medium; U: upper parts of the crown). The parameters considered were calculated at the different steps of the fluorescence transient, and include maximum quantum yield efficiency in the dark-adapted state (F(v)/F(M)); the L-band, at 100?∝?s, that expresses the stability of the tripartite system reaction centre-harvesting light complex-core antenna; the K-band, at 300?∝?s, that expresses the efficiency of the oxygen-evolving complex; the J-phase, at 2 ms, that expresses the efficiency with which a trapped exciton can move an electron into the electron transport chain from Q(A)(-) to the intersystem electron acceptors; the IP-phase, which expresses the efficiency of electron transport around the photosystem 1 (PSI) to reduce the final acceptors of the electron transport chain, i.e., ferredoxin and NADP; and finally the performance index total (PItot) for energy conservation from photons absorbed by PSII to the reduction flux of PSI end acceptors. The main results are: (i) different dynamics were observed between leaves in the lower section, whose PItot decreased over time, and those in the upper sections in which it increased, with a dynamic connected to the leaf age; (ii) ozone depressed all the considered fluorescence parameters in basal leaves of well-watered plants, while it had little or no damaging effect on medium-level or upper-section leaves; (iii) PItot and IP-phase increased in upper leaves of plants subjected to ozone stress, as well as the net photosynthesis; (iv) water stress increased PItot of leaves in all levels of the crown. The results suggest that ozone-damaged poplar plants compensate, at least partially, for the loss of photosynthesis with higher photosynthetic rates in young leaves (in the upper section of the crown), more efficient to fix carbon.     

Clinical use of a low-dose medetomidine infusion in healthy dogs undergoing ovariohysterectomy

Eight healthy dogs undergoing elective ovariohysterectomy were anesthetized with a standard protocol and received a low-dose medetomidine constant rate infusion during surgery. Cardiorespiratory parameters, including non-invasive cardiac output, were measured at various times. This protocol resulted in acceptable and stable cardiovascular performance, allowed low isoflurane concentrations, and provided smooth recoveries.