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Light flux and quality are crucial factor for setting endogenous plant circadian rhythms. Evaluating the daily rhythmicity of leaf chlorophyll content is an effective method to monitor the plant physiological endogenous clock in response to environmental signals such as light availability/quality. Here, we used a leaf-clip sensor to monitor diurnal rhythms in the content of chlorophyll and flavonoids such as flavonols and anthocyanins in three green- (Ailanthus altissima, Tilia platyphyllos and Platanus × acerifolia) and two red-leafed (Acer platanoides cv. Crimson King and Prunus cerasifera var. pissardii) tree species, adapted to sun (L) or shade (S). Significant differences in chlorophyll content (Chl) and its variations during the day were observed among treatments in all the analyzed species. S-plants had more Chl than L-plants irrespective of leaf color, and Chl variations were more distinct during the day than in L-plants. In particular, contents were lowest in the morning (9:00) and in the middle of the day (at 12:00 and 15:00), and the highest at dusk (21:00). The less evident trends in Chl variation in L-plants were attributed to a decrease in Chl content in high light, which likely masked any increases in the shaded counterparts during the afternoon. Daily flavonol levels did not vary no notably during the day. In sun-exposed red leaves, anthocyanins partially screened mesophyll cells from incident light, and its levels were similar to the Chl dynamics in the shaded counterparts. This study provides new bases for further work on endogenous rhythms of plant pigments and improves our understanding of plant physiology in the context of day/night rhythmicity.

The study of local chestnut and traditional techniques related to their use and consumption are considered of primary importance to promote their nutritional/nutraceutical values. Fruit of four local chestnut cultivars (‘Carpinese’, ‘Pontecosi’, ‘Capannaccia’ and ‘Morona’) from Garfagnana (Italy) were analysed under nutritional and antioxidant aspects and compared with their flour obtained through a traditional thermal-drying process. Raw fruit contained significative amounts of P, K and Mg (~ 149, 1960 and 50 mg 100 g−1 dry weight, respectively) and they were characterised by a good moisture content (~ 49%) and starch (~ 50 g 100 g−1 dw). The traditional thermal-drying processes affected the carbohydrate content of dried chestnut showing a higher sucrose and lower starch content as compared to raw fruits. Traditional thermal-drying processes negatively influenced also total phenol content (TP) and total antioxidant activity: flours from all cultivars contained lower amounts of TP than raw fruit except for ‘Morona’ in which these compounds remained unchanged. This study provides new useful information about the evaluation of nutritional and nutraceutical characteristics of Tuscany local chestnuts and the effects of a traditional thermal-drying processing method, helping consumers and producers to valorise these “forest products”.

The aim was the evaluation of the biochemical and physiological responses of green- (GP) and red-leafed (RP) Prunus cerasifera mature leaves to 20 d of polyethylene glycol (PEG 6000)-induced water stress in order to elucidate a possible ameliorative role exerted by anthocyanins. At 10 d, the anthocyanin content remained unchanged in RP water-stressed leaves. Photosynthetic rate was lower in GP than that of RP (83.4 vs. 76.5%, respectively), paralleled by a higher degree of photoinhibition (Fv/Fm) in GP leaves. Leaves of GP accounted for higher content of soluble sugars at 10 d, when RP only showed a slight sucrose increase. At 20 d of stress, both morphs recovered their Fv/Fm values, suggesting the ability of both genotypes to adjust their photosynthetic metabolism under conditions of water stress. In conclusion, besides the sunscreen role served by anthocyanins, the carbon sink by these flavonoids might have further prevented sugar accumulation and the consequent sugar-promoted feedback regulation of photosynthesis in drought-stressed red leaves.

Trees play a pivotal role in the urban environment alleviating the negative impacts of urbanization, and for this reason, local governments have promoted strongly tree planting policies. However, poor soil quality and neglect tree maintenance (e.g., irrigation and fertilization) can seriously mine the plant health status during the tree establishment phase. The use of biochar to provide long-lasting C to the soil and, at the same time, improving soil properties (e.g., improved water holding capacity), soil enzymes activities and NPK concentrations, is a promising research field. Therefore, with a two-step experiment, the study aimed to assay the physiological responses of a commonly used urban tree species (Tilia × europaea L.) to 1.5 % (w/w) biochar amendment (B), and secondly, to assess the ability of trees, grown in biochar amended soil, to tolerate a period of drought. Biochar amendment increased P and K availability in the soil, resulting in higher P and K concentrations in B than control leaves, according to the leaf stage. This induced B trees, higher values in both total biomass than controls (+22 %) in well-watered plants. Moreover, the higher water availability in soil amended with biochar helped B trees to tolerate water stress, with better leaf photosynthetic performances and a faster recovery than stressed controls after the re-watering. This study highlights the dual function of the biochar, improving CO

Ancient apple cultivars are known for their organoleptic properties over a small geographic area, but little is known of their nutraceutical properties, which might be useful in large-scale breeding programmes. Nine ancient apple cultivars from Tuscany (Italy) were characterized for their organoleptic properties, phenolic profiles, and antioxidant activity. These cultivars had high polyphenol concentrations (principally flavanols and phenolic acids) and high total antioxidant capacity compared with most commercial apple cultivars. Fruits from the cultivars 'San Michele' and 'Del Debbio' showed a good compromise between fruit size and solid soluble content, and might be suitable for fresh consumption, while fruit from 'Benito', 'Della Piastra', 'Lugliese Grisanti', 'Del Sangue' and 'Ruggine' had high polyphenol contents and excellent antioxidant capacity, and may be suitable for breeding programmes. 'Ruggine' fruit could also be used for sweet juices with good nutraceutical properties due to their high soluble solid content and high flavanol concentration.

Many physiological parameters were compared to identify the most sensitive and reliable indicator of grapevine water status. One-year-old potted grapevines (Vitis vinifera L., cvs. ‘Sangiovese’ and ‘Cabernet Sauvignon’) were studied under two irrigation treatments: 100% and 0% of daily water consumption. Measurements of pre-dawn (PD) and midday (MD) leaf water potential (Ψw), MD stem water potential (ΨS), leaf temperature (T°L) and stomatal conductance (gS) were taken throughout twenty days and analyzed in conjunction with climatic data, relative cumulative sap flow (RCSF) and the maximum daily shrinkage (MDS) of the vine stock. Physiological indicators showed substantial differences in sensitivity. The first indication of changes in vine water status was the increase of MDS and the decrease of gS. MDS and RCSF revealed significant differences between the two irrigation treatments even when PDΨw, up to now widely accepted as the benchmark of water status indicators, did not show any significant variation. Measurements of water potential showed ΨS to be a better indicator of vine water status than Ψw and T°L. In conclusion, we classified the tested indicators according to a descending order of their early detection capability: gS = MDS > RCSF > PDΨw = MDΨS > T°L > MDΨw.

BackgroundOrthorexia nervosa (ON) is an emerging condition featuring restrictive eating behaviors on the basis of subjective beliefs about food healthiness. Many authors have stressed the similarities between ON and anorexia nervosa (AN) in both cognitive and behavioral patterns. Despite that, while the link between AN and female autism presentations is well known in the literature, no study has yet investigated the relationship between ON and autism spectrum. This work aims to investigate the relationship between ON and autistic traits in a university population.MethodsAn e-mail invitation was sent to all the students and University workers of University of Pisa. Subjects were asked to fulfill the ORTO-15 and the Adult Autism Subthreshold spectrum (AdAS spectrum) questionnaires.ResultsA total of 2426 subjects joined the survey: 623 subjects (26.3%) reported a score associated with significant orthorexic symptoms according to ORTO-15 (ON group), while 1789 subjects (73.7%) did not report ON symptomatology and were considered as healthy controls (HC). The ON group scored significantly higher on almost all AdAS spectrum domains. Moreover, being female and scoring higher on AdAS spectrum were statistically predictive factors for the presence of ON symptomatology. Among AdAS spectrum domains, higher scores on AdAS spectrum inflexibility and adherence to routine and restricted interests and rumination domains, as well as lower scores on verbal communication domain, were statistically predictive of orthorexic symptoms.ConclusionsOur findings highlight an overlap between ON and autism spectrum psychopathology. Further studies are needed to clarify the relationship between restrictive eating disorders and female autism phenotypes.

Summary • The differential accumulation of various polyphenols, particularly of flavonoids and hydroxycinnamates, was studied in leaves of Ligustrum vulgare exposed to increasing sunlight under well watered or drought-stress conditions. • Light- and drought-induced changes in leaf polyphenol concentrations were normalized to the CO2 assimilation rate. The functional roles of flavonoids and hydroxycinnamates were analysed through tissue localization using multispectral fluorescence microimaging, and through efficiencies to scavenge superoxide radicals (O2−) and to screen UV wavelengths. • Clear effects of light and water treatments on leaf polyphenol concentrations were not observed, as the CO2 assimilation rate varied according to sunlight and water availability. However, biosynthesis of quercetin 3-O-rutinoside, luteolin 7-O-glucoside and echinacoside, which were efficient O2− scavengers, increased sharply in response to solar radiation. By contrast, carbon for the synthesis of p-coumaric acid and monohydroxyflavones, efficient UV screeners but poor O2− scavengers, did not vary depending on light treatments. Flavonoids accumulated in both the adaxial epidermis and the palisade tissue because of sunlight irradiance, whereas echinacoside occurred largely in abaxial tissues. • We hypothesize that flavonoids may serve antioxidant functions in response to excess light and drought stress, and that a coordinate control system between hydroxycinnamate and flavonoid pathways operated in L. vulgare exposed to excess light.

In this work, we propose to transfer a soil moisture-based wireless sensor network (SM-WSN) to support the reduction of irrigation water consume in the Tuscany region (Italy). The SM-WSN was designed and validated in a commercial pear orchard during two growing seasons (2019-2020) in which the smart irrigation strategy was implemented and applied.Initially, the micro irrigation system was assessed based on its performance in terms of water distribution uniformity (DU) evaluated with field measurements of emitter flow rates. Then, a zoning analysis was carried out to divide the orchard into homogeneous areas according to the normalized difference vegetation index (NDVI) detected with unmanned aerial vehicle (UAV) and GIS tools. These areas were used to define the topology of the SM-WSN and to investigate how water distribution uniformity can affect the vigour of the trees. A total of 6 “drill & drop” capacitance probes (Sentek Pty Ltd, Stepney, Australia) were installed in the field, after following a simplified laboratory calibration procedure. The hardware and the smartphone-based application, AgriNET, used to download from remote the sensors’ readings were provided by Tuctronics (Walla Walla, Washington, USA).Assuming that the zoning outcome was only associated with the soil spatial variability, the effect of DU on the vigour of the trees has been identified. Moreover, unlike the ordinary irrigation scheduling applied in the farm, the smart system allowed maintaining the soil water content within a pre-defined optimal range, in which the upper and lower limits corresponded respectively to the soil field capacity and the threshold below which water stress occurs. Based on the smart irrigation management, a water-saving up to 50% of the total water supplied with ordinary scheduling was achieved during both the investigated growing seasons. Moreover, the quality of the productions (i.e °Brix, fruit size and firmness) were in line with the standard required by the farmer. The adoption of the new technology, aiming at identifying the most appropriate irrigation management, has the potential to generate positive economic returns and to reduce the environmental impacts.

Selected light wavebands promote plant development and/or the biosynthesis of targeted metabolites. This work offers new insights on the effects of red (R), green (G), blue (B), and white (W - R:G:B; 1:1:1) LED light supplementation on physiochemical traits of strawberry leaves. Gas exchange and chlorophyll fluorescence parameters, photosynthetic pigments, and superoxide anion (*O2-) content were analysed in plants grown for 1 (T1) and 17 (T17) d with light supplementations. At T1, light supplementations resulted in the enhancement of the de-epoxidation state of xanthophylls and nonphotochemical quenching, but no changes were observed in maximal photosynthetic rate (PNmax), irrespective of light spectra. At T17, xanthophyll contents remained higher only in R-supplemented plants. Overall, W light resulted in higher photosynthesis, whilst R and B light depressed PNmax values and promoted *O2- formation at T17. G light did not induce variations in photosynthetic traits nor induced oxidative stress at both T1 and T17.

New technologies in agriculture present the opportunity to create intuitive and user-friendly decision support systems, and to improve the productivity of the systems requiring water and energy. In the last few years, the adoption of these technologies have been increasing through third mission activities, and the collaboration between researchers, consultants, agri-food managers and farmers.The general objective of the proposed dissemination activity carried out by the AgrHySMo laboratory of the University of Pisa, was to transfer a soil moisture-based wireless sensor network (SM-WSN) to a commercial pear orchard named Illuminati Frutta (Arezzo, Italy), for the feedback control of irrigation.The plan of the third mission activity was designed by the following phases: i) the team evaluated the hydraulic performance and management of the irrigation system in the pear orchard; ii) the use of proximal sensing provided the NDVI for the biophysical characterization of the crop in a pilot area extended thirteen ha; iii) the open-source QGIS suite program was used to elaborate the collected images, to assess a zoning analysis, and to discretize homogeneous areas inside the orchard. These zoning maps were used to define the topology of the SM-WSN.The orchard was characterized by four homogeneous zones, inside which at least one sensor of soil water content (FDR Drill and Drop probe, Sentek Inc.) was installed. A total of 6 probes were installed in the pilot area. The hardware and the smartphone of the dedicated sensor network applications, AgriNET, were provided by Tuctronics (Walla Walla, Washington, USA). The measurements of volumetric soil water contents are sent to a platform using the MODBUS RTU protocol interfaced with a communication board and then delivered, using the cellular 3G data network, to a MySQL database operated by AgriNET/Tuctronics accessible from the web. According to the ordinary scheduling of irrigation, the expert system allowed the farmer to maintain the soil water content within a pre-defined optimal range, which upper limit corresponds to the soil field capacity and the lower is the threshold below which water stress occurs. During the first experimental growing season, by considering the results obtained in the pilot plot, compared with the ordinary irrigation scheduling the farmer saved up to 35% of the water and energy supply. In the future, the proposed feedback control of irrigation protocol will be extended to the entire farm. Thus, the adoption of this new technology aimed at identifying the most appropriate irrigation management, have the potential to generate positive economic returns and to reduce the environmental impacts.

The final stage of leaf ontogenesis is represented by senescence, a highly regulated process driven by a sequential cellular breakdown involving, as the first step, chloroplast dismantling with consequent reduction of photosynthetic efficiency. Different processes, such as pigment accumulation, could protect the vulnerable photosynthetic apparatus of senescent leaves. Although several studies have produced transcriptomic data on foliar senescence, just few works have attempted to explain differences in red and green leaves throughout ontogenesis. In this work, a transcriptomic approach was used on green and red leaves of Prunus cerasifera to unveil molecular differences from leaf maturity to senescence. Our analysis revealed a higher gene regulation in red leaves compared to green ones, during leaf transition. Most of the observed DEGs were shared and involved in transcription factor activities, senescing processes and cell wall remodelling. Significant differences were detected in cellular functions: genes related to photosystem I and II were highly down-regulated in the green genotype, whereas transcripts involved in flavonoid biosynthesis, such as UDP glucose-flavonoid-3-O-glucosyltransferase (UFGT) were exclusively up-regulated in red leaves. In addition, cellular functions involved in stress response (glutathione-S-transferase, Pathogen-Related) and sugar metabolism, such as three threalose-6-phosphate synthases, were activated in senescent red leaves. In conclusion, data suggests that P. cerasifera red genotypes can regulate a set of genes and molecular mechanisms that cope with senescence, promoting more advantages during leaf ontogenesis than compared to the green ones.

In the context of global warming, mild winter temperatures could compromise the fulfilment of the chilling requirement (CR) for overcoming flower bud endodormancy, impacting on the yields of perenn...

The feedback regulation of photosynthesis depends on the cooperation of multiple signals, including sugars. Herein, the effect of shoot girdling was monitored on a daily basis for three days in green- and red-leafed Prunus cerasifera plants (GLP and RLP, respectively). The effect of anthocyanin presence was investigated in terms of photosynthesis, sugar metabolism and photoprotection. Net photosynthesis (A390) and stomatal conductance were reduced on the first day at 12:00 only in the girdled GLP (29 and 33 %, respectively). Moreover, the girdled GLP displayed at 12:00 higher sucrose, glucose and fructose concentrations than control leaves. Conversely, girdled RLP showed the first reduction of A390 at 18:00, with no significant differences at 12:00 in sucrose and glucose concentrations. The increased biosynthesis of anthocyanins that was only detected in girdled RLP contributed to lowering the accumulation of hexoses. Overall, these results revealed a sugar-buffering role exerted by anthocyanins that positively influence the feedback regulation of photosynthesis. Moreover, non-photochemical quenching, namely pNPQ, revealed the ability of anthocyanins to photoprotect photosystem II from supernumerary photons reaching the chloroplast, whose function was compromised by girdling. The present study provides a starting point to understand the possible link between photosynthesis regulation through sugar signalling and anthocyanin upregulation.

Current climate change negatively impacts on key seasonal biological processes of perennial plants causing erratic productions and, consequently, significant yield reductions. Being flowering time of fruit crops one of the most widely used indicators for climate change studies, the present research aimed to assess, over a long-term period (1973–2016), the climatic trend and its influence on blooming date and intensity of 40 apricot cultivars (Prunus armeniaca L.) grown in central Italy. Over the autumn-spring seasons, the main climatic parameters (temperature, rainfall) were acquired, and calculation of chill accumulation according to the Chilling Units model (CU) was performed. Results showed significant trends in warming of autumn-winter monthly minimum and average temperatures, particularly since the 1990s. During the critical period for overcoming of flower bud endodormancy, a dramatic loss of CUs was recorded. Most of the examined cultivars, belonging to Italian and foreign germplasm and opportunely selected for different flowering time, showed important blooming delays and blooming intensity decreases. In particular, the early-blooming cultivars showed the highest average shift of around 12 days and a loss in blooming intensity score which fell to levels of around 50% with respect to previous periods. The CUs, negatively correlated with blooming time and positively correlated with blooming intensity, seem to be crucial for apricot floral biology. The irregular autumn-winter cold rate of recent years may mean that substantial impacts can be expected in the future with possible geographic shifts of the apricot cultivation areas towards more potentially suitable areas located in the northern Italian and European regions, with considerable socioeconomic inference.

The present study reviews the research on the FAO56 crop coefficients of fruit trees and vines performed over the past twenty years. The main objective was to update information and extend tabulated single (K c ) and basal (K cb ) standard crop coefficients. The selection and analysis of the literature for this review have been done to consider only studies that adhere to FAO56 method, computing the reference ET with the FAO Penman–Monteith​ ET o equation and field measuring crop ET with proved accuracy. The crops considered refer to vine fruit crops, berries and hops, temperate climate evergreen fruit trees, temperate climate deciduous fruit trees and, tropical and subtropical fruit crops. Papers satisfying the conditions expressed above, and that studied the crops under pristine or appropriate eustress conditions, were selected to provide for standard K c and K cb data. Preference was given to studies reporting on the fraction of ground cover (f c ), crop height (h), planting density, crop age and adopted training systems. The K c and K cb values obtained from the selected literature generally show coherence relative to the crop biophysical characteristics and reflect those characteristics, mainly f c , h and training systems. The ranges of reported K c and K cb values were grouped according to crop density, particularly f c and h, and were compared with FAO56 (Allen et al., 1998) previously tabulated K c and K cb values, as well as by Allen and Pereira (2009) and Jensen and Allen (2016), which lead to define update indicative standard K c and K cb values. These values are aimed for use in crop water requirement computations and modeling for irrigation planning and scheduling, thus also aimed at supporting improved water use and saving in orchards and vines.

Girdling is a widespread agronomic technique to increase the fruit quality characteristics (e.g. size, solid soluble content [SSC] and colour). However, the information on the fruit metabolic changes related to this practice still remains unclear and fragmentary. Moreover, girdling duration and application time may greatly affect the plant/fruit metabolic responses producing sometimes counterproductive results. Fruit quality, metabolomic and antioxidant analyses were conducted to characterise the effects of two different girdling dates (4- and 2-weeks before the harvest, 4 W and 2 W, respectively) in skin and pulp of red-fleshed plum (Prunus cerasifera var. pissardii). Overall, the pulp metabolism was altered in both 4 W and 2 W Girdling by inducing accumulation of sugars (sucrose and trehalose), sugar alcohols (inositol and xylitol), organic acids (especially some TCA cycle intermediates such as α-ketoglutaric, citric, isocitric, fumaric and malic acid), amino acids (s-alanine and L-proline), anthocyanins and other phenols. In the skin only girdling 4 W showed major significant differences compared to the control increasing the fruit quality characteristics (size, SSC, dry matter and red colour) and showing greater metabolic changes with respect to the controls. Furthermore, the total antioxidant activity was also increased in both skin and pulp respect to other treatment only in Girdling 4 W. This approach could be used with both P. cerasifera plums as well as other red-fleshed fruit species in order to ensure red-fleshed fruits production with a uniform red colouration and higher content of bioactive compounds.

The growth of agricultural mechanization has promoted an increase in raspberry production, and for this reason, the best postharvest storage and processing techniques capable of maintaining the health beneficial properties of these perishable berry fruits have been widely studied. Indeed, raspberries are a rich source of bioactive chemical compounds (e.g., ellagitannins, anthocyanins, and ascorbic acid), but these can be altered by postharvest storage and processing techniques before consumption. Although there are clear differences in storage times and techniques, the content of bioactive chemical compounds is relatively stable with some minor changes in ascorbic acid or anthocyanin content during cold (5 °C) or frozen storage. In the literature, processing techniques such as juicing or drying have negatively affected the content of bioactive chemical compounds. Among drying techniques, hot air (oven) drying is the process that alters the content of bioactive chemical compounds the most. For this reason, new drying technologies such as microwave and heat pumps have been developed. These novel techniques are more successful in retaining bioactive chemical compounds with respect to conventional hot air drying. This mini-review surveys recent literature concerning the effects of postharvest storage and processing techniques on raspberry bioactive chemical compound content.

Despite the huge biodiversity characterizing the Mediterranean environment, environmental constraints, such as high sunlight and high temperatures alongside with dry periods, make plant survival hard. In addition, high irradiance leads to increasing ozone (O3 ) concentrations in ambient air. In this era of global warming, it is necessary to understand the mechanisms that allow native species to tolerate these environmental constraints and how such mechanisms interact. Three Mediterranean oak species (Quercus ilex, Quercus pubescens and Quercus cerris) with different features (drought tolerant, evergreen or deciduous species) were selected to assess their biometrical, physiological and biochemical responses under drought and/or O3 stress (80-100 nl l(-1) of O3 for 5 h day(-1) for 77 consecutive days). Leaf visible injury appeared only under drought stress (alone or combined with O3 ) in all three species. Drought × O3 induced strong reductions in leaf dry weight in Q. pubescens and Q. cerris (-70 and -75%, respectively). Alterations in physiological (i.e. decrease in maximum carboxylation rate) and biochemical parameters (i.e. increase in proline content and build-up of malondialdehyde by-products) occurred in all the three species, although drought represented the major determinant. Quercus ilex and Q. pubescens, which co-occur in dry environments, were more tolerant to drought and drought × O3 . Quercus ilex was the species in which oxidative stress occurred only when drought was applied with O3 . High plasticity at a biochemical level (i.e. proline content) and evergreen habitus are likely on the basis of the higher tolerance of Q. ilex.

There is a lack of knowledge about the possibility that plants facing abiotic stressors, such as drought, have an altered perception of a pulse of O3 and incur in alterations of their signalling network. This poses some concerns as to whether defensive strategy to cope episodic O3 peaks in healthy plants may fail under stress. In this study, a set of saplings of two Mediterranean deciduous species, Quercus cerris and Q. pubescens, was subjected to water withholding (20% of daily evapotranspiration for 15 days) while another set was kept well-watered. Saplings were then subjected to a pulse of O3 (200 nl l−1 for 5 h) or maintained in filtered air. Q. pubescens had a more severe decline of photosynthesis and leaf PDΨw (about −65% and 5-fold lower than in well-watered ones) and events of cell death were observed under drought when compared to Q. cerris, which is supportive for a higher sensitivity to drought exhibited by this species. When O3 was applied after drought, patterns of signalling compounds were altered in both species. Only in Q. pubescens, the typical O3-induced accumulation of apoplastic reactive oxygen species, which is the first necessary step for the activation of signalling cascade, was completely lost. In Q. cerris the most frequent changes encompassed the weakening of peaks of key signalling molecules (ethylene and salicylic acid), whereas in Q. pubescens both delayed (salicylic and jasmonic acid) or weakened (ethylene and salicylic acid) peaks were observed. This is translated to a higher ability of Q. cerris to maintain a prompt activation of defensive reaction to counteract oxidative damage due to the pollutant. Our results reveal the complexity of the signalling network in plants facing multiple stresses and highlight the need to further investigate possible alteration of defensive mechanism of tree species to predict their behavior.

Anthocyanic morphs are generally less efficient in terms of carbon gain, but, in turn, are more photoprotected than anthocyanin-less ones. To date, mature leaves of different morphs or leaves at different developmental stages within the same species have generally been compared, whereas there is a lack of knowledge regarding different stages of development of red vs. green leaves. Leaves (1-, 7-, and 13-week-old) of red- (RLP) and green-leafed (GLP) Prunus in terms of photosynthetic rate, carbon metabolism and photoprotective mechanisms were compared to test whether anthocyanin-equipped leaves perform better than anthocyanin-less leaves and whether photoprotection is the primary role of epidermally-located anthocyanins, using for the first time a recently-developed parameter of chlorophyll fluorescence (qPd). GLP leaves had a higher photosynthetic rate in 1- and 7-week-old leaves, but RLP leaves performed better at an early stage of senescence and had a longer leaf lifespan. Anthocyanins contributed to leaf photoprotection throughout the leaf development, but were tightly coordinated with carotenoids. Besides photoprotecting, we propose that epidermal anthocyanins may be principally synthetized to maintain an efficient carbon-sink strength in young and senescent leaves, thus extending the RLP leaf lifespan.

This paper presents an automated approach for peach fruit maturity grading that, by exploiting fiber-optic spectroscopy-based sensors and multivariate processing techniques, minimizes the operator intervention while reducing discharge and waste. The use of a spectroscopic sensor complies with the so-called nondestructive measurement method, which enables fast repeated measurements to be performed at the single fruit level while avoiding fruit damage and loss. Maturity grading is accomplished by retrieving estimates of the fruit flesh firmness by means of multivariate retrieval techniques applied to the reflectance spectra acquired with the spectrometer and by processing the retrieved values within the framework of a maturity fuzzy classifier. A decision support system is developed to provide the user with maturity category decision and associated reliability. Experimental results show that the approach is effective for automated maturity grading of peach fruits affected by a high degree of variability. This paper lays the foundations for the realization of easy-to-use sustainable automated maturity grading systems.

In this work, we tested the hypothesis that ascorbic acid (AA) reduces browning of fresh-cut apples (Red Delicious, RD, and Granny Smith, GS), and we investigated the impact of AA on phenylpropanoid metabolism of RD and GS. Apple slices were dipped in a solution of 100 mg/L of chlorine dioxide (ClO2) and ClO2 + 3% AA and stored at 4C for 96 h. Flesh firmness, solid soluble content and browning index, total phenols and flavonoids, and the activity of peroxidase and polyphenol oxidase were monitored upon storage (0, 48 and 96 h). Our results demonstrated that GS is less sensitive to browning and thus more suitable for minimally processed produce. Ascorbate reduces the browning index also in RD, a cultivar largely appreciated by consumers but more prone to browning. AA likely contrasts browning appearance by interacting with peroxidase and polyphenol oxidase and/or promoting the regeneration of phenols and flavonoids. Practical Applications Browning of fresh-cut apple is one of the main problems that limit the shelf life of this type of produce. Given that this produce is highly appreciated by consumers, different antibrowning treatments have been tested to extend the shelf life of fresh-cut apple. We found that treatment with 100 mg/L of ClO2 + 3% of ascorbic acid significantly reduces the browning appearance in apple slices. Browning was also reduced in Red Delicious cultivar that is more prone than Granny Smith to this phenomenon, but that is highly appreciated by consumers.

Global climate change represents a moving target for plant acclimation and/or adaptation, especially in the Mediterranean basin. In this study, the interactions of severe drought (20% of the effective daily evapotranspiration) and O3 fumigation (80 ppb, 5 h day−1, for 28 consecutive days) on (i) photosynthetic performance, (ii) cell membrane stability, (iii) hydric relations, (iv) accumulation of compatible solutes, and (v) lipophilic antioxidant compounds were investigated in young Quercus cerris plants. In addition to the typical drought-induced stomatal closure, imposition of water withholding dramatically influenced the profile of stress-associated metabolites, i.e., abscisic acid (ABA), proline, and lipophilic antioxidants. However, plants were not able to delay or prevent the negative effects of water deficit, the greatest impacting factor in this study. This translated into a steep decline of photosynthetic efficiency, leaf hydration, and membrane fluidity and permeability. When water stress was coupled with O3, plants orchestrated cross-talk among ABA, proline, and sugar in fully-expanded mature leaves, partially leading to a premature senescence.

The predicted effects of global change (GC) will be exacerbated in the more densely populated cities of the future, especially in the Mediterranean basin where some environmental cues, such as drought and tropospheric ozone (O3) pollution, already mine seriously plant survival. Physiological and biochemical responses of a Mediterranean, evergreen, isohydric plant species (Quercus ilex) were compared to those of a sympatric, deciduous, anisohydric species (Q. pubescens) under severe drought (20% of the effective daily evapotranspiration) and/or chronic O3 exposure (80 ppb for 5 h day−1 for 28 consecutive days) to test which one was more successful in those highly limiting conditions. Results show that (i) the lower reduction of total leaf biomass of Q. ilex as compared to Q. pubescens when subjected to drought and drought × O3 (on average −59 vs −70%, respectively); (ii) the steeper decline of photosynthesis found in Q. pubescens under drought (−87 vs −81%) and drought × O3 (−69 vs −59%, respectively); (iii) the increments of malondialdehyde (MDA) by-products found only in drought-stressed Q. pubescens; (iv) the impact of O3, found only in Q. pubescens leaves and MDA, can be considered the best probes of the superiority of Q. ilex to counteract the effect of mild-severe drought and O3 stress. Also, an antagonistic effect was found when drought and O3 were applied simultaneously, as usually happens during typical Mediterranean summers. Our dataset suggests that on future, the urban greening should be wisely pondered on the ability of trees to cope the most impacting factors of GC, and in particular their simultaneity.

Fresh-cut produce represents a good method to save about 25% of the kiwifruit not useful to meet the fresh fruit-marketing standard due to improper size and shape. For that reason, fresh-cut kiwifruit has been extensively studied. However, the comprehension of the influence of some aspects of cultivation might further increase the shelf life as well as the nutritional values of that fruit. This study explored the hypothesis that kiwifruits grown fully exposed to sunlight or partially shaded differently perform upon storage as whole fruit and as minimally processed produce. Flesh firmness (FF), total solids soluble (SSC), ascorbate (AAT), flavonoids (TFO), and phenols (TF) contents were evaluated in sliced and whole fruit upon 3 days of storage at 4 °C after 75 days of cold chamber storage at 0 °C. The activities of two enzymes related to the softening process, polygalacturonase (PG) and pectinmethylesterase (PME), were evaluated as well. FF and SSC were constitutively higher in sun-exposed fruit, and those characteristics remained higher during the storage as whole fruit. Greater constitutive content of AAT, TFO, and TP was found in sun-exposed whole fruit, although after cutting the reduction in their content was significantly lower in shaded fruits. PME and PG activities were higher only in whole shaded fruits, whereas no relevant differences occurred after cutting. In summary, sun-exposed fruits were more suitable for the fresh-fruit market, whereas the shaded counterpart displayed a good predisposition for use as fresh-cut produce, maintaining similar fruit maturity properties but higher nutraceutical values when sliced than fruit grown under full sun.

Ancient apple cultivars usually have higher nutraceutical value than commercial ones, but in most cases their variability in pomological traits does not allow us to discriminate among them. Fruit of two Tuscany ancient apple cultivars, &lsquo, Casciana&rsquo, and &lsquo, Rotella&rsquo, picked from eight different orchards (four for each cultivar) were analyzed for their pomological traits, organoleptic qualities, polyphenolic profile and antiradical activity. The effectiveness of a polyphenol-based cluster analysis was compared to molecular markers (internal transcribed spacers, ITS1 and ITS2) to unequivocally discern the two apples. &lsquo, fruit had a higher nutraceutical value than some commercial cultivars, in terms of phenolic abundance, profile and total antiradical activity. Although pedo-climatic conditions of different orchards influenced the phenolic profile of both apples, the polyphenolic discriminant analysis clearly separated the two cultivars, principally due to higher amounts of procyanidin B2, procyanidin B3 and p-coumaroylquinic acid in &lsquo, than in &lsquo, fruit. These three polyphenols can be used proficiently as biochemical markers for distinguishing the two apples when pomological traits cannot. Conversely, ITS1 and ITS2 polymorphism did not allow us to distinguish &lsquo, from &lsquo, fruit. Overall, the use of polyphenolic fingerprint might represent a valid tool to ensure the traceability of products with a high economic value.

Ozone (O3) and salinity are usually tested as combined factors on plant performance. However, the response to a single episode of O3 in plants already stressed by an excess of NaCl as occurs in the natural environment has never been investigated, but is important given that it is commonly experienced in Mediterranean areas. Three-year-old Quercus ilex L. (holm oak) saplings were exposed to salinity (150 mM NaCl, 15 days), and the effect on photosynthesis, hydric relations and ion partitioning was evaluated (Experiment I). In Experiment II, salt-treated saplings were exposed to 80 nl l-1 of O3 for 5 h, which is a realistic dose in a Mediterranean environment. Gas exchanges, chlorophyll fluorescence and antioxidant systems were characterized to test whether the salt-induced stomatal closure limited O3 uptake and stress or whether the pollutant represents an additional stressor for plants. Salt-dependent stomatal closure depressed the photosynthetic process (-71.6% of light-saturated rate of photosynthesis (A380)) and strongly enhanced the dissipation of energy via the xanthophyll cycle. However, salt-treated plants had higher values of net assimilation rate/stomatal conductance (A/gs) than the controls, which was attributable to a greater mesophyll conductance gm/gs and carboxylation efficiency (higher gm/maximal rate of Rubisco carboxylation (Vcmax)), thus suggesting no damage to chloroplasts. O3 did not exacerbate the effect of salinity on photosynthesis, however a general enhancement of the Halliwell-Asada cycle was necessary to counteract the O3-triggered oxidative stress. Despite the 79.4% gs reduction in salt-stressed plants, which strongly limited the O3 uptake, a single peak in the air pollutant led to an additional burden for the antioxidant system when plants had been previously subjected to salinity.

A new frontier of nondestructive measurement exploitation is explored in this paper as concerns the food traceability and control arena. Presented is a method for nondestructive automated peach tree rootstock classification by means of high spectral resolution spectroscopy and multivariate signal processing. Many studies have shown that rootstock has significant impact on the quality and maturity of peach fruits. Rootstock knowledge not only enables fruit traceability but also helps in selecting the best storage condition and marketing channel. A novel automated method is presented to classify peach fruits with respect to their rootstock based on multivariate signal processing of fruit skin reflectance spectra, which are highly affected by physical and biochemical phenomena associated with fruit quality and maturity. The experimental results exploiting measurements of fruit skin reflectance spectra acquired in the visible and near infrared ranges with a high-resolution spectrometer show that automated rootstock classification by spectroscopic measurements and signal processing techniques is feasible and effective and has great potential in horticultural engineering.

BACKGROUND: The effect of 1-methylcyclopropene (1-MCP) treatment and two different post-controlled atmosphere air storage (PCAAS) durations on the quality and chemistry of fresh-cut Ambrosia apple slices was studied. RESULTS: PCAAS for 1 or 2 weeks prior to slicing had an overall positive effect on the resultant quality of fresh-cut apple slices. The most significant responses to PCAAS were the suppression of both phenolic and o-quinone accumulation in slices, and this was related to the significantly lower browning potential values obtained for slices from PCAAS-treated apples. Polyphenol oxidase (PPO), peroxidase (POX) and ascorbate peroxidase (APOX) activities were not affected by 1-MCP or PCAAS treatments. PPO and POX activities were almost completely inhibited by a 50 g L−1 calcium ascorbate anti-browning dip of apple slices from all treatments. CONCLUSION: The most dramatic effect of the PCAAS treatments was to reduce the accumulation of soluble phenolics, which is likely the reason that o-quinone accumulation was also inhibited in treated fruits. The consequent reduction in browning potential may be the explanation as to why PCAAS treatment has been shown to reduce fresh apple slice browning in previous work. Copyright © 2012 Society of Chemical Industry