Applications of response surface methodology approach to determine the effect of temperature, time of incubation and light conditions on germination and germ tube growth of Puccinia coronata f.sp. avenae urediosopores

Crown rust caused by Puccinia coronata f.sp. avenae is the most damaging disease on oat. This work analyzed the effects of temperature and illumination regime during different time of incubation on both spore germination and germ tube growth, using both analysis of variance (ANOVA) and response surface methodology (RSM). This study reveals that the maximum of germination approached 95% under dark conditions at 20°C. Similarly, the maximum germ tube length was 125±23 μm under dark conditions at the same temperature after 18 h. Both spore germination and germ tube growth were observed over a wider temperature range of 5 to 30°C. The darkness conditions seem to enhance significantly (P < 0.05) both the germination and germ tube growth. After 4 h of incubation, germination was significantly higher under darkness regime at 15, 20 and 25°C than under light conditions. The effect of darkness conditions on germ tube growth paralleled its effect on germination. Furthermore, the response surface methodology (RSM) was applied to determine the optimal conditions of temperature, time and illuminations conditions for both the germination process and germ tube growth of urediospores for P. coronata f.sp. coronata. Values for the optimal germination and germ tube growth were 20°C and 8 h under darkness conditions. Moreover, urediospores of P. coronata f.sp. coronata germination and germ tube growth had followed a quadratic response function on temperature (R² = 0.94 and 0.97). On the other hand, the experimental values were in good agreement with the predicted ones and the model was highly significant with the correlation coefficient R being 0.97 and 0.98, respectively for germination and germ tube growth.Key words: Puccinia coronata f.sp. avenae, temperature, time, illuminations conditions, germination process, germ tube growth, urediospores

Morphological, physiological and pathogenic variability of small-spore Alternaria sp. causing leaf blight of Solanaceous plants in Algeria

Due to premature defoliation, early blight epidemics can cause major yield losses. Large-spore Alternaria species such as A. solani and A. tomatophila have long been recognized as important pathogens responsible for such blight disease in the family Solanaceae and thus represent a serious risk for crop production. Small-spore Alternaria species have also been frequently isolated from plant samples with typical blight symptoms but their incidence as primary pathogens is often controversial. In order to study the diversity of small-spore Alternaria species, 32 isolates were selected from a larger collection of 130 isolates from infected leaves, fruits and stems of tomato from various growing regions of North-West Algeria. Morphological characterization under standard conditions and polymerase chain reaction (PCR) analyses using specific primers to amplify a part of the ITS regions and the 5.8S gene were conducted to confirm their identification as members of the alternata section. They were then examined according to morphological characteristics of conidia and sporulation patterns on potato carrot agar (PCA) and were segregated into three morphological species: A. alternata, A. tenuissima and A. arborescens. Colony type, substrate colour, margin, zonation, pigmentation, colony diameter and conidia production were studied on potato sucrose agar (PSA). Physiological parameters and nutritional requirements of the isolates were also assessed and a data matrix based on cluster analysis and Euclidean distance was constructed. Results of pathogenicity test on tomato showed obvious diversity among the isolates and they could be separated into two groups based on their virulence. The dendrogram based on the influence of cultural, nutritional and physiological characters suggests moderate heterogeneity within the populations of A. alternata and A. tenuissima. The small-spore species formed five clusters that fundamentally paralleled the morphological groupings. However, the results provided no evidence for geographical and pathogenicity clustering of isolates

Food waste reduction in supply chains through innovations: a review

Purpose – Agri-food supply chains are facing a number of challenges, which cause inefficiencies resulting in the waste of natural and economic resources, and in negative environmental and social impacts. Food waste (FW) is a result of such inefficiencies and supply chain actors search for economically viable innovations to prevent and reduce it. This study aims to analyse the drivers and the barriers that affect the decision of supply chain operators to adopt innovations (technological – TI, organisational – OI and marketing – MI) to reduce FW. Design/methodology/approach – The analysis was carried out using a four-step approach that included: a literature review to identify factors affecting the decision to adopt innovations; analysis of FW drivers and reduction possibilities along agri-food supply chains through innovations; mapping the results of Steps 1 and 2 and deriving conclusions regarding the factors affecting the adoption of innovations to reduce and prevent FWFindings Results show that different types of innovations have a high potential in reducing and preventing FW along the supply chain; however, they still must be economically feasible to be adopted by decision makers in the food supply chain. TI, OI and MI are often interrelated and can trigger each other. When it comes to a combination of different types of innovation to reduce and prevent FW, a good example of combining TI, OI and MI may be observed in the retail sector in Europe. Here, innovative smartphone apps (TI) to promote the sale of products nearing their expiration dates (OI in terms of organising the sales differently and MI in terms of marketing it differently) were developed and adopted via different retailing channels, leading to the creation of a new business model. Practical implications This study analyses the drivers of FW generation together with the factors affecting the decision to adopt innovations to reduce it and provides solutions to supply chain operators to prevent and reduce FW through different types of innovations. Originality/value Literature has not systematically addressed innovations aiming at the reduction of FW yet. This paper provides a comprehensive literature review of the determinants of innovation adoption and offers a novel view on the problem of FW reduction by means of innovation, by linking factors affecting the decision to innovate with FW drivers. Supply chain, Food waste, Technological innovation, Organisational innovation, Marketing innovationpublishedVersio

From social interactions to private environmental behaviours: The case of consumer food waste

Consumer food waste, like many environmental behaviours, takes place in private, and is not directly subject to social monitoring. Nevertheless, social interactions can affect private opinions and behaviours. This paper builds an agent-based model of interactions between consumers heterogeneous in their sociability, their initial opinions and behaviours related to food waste, and their willingness to consider different opinions, in order to assess how social interactions can affect private behaviours. Compared to existing models of opinion dynamics, we innovate by including a range of “cognitive dissonance” between stated opinions and actual behaviours that consumers are willing to accept before changing one of the two. We calibrate the model using questionnaire data on household food waste in Italy. We find that a limited degree of mixing between different socio-demographic groups, namely adult and young consumers, is enough to trigger change, but a certain openness of mind is required from more wasteful individuals. Equally, a small group of environmentally committed consumers can attract a sizeable share of the population towards low-waste behaviours if they show a certain variability of opinions and are willing to compromise with individuals in their close neighbourhood in terms of opinions. These findings can help design effective interventions to promote pro-environmental behaviours, taking advantage of the beneficial network effects while anticipating negative externalities

Ion Microscopy: A New Approach for Subcellular Localization of Labelled Molecules

Secondary ion mass spectroscopy (SIMS) was used to obtain images representing the intracellular distribution of molecules labelled with carbon 14. Deoxyadenosine labelled with carbon 14 was added to a cultured human fibroblast cell medium, and the intracellular distribution of this molecule was studied using three different SIMS instruments: the CAMECA IMS 3F and SMI 300 ion microscopes and the UC-HRL scanning ion microprobe. Carbon 14 distribution images obtained by this method show that deoxyadenosine U-C14 is present in the cytoplasm as well as the nucleus, with a higher concentration in\u27 the nucleoli. Our study clearly demonstrates that ion microscopy is well suited for carbon 14 detection and localization at the subcellular level, permitting a wide variety of microanalytical tracer experiments

Comparative aggressiveness of Mycosphaerella pinodes on peas from different regions in western Algeria

Mycosphaerella blight caused by Mycosphaerella pinodes (Berk. et Blox.) Vestergr. is now recognized as one of the major problems limiting yield of pea crops in Algeria. The present work was carried out to study the aggressiveness of 75 M. pinodes isolates collected from different pea-growing areas forming four population groups representing four geographic areas in western Algeria. The latent period, incubation period and disease severity were measured in the greenhouse for each isolate × cultivar combination. All three aggressiveness components differed significantly between isolates and between cultivars. No significant interaction however was noted between isolates and cultivars. Both principal component analysis (PCA) and hierarchical cluster analysis (HCA) were employed to analyze the variation pattern within and between population groups. Cluster analysis, which summarizes the relationship between isolates according to their distance of similarity, sorted isolates into six distinct aggressiveness groups. Aggressiveness group 1 was the most represented, with 34% of all isolates. Both PCA and cluster analysis revealed that many isolates were closely related irrespective of the geographic area or the host cultivar from which they were collected. At the same time, and based on the same aggressiveness components, the cv. Onward, Lucy and DP were the most susceptible, whereas the cv. Rondo and MK were partially resistant

Effect of pea cultivar, pathogen isolate, inoculum concentration and leaf wetness duration on Ascochyta blight caused by Mycosphaerella pinodes

The effect of host leaf wetness duration, Mycosphaerella pinodes inoculum concentration and pathogen isolate on the latent period and the incubation period of the pathogen or disease severity were quantifi ed on pea (Pisum sativum L.). Seedlings of two widely grown pea cultivars, Onward and Merveille de Kelvedon, respectively susceptible and moderately resistant to M. pinodes were subjected to six leaf wetness durations of 6, 12, 24, 48 and 72 h, and inoculated with fi ve inoculum concentrations, 2.5×103, 4×104, 3.5×105, 4x106, and 5.2×107, in order to determine whether the cultivars reacted differently to M. pinodes isolates inoculated under identical conditions. Increasing the duration of leaf wetness and inoculum concentration caused signifi cant (P<0.001) increases in disease severity within each cultivar. Both the incubation period and the latent period decreased with increasing conidial concentration and leaf wetness duration. Generally, the cv. Onward had a signifi cantly shorter incubation period, and latent period and higher disease severity than cv. Merveille de Kelvedon. Isolates differed in aggressiveness at higher levels of leaf wetness (48 h) duration and of inoculum concentration (4×106), but there was no signifi cant interaction between isolates and leaf wetness duration, or between isolates and inoculum concentration. The optimum levels for obtaining a consistent infection and for readily separating the susceptible and the partially resistant cultivars were a leaf wetness of 48 h and an inoculum concentration of 4×106. The study also showed that continuous leaf wetness for 48 h was a threshold for application of fungicides to control the fungus in the susceptible cultivar

Detection of influenza A(H1N1)pdm09 virus in a patient travelling from Shanghai to Italy in July 2018: An uncommon clinical presentation in a non-seasonal period

Influenza is one of the most common infectious diseases in travellers, especially in those returning from subtropical and tropical regions. In late June 2018 an influenza A(H1N1)pdm09 virus infection was diagnosed in a 36-years-old man, returned from a travel in Shanghai and hospitalized at the Ospedale Policlinico San Martino, Genoa, Italy, with a diagnosis of fever and an uncommon clinical presentation characterised by a persistent leukopenia. Phylogenetic analysis revealed a closeness with influenza A(H1N1)pdm09 strains circulating in the US in May-June 2018. Prompt recognition of influenza infection led to a proper case management, demonstrating the crucial role of the continuous influenza surveillance programme

Rs12979860 and rs8099917 single nucleotide polymorphisms of interleukin-28B gene: simultaneous genotyping in Caucasian patients infected with hepatitis C virus

Introduction. Recent studies have demonstrated the role of the interleukin 28B (IL28B) polymorphisms in predicting treatment induced and spontaneous clearance from Hepatitis C virus (HCV) infection, suggesting the possibility of tailored therapy in HCV infected patients. Genome-wide association studies have shown that single nucleotide polymorphisms (SNPs) near IL 28B gene on chromosome 19 are strong predictors of sustained virologic response (SVR) to pegylated interferon and ribavirin. This study was aimed at analyzing the co-prevalence of two common and clinically significant SNPs in a cohort of Ligurian patients. Methods. Two SNPs (rs12979860, rs8099917) were genotyped in the IL28B locus from 175 DNA samples collected from HCV- infected consecutive patients in a Laboratory of Liguria Region, northern Italy. A real-time polymerase chain reaction in a Cor- bett Research Termocycler (Rotor Gene 3000A) by fluorescent probes (Fast Set IL 28B©, Arrow Diagnostics) was used for the detection, according to the manufacturer?s instructions. Results. Carriers of rs12979860CT genotype predominated (87/175, 50%), homozygotes for allele C were 68/175 (39%) and the remaining were homozygotes for IFN-resistant allele T (11%). As for the rs8099917 SNP, genotypes were thus distributed: 96/175 (55%) carried the rs8099917 TT genotype, whereas 70/175 (40%) and 9/175 (5%), were heterozygotes or homozygotes for the G allele. The variants rs12979860CC and rs8099917TT were found in 39% and 54% of overall patients with HCV genotype 1, respec- tively. The combined assessment of examined SNPs resulted in three most prevalent genotypes (rs12979860CC/rs8099917TT, rs12979860CT/rs8099917TG and rs12979860CT/rs8099917TT) with a frequency of 35%, 31% and 18%, respectively. Discussion. Recent findings demonstrated that in carriers of rs12979860CT the determination of additional genotype of rs8099917 SNP could significantly improve the prediction of SVR. In our study cohort carriers of rs12979860CT represented 50% of all patients, who could take advantage with respect to SVR prediction by further determination of the rs8099917 SNP. The simultaneous genotyping of two IL28B SNPs should thus be recommended in HCV infected patients prior to treatment initiation