317 research outputs found
UV lighting in horticulture: A sustainable tool for improving production quality and food safety
Ultraviolet (UV) is a component of solar radiation that can be divided into three types defined by waveband: UV-A (315-400 nm), UV-B (280-315 nm), and UV-C (<280 nm). UV light can influence the physiological responses of plants. Wavelength, intensity, and exposure have a great impact on plant growth and quality. Interaction between plants and UV light is regulated by photoreceptors such as UV Resistance Locus 8 (UVR8) that enables acclimation to UV-B stress. Although UV in high doses is known to damage quality and production parameters, some studies show that UV in low doses may stimulate biomass accumulation and the synthesis of healthy compounds that mainly absorb UV. UV exposure is known to induce variations in plant architecture, important in ornamental crops, increasing their economic value. Abiotic stress induced by UV exposure increases resistance to insects and pathogens, and reduce postharvest quality depletion. This review highlights the role that UV may play in plant growth, quality, photomorphogenesis, and abiotic/biotic stress resistance
Response to 'No evidence of SARS-CoV-2 infection by polymerase chain reaction or serology in children with pseudo-chilblain'. Reply from the authors
Dear Editor, Recalcati et al. conclude that chilblain-like lesions (CLLs) are part of the spectrum of COVID-19 based on reports of SARS-CoV-2 in endothelial cells of skin biopsies assessed by immunohistochemistry and electron microscopy (EM).1 Nevertheless, the conclusion does not seem to be adequately supported by the data. Recalcati et al. expand their previously reported case series to include 32 patients with CLLs. In 21 of 32 cases, no nasopharyngeal swab (NPS) was tested for SARS-CoV-2. Two of 11 patients subjected to molecular testing were positive for SARS-CoV-2, but no serological test was performed to verify the seroconversion. Three patients tested positive for IgM and negative for IgG antibodies without any confirmation of infection through NPS
Image Analysis of Adventitious Root Quality in Wild Sage and Glossy Abelia Cuttings after Application of Different Indole-3-Butyric Acid Concentrations
Adventitious root (AR) formation is a key step in stem cutting propagation of economi-cally important woody ornamentals. Inadequate environmental and hormonal conditions can lead to the production of an insufficient or modest number of ARs in stem cutting, with a consequent decrease in quality. The aim of this research was to optimize wild sage and glossy abelia autumn stem cutting propagation protocols, using image analysis to assess the effects of different IBA concentrations and cultivars on AR quality. For both taxa, the treatments were: four IBA concentrations: 0, 1250, 2500 and 5000 mg L−1 and two cultivars: ‘Little Lucky’ (cv1) and ‘Yellow’ (cv2) from Lantana, and ‘Canyon Creek’ (cv1) and ‘Eduard Goucher’ (cv2) from Abelia. Results show that IBA application is not needed to enhance rooting ability; however, IBA concentration is an important factor determining the best overall AR quality in both taxa. In wild sage applying 5000 mg L−1 IBA improved AR quality in ‘Little Lucky’, increasing the root number, total length, surface area and number of forks and crossings, but decreased quality in ‘Yellow’. In glossy abelia ‘Edouard Goucher’, 5000 mg L−1 IBA increased the root number, but 1250 mg L−1 IBA improved AR quality; ‘Canyon Creek’ did not perform as well as cv2 at these concentrations. This study confirms that sensitivity to IBA dosage varies among species and their cultivars. Findings may help the commercial nursery industry produce higher quality cuttings
Xylella fastidiosa in Olive in Apulia: Where We Stand
A dramatic outbreak of Xylella fastidiosa decimating olive was discovered in 2013 in Apulia, Southern Italy. This pathogen is a quarantine bacterium in the European Union (EU) and created unprecedented turmoil for the local economy and posed critical challenges for its management. With the new emerging threat to susceptible crops in the EU, efforts were devoted to gain basic knowledge on the pathogen biology, host, and environmental interactions (e.g., bacterial strain(s) and pathogenicity, hosts, vector(s), and fundamental drivers of its epidemics) in order to find means to control or mitigate the impacts of the infections. Field surveys, greenhouse tests, and laboratory analyses proved that a single bacterial introduction occurred in the area, with a single genotype, belonging to the subspecies pauca, associated with the epidemic. Infections caused by isolates of this genotype turned to be extremely aggressive on the local olive cultivars, causing a new disease termed olive quick decline syndrome. Due to the initial extension of the foci and the rapid spread of the infections, eradication measures (i.e., pathogen elimination from the area) were soon replaced by containment measures including intense border surveys of the contaminated area, removal of infected trees, and mandatory vector control. However, implementation of containment measures encountered serious difficulties, including public reluctance to accept control measures, poor stakeholder cooperation, misinformation from some media outlets, and lack of robust responses by some governmental authorities. This scenario delayed and limited containment efforts and allowed the bacterium to continue its rapid dissemination over more areas in the region, as shown by the continuous expansion of the official borders of the infected area. At the research level, the European Commission and regional authorities are now supporting several programs aimed to find effective methods to mitigate and contain the impact of X. fastidiosa on olives, the predominant host affected in this epidemic. Preliminary evidence of the presence of resistance in some olive cultivars represents a promising approach currently under investigation for long-term management strategies. The present review describes the current status of the epidemic and major research achievements since 2013
Halophyte common ice plants: A future solution to arable land salinization
The problems associated with the salinization of soils and water bodies and the increasing competition for scarce freshwater resources are increasing. Current attempts to adapt to these conditions through sustainable agriculture involves searching for new highly salt-tolerant crops, and wild species that have potential as saline crops are particularly suitable. The common ice plant (Mesembryanthemum crystallinum L.) is an edible halophyte member of the Aizoaceae family, which switches from C3 photosynthesis to crassulacean acid metabolism (CAM) when exposed to salinity or water stress. The aim of this review was to examine the potential of using the ice plant in both the wild and as a crop, and to describe its ecology and morphology, environmental and agronomic requirements, and physiology. The antioxidant properties and mineral composition of the ice plant are also beneficial to human health and have been extensively examined
A new variant of Xylella fastidiosa subspecies multiplex detected in different host plants in the recently emerged outbreak in the region of Tuscany, Italy
The vector-borne bacterial pathogen Xylella fastidiosa is widely distributed in the Americas; in the last decade it has emerged as a serious threat for agricultural crops, natural environment and landscape in Europe. Following the first EU outbreak in 2013 in southern Italy, associated with a severe disease in olive trees, annual mandatory surveys are now in place in the Member States, leading to the discovery of bacterial outbreaks in different countries. Among the latest findings, an outbreak has been reported in the Italian region of Tuscany, with infections identified in seven different plant species. In this work, we report the isolation and the genetic characterization of isolates associated with this newly discovered outbreak. Multilocus sequence typing approach revealed the occurrence of isolates harbouring a new sequence type, denoted ST87, genetically related to strains of subsp. multiplex, but different from the genotypes of this subspecies previously characterized in Europe. Five cultured strains were successfully recovered from four of the seven host plants, an important achievement for advancing the studies on genomics and pathogenicity of these isolates and thus assess their potential threat for European agriculture
Evaluation of a sampling method for Xylella fastidiosa detection in olive trees
To assess the presence of the xylem-limited bacterium Xylella
fastidiosa subsp. pauca strain CoDiRO in olive trees, a specific
sampling method was evaluated. Symptomatic and symptomless
plants were randomly selected in four olive orchards located in the
province of Lecce (Southern Italy). The crown of each plant was
subdivided into a lower and an upper portion; four samples were
collected from each layer in the main four cardinal directions. A
total of eight samples per plant, composed of one- or two-year-old
asymptomatic twigs, were collected next to branches showing leafscorch
symptoms. In this preliminary study, the null hypothesis was
tested. i.e. there is no difference between the lower and the upper
portions of the tree canopy and across the four cardinal directions. Samples (472), collected from 60 plants belonging to 11 different
olive cultivars, were tested by qPCR. Out of 236 samples taken
from the upper and lower parts of the canopy only 38.1% of lower
samples, in contrast to 56.8% taken from the upper crown layer,
were positive to the bacterium,. The McNemar test determined that
there is a statistically significant difference in the proportion of
positive samples between the upper and lower crown (p < 0.001).
The Cochran’s Q test was performed to evaluate differences in the
four cardinal directions. The null hypothesis suggesting there is
no difference across cardinal directions was confirmed (p = 0.097).
Based on these preliminary results, it appears that sampling should
be directed to the upper part of the canopy. However, further studies
are needed to improve the efficiency of the sampling technique
HIV awareness: A kap study among students in Italy reveals that preventive campaigns still represent a public health priority
Background. Improving knowledge about HIV/AIDS among young people is crucial for preventing new infections. The aim of the study was to investigate knowledge, attitudes and practices regarding HIV infection among students attending university courses related to the healthcare professions, in order to better target future preventive and informative HIV campaigns tailored for young people. Study Design. A knowledge, attitude and practices study was conducted among university students attending the following university courses in Bari (Southern Italy): Medicine and Surgery (MS), Dentistry and Dental Prostheses, Health Assistance, Motor Activities and Sports Sciences, Sciences and Technology of Herbal and Health Products, Nursing, Biomedical Laboratory Techniques, and Dietetics. Methods. Students completed a self-administered questionnaire designed to assess their knowledge/attitudes re/ HIV and their own sexual practices. The general part of the questionnaire requested information about age, gender, nationality, religion and marital status. The second part included questions asking about knowledge, attitude and practices with respect to HIV, which required true/false answers or graduated answers (reported as agree, quite agree, quite disagree, and disagree). Results. Four hundred students were invited to fill in the questionnaire. The response rate was 91.2% (n=365). Almost all students were aware that HIV is transmitted through sexual intercourse and blood, but only 34% knew that breastfeeding is a route of transmission. Of the respondents, 86.8% referred to previous sexual intercourse (25.8% reported using a condom in all cases of sexual intercourse, 43.5% in most cases, 18.6% rarely and 12.1 never). Sexual intercourse with casual partners was reported by 37.5% of these students and 63.9% of them did not always use a condom. Conclusions. The results of the study show that knowledge about some aspects of HIV is insufficient even though the students participating in the present study are students attending university courses related to the healthcare professions. Moreover, high-risk behaviors as the lack of the use of condom during sexual intercourse with casual partners are also common among interviewed students. Programs aimed at providing information that can prevent/reduce transmission of HIV in young people and new strategies to improve knowledge should be stressed as a public health priority
Intercepted isolates of Xylella fastidiosa in Europe reveal novel genetic diversity
After the first confirmed outbreak of Xylella fastidiosa in the European Union (EU), associated with an olive disease denoted olive quick decline syndrome, mandatory surveys are now carried out in the member States and inspections increased at EU entry points such as ports. Such activities led to the interception of X. fastidiosa-infected coffee plants in consignments originating from Central America. Similarly, the geographic expansion of the olive decline epidemic area of the Apulia region (southern Italy) prompted investigations to identify new host plants. Here we report the interception of three novel bacterial sequence types in Italy, based on multi-locus sequence typing, that cluster with different X. fastidiosa subspecies, illustrating the risk of the introduction of additional pathogen genetic diversity into Europe. In the epidemic area of Apulia, new foci as well as host plant species positive with X. fastidiosa, including cherry, myrtleleaf and rosemary, were found to be all infected with the same sequence type of this bacterium (ST53, or CoDiRO strain). This work highlights the limited knowledge of X. fastidiosa phylogenetic and phenotypic diversity, the risk of novel X. fastidiosa introductions via contaminated plant material, and corroborates other studies indicating that the Apulia epidemic emerged from a single introduction of this pathogen into the region
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