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[EN] Charred organic matter is recently receiving attention for its potential use as soilless growth medium. However, depending on its origin and on the manufacturing technology, it can result toxic for plants. This fact implies that a detoxifying treatment ought to be devised in order to reclaim char in this way. We have studied three materials which combine these factors: two pyrolyzed biochars, one from forest waste (BCH-FW) and another from olive mill waste (BCH-OMW), and one hydrothermally carbonized hydrochar from forest waste (HYD-FW). These materials are suspicious of phytotoxicity due to their high pH, high salinity, or presence of organic toxics. For these new materials, it is mandatory to select fast and reliable bioassays to predict their potential phytotoxicity. In order to achieve this goal water extracts of the three chars were subjected to bioassays of seed germination and bioassays of seedling growth in hydroponic conditions. The biochar from olive mill waste and the hydrochar, but not the biochar from forest waste, showed considerable phytotoxicity as seed germination and plant growth were negatively affected (e.g. BCH-OMW reduced seed germination by 80% and caused early seedling death). In order to adjust pH and electrical conductivity for plant growth, treatments of acidification and salt leaching with optimal diluted HNO3 solutions (03 N, 0.2 N, and 0.75 N for BCH-OMW, BCH-FW, and HYD-FW, respectively) as calculated from titration curves, were conducted. The acid treatment reduced electrical conductivity in BCH-OMW (from 9.2 to 4.5 dS m(-1)), pH (maximum in BCH-FW from 9.6 to 6.2) and water soluble carbonaceous compounds (maximum in HYD-FW from 5969 to 2145 mg kg(-1)) in the three chars, and increased N content (maximum in BCH-OMW from 50 to 6342 mg kg(-1)) in the three chars. Bioassays on acid-treated chars demonstrated the absence of phytotoxicity and even stimulation of seedling growth over the control (increase of 86% and 56% for BCH-FW and

[EN] Biomass waste from rice straw has many management problems, including field firing causing severe air pollution and natural organic decomposition resulting in methane emission. The conversion of this waste to ashes may offer the possibility of reusing them in cementing systems. For the first time ashes from different parts of the rice plant (Oryza sativa) were characterised from the chemical composition point of view: rice leaf ash (RLA), rice leaf sheath ash (RlsA) and rice stem ash (RsA). Microscopic studies on ashes revealed heterogeneity in the distribution of chemical elements in the remaining cellular structure (spodograms). The highest concentration of SiO2 was found in dumbbell-shaped phytoliths (%SiO2 > 78%). In the global chemical composition of ashes, SiO2 was also the main oxide present. According to Vassilev¿s classification of chemical composition, RLA belongs to the K-MA zone (medium acid), RlsA to the K-zone (low acid) and RsA to the S-zone (high acid). Calcination temperatures ¿550 ¿C completely removed organic matter from the straw and ashes underwent significant sinterisation by calcining at 650 ¿C due to the presence of potassium chloride. Here, ashes from global straw (rice straw ash, RSA) are characterised (via X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetry) and tested from a reactivity point of view (reaction towards calcium hydroxide) in order to assess the possibility for its reuse in cementing systems. Results from pastes made by mixing RSA and calcium hydroxide showed that the pozzolanic reactivity of the ashes is important (hydrated lime fixation of 82% for 7 days and 87% for 28 days in RSA:hydrated lime paste) and cementing C S H gel is formed after 7 and 28 days at room temperature. Compressive strength development of Portland cement mortars with 10% and 25% replacements by RSA yielded 107% and 98% of the strength of control mortar after 28 days of curing. Frattini test confirmed the pozzolanicity o

[EN] Aloe vera gel, analysed as to its antifungal properties against six fungi causing plant diseases, was found to be most effective against Fusarium oxysporum. It was included in different ratios in starch based films plastiziced with glycerol to obtain antifungal films. These were characterized as to their physical (barrier and optical) and structural properties. Films containing the highest ratio of Aloe vera solids (1:1, with respect to starch) and different glycerol mass ratios with respect to starch (0.15 and 0.25) were analysed as to the water sorption and water plasticization effects, in order to discover the water sensitivity of the films in different RH ambients. Films with 0.15 g glycerol/g starch were more homogenous, with a lower degree of starch crystallization, reduced water vapour permeability and higher gloss and transparency. These films with the highest Aloe vera ratio were effective at controlling fungal decay and weight loss in cherry tomatoes. (C) 2017 Elsevier Ltd. All rights reserved.

[EN] The precise boundary delineations between taxa in symbiotic associations are very important for evolutionary and ecophysiological studies. Growing evidence indicates that in many cases, the use of either morphological characters or molecular markers results in diversity underestimation. In lichen symbioses. Trebouxia is the most common genus of lichen phycobionts, however, the diversity within this genus has been poorly studied and as such there is no clear species concept. This study constitutes a multifaceted approach incorporating aspects of ultrastructural characterization by TEM and phylogenomics to evaluate the morphological and genetic diversity of phycobionts within the sexually reproducing lichen Ramalina fraxinea in the context of Mediterranean and temperate populations. Results reveal an association with at least seven different Trebouxia lineages belonging to at least two species. T. decolorans and T. jamesii, and diverse combinations of such lineages coexisting within the same thallus depending on the analysed sample. Some of these lineages are shared by several other non-related lichen taxa. Our findings indicate the existence of a highly diverse assemblage of Trebouxia algae associating with R. fraxinea and suggest a possible incipient speciation within T. decolorans rendering a number of lineages or even actual species. This study stresses the importance of coordinated ultrastructural and molecular analyses to improve estimates of diversity and reveal the coexistence of more than one Trebouxia species within the same thallus. lt is also necessary to have clearer species delimitation criteria within the genus Trebouxia and microalgae in general.

[EN] The antimicrobial activity of essential oils (EO) is very well-known and it has been reported that incorporating them into edible films based on biopolymers extends the food's shelf-life. In this study, cinnamon, clove and oregano EO, at 25% with respect to the polymer, were incorporated into glycerol plasticized starch-gelatin blend films (ratio 1:1) in order to elucidate their effect on the physical (barrier, mechanical and optical), structural and antifungal properties of the films. Whereas EOs exhibited no significant effect on tensile behavior in the case of casting films conditioned at 53% relative humidity and 25 degrees C, the EO compounds did significantly reduce the water vapor and oxygen permeability of the films. Likewise, the EOs increased the films' transparency but reduced their gloss. Despite the fact that about 60% of the incorporated EOs were lost during the film drying step, they exhibited antifungal activity against the two tested fungal species, Colletotrichum gloesporoides (CG) and Fusarium oxysporum (FOG), as revealed by the in vitro agar diffusion method. (C) 2016 Elsevier Ltd. All rights reserved.

[EN] Endophytes from wheat cultivars isolated in Buenos Aires province, Argentina, were assessed for their potential as biocontrol agents against Pyrenophora tritici-repentis (Died.) Drechsler (anamorph Drechslera tritici-repentis) (Died.) Shoem (Dtr), the causal agent of tan spot of wheat. Endophytes were screened using dual culture techniques and examining the effect on growth, sporulation and the antifungal activity in greenhouse assays. The most of endophytes tested significantly reduced Dtr growth compared to the control except Rhodotorula rubra from 11 to 15 days post inoculation. Trichoderma hamatum, Penicillium sp., Bacillus sp. and Paecilomyces lilacinus significantly reduced the colony diameter of the pathogen. Most of the endophytes evaluated showed morphological changes in the conidia and/or the mycelia of D. tritici-repentis. In addition, two endophytes, Bacillus sp. and Fusarium sp., reduced significantly the percent spore germination of Dtr compared to the control by 82% and 52% respectively. In greenhouse experiment T. hamatum, Chaetomium globosum and Fusarium sp. significantly (P <= 0.05) reduced the average disease severity on all three leaves compared to the control. However, the best antagonistic effect was shown with T. hamatum as it resulted in the greatest suppression in the greenhouse and in the dual-plate assays. Likewise, Bacillus sp. was other highlighted microorganism that antagonized the pathogen in in vitro assays. From our promising results, we conclude that endophytes have potential in the biological control of tan spot of wheat caused by D. tritici-repentis, particularly T. hamatum and Bacillus sp. (C) 2015 Elsevier Inc. All rights reserved.

[EN] Recently, biochars and hydrochars have been proposed as soil amendments and, to a lesser degree, as substrate constituents for soilless cultivation. These materials are interesting because their use is a means to reclaim organic matter and because, in some instances, they have been proved to sequester CO2 from the atmosphere. Myrtle and mastic are native to Mediterranean ecosystems and are grown for their essential oil production. This study aims to assess the properties of two biochars from different feedstock and a hydrochar from the same feedstock as one of the biochars as substrate constituents, in order to partially substitute either coir or soil in the cultivation of myrtle and mastic. Although the physical properties of the four organic materials are reasonably adequate for their use in substrate mixes, the biochar of olive mill waste is extremely saline as a pure material and remains very saline in a 50% mix with coir. The hydrochar showed less easily available water for the plants and a lower pH than the others. In incubation experiments using mixes with soil, biochars absorbed more 02 than CO2 emitted, which suggests they were sequestering CO2. The hydrochar showed O-2 consumption and CO2 emission of one order of magnitude larger than the biochars. It also showed that an outstanding amount of organic carbon was being metabolized in anaerobic routes. The biochar of forest waste and the coir displayed N immobilization when mixed with soil, whilst the biochar of olive mill waste had little microbial activity. Although hydrochars had been proved not to immobilize N as pure materials, they did immobilize N when mixed with soil. When tried for plant growth, mixes of the local soil with the biochar of forest waste and with hydrochar produced the best mastic plants. However, unmixed soil gave the best results for myrtle. The biochar of olive mill waste proved phytotoxic for myrtle in mixes with coir, whilst the biochar of forest waste gave optimal results for

[EN] Rice is exposed in the field and in stored conditions to a great variety of fungi that can cause a lot of diseases with potential risk to consumers. In the present study, the chemical composition of commercial Laurus nobilis L. and Syzygium aromaticum L. Merr. & Perry essential oils and antifungal activity against five pathogenic fungi isolated from Mediterranean rice grains has been investigated. Thirty-seven compounds accounting for more than 99.5% of the total essential oil were identified by GC and GC/MS. 1,8-Cineole (51.95%), alpha-terpinyl acetate (12.93%) and the monoterpene hydrocarbon sabinene (9.56%) were the main compounds in bay leaf essential oil, while the phenylpropanoid eugenol (88.58%), and the sesquiterpene hydrocarbons beta-caryophyllene (8.13%) and alpha-humulene (2.35%) were found in clove essential oil. Clove essential oils at 300 mu g/mL showed more antifungal effect than bay leaf essential oil against all tested strains. S. aromaticum essential oil showed the best antifungal activity towards Fusarium graminearum and similar antifungal activity compared to pure eugenol against all tested phytopathogenic fungi. In inoculated rice grain, clove essential oil significantly reduced the fungal infection in food so S. aromaticum essential oil could be a good alternative as preservative in stored rice grain. (C) 2015 Elsevier Ltd. All rights reserved.

[EN] Two biochars, one from forest waste (BCH-FW) and the other from olive mill waste (BCH-OMW), and one hydrochar from forest waste (HYD-FW) were analyzed from the horticultural and environmental point of view. Several incubation assays were performed to foresee the material evolution when used as soilless growth media. HYD-FW was slightly alkaline and rich in nutrients and showed high microbial respiration Moreover, it did not caused N immobilization but N mineralization which contradicts previous reports. Biochars were highly alkaline. BCH-FW was poor in nutrients whilst BCH-OMW was saline and rich in soluble cations. Both materials had low respiratory activity, similar to that of coir fibre (CF). Whilst BCH-FVV and CF immobilize N, BCH-OMW did not. Both biochars captured CO2 from the atmosphere, particularly BCH-OMW, which concomitantly showed a decrease in soluble cations. We conclude that pure hydrochar does not immobilize N and that alkaline biochars act as CO2 traps. (C) 2014 Elsevier Ltd. All rights reserved.

[EN] Peat replacement is an issue that receives much attention in the horticulturist agenda. Several organic materials have been suggested either as substrates or as substrate constituents. This study aims to determine how three such materials, one compost and two vermicomposts, affect the rooting of cuttings and plant growth of rosemary plants grown in pots. The compost (C) and vermicomposts (V1 and V2) were obtained from the same batch of tomato crop waste. Each material was mixed with peat at several proportions. Two experiments were carried out in nursery conditions. In the first, rosemary cuttings were grown in each mix and rooting was quantified. In the second experiment, rooted seedlings were grown in each mix to marketable size (six months after the seedling transplant). The physical, physico-chemical and chemical characteristics of the initial mixes and of the mixes at the end of the six-month experiment were determined. The physical properties of the substrates were within adequate ranges. pH was fairly alkaline, especially in C and salinity was particularly high in the C-based mixes. Soluble mineral contents in C were much higher than in V1, V2 or peat. Mixing with peat produced substrates with intermediate characteristics. Both vermicomposts outperformed compost and peat for rooting cuttings. The presence of hormone-like substances in the vermicomposts might be behind this effect. The vermicompost-based substrates gave acceptable results for growing plants, though none performed as well as the control. Nitrogen and potassium contents in cuttings and ready-for-sale plants were low and phosphorus content was very low compared to sufficiency ranges, which led to a recommendation to increase fertilization. At the end of the six-month experiment, the mix properties had changed, representing an improvement in the substrate quality that might be taken into consideration when transplanting the rosemary to the soil. (C) 2014 Elsevier B.V. All rights reserved.

Composition of essential oils of different populations of Thymus richardii grex of six localities from Bosnia-Herzegovina (Konjic, Borci), Spain (Majorca, Ibiza, Valencia) and Italy (Marettimo, Sicily) were determined by GC/FID and GC/MS. The main constituents in most of the samples were aromatic monoterpenes corresponding to non-phenolic cyclic compounds (p-cymene, gamma-terpinene). The highest monoterpene concentrations were found in the Bosnian samples (70%), and the lowest in samples from the Balearic Islands (<30%; Ibiza and Majorca). Sesquiterpenes were the major component (average > 50%) in samples from Majorca with beta-bisabolene (>40%) being the principal constituent. Discriminant analysis (LDA) shows the differentiation of two chemotypes: A (phenol chemotype), with p-cymene and gamma-terpinene as characteristic compounds and B, with beta-bisabolene and carvacrol, as major and significative compounds. The occurrence of the chemotypes was related to summer positive precipitation and to deep of soils.

[EN] The fruit is the main sink organ in Citrus and captures almost all available photoassimilates during its development. Consequently, carbohydrate partitioning and starch content depend on the crop load of Citrus trees. Nevertheless, little is known about the mechanisms controlling the starch metabolism at the tree level in relation to presence of fruit. The aim of this study was to find the relation between the seasonal variation of expression and activity of the genes involved in carbon metabolism and the partition and allocation of carbohydrates in 'Salustiana' sweet orange trees with different crop loads. Metabolisable carbohydrates, and the expression and activity of the enzymes involved in sucrose and starch metabolism, including sucrose transport, were determined during the year in the roots and leaves of 40-year-old trees bearing heavy crop loads ('on' trees) and trees with almost no fruits ('off' trees). Fruit altered photoassimilate partitioning in trees. Sucrose content tended to be constant in roots and leaves, and surplus fixed carbon is channeled to starch production. Differences between 'on' and 'off' trees in starch content can be explained by differences in ADP-glucose pyrophosphorylase (AGPP) expression/activity and alpha-amylase activity which varies depending on crop load. The observed relation of AGPP and UGPP (UDP-glucose pyrophosphorylase) is noteworthy and indicates a direct link between sucrose and starch synthesis. Furthermore, different roles for sucrose transporter SUT1 and SUT2 have been proposed. Variation in soluble sugars content cannot explain the differences in gene expression between the 'on' and 'off' trees. A still unknown signal from fruit should be responsible for this control.

Organic pollutants effects on lichens have not been addressed. Rehydration is critical for lichens, a burst of free radicals involving NO occurs. Repeated dehydrations with organic pollutants could increase oxidative damage. Our aim is to learn the effects of cumene hydroperoxide (CP) during lichen rehydration using Ramalina farinacea (L.) Ach., its photobiont Trebouxia spp. and Asterochloris erici. Confocal imaging shows intracellular ROS and NO production within myco and phycobionts, being the chloroplast the main source of free radicals. CP increases ROS, NO and lipid peroxidation and reduces chlorophyll autofluorescence, although photosynthesis remains unaffected. Concomitant NO inhibition provokes a generalized increase of ROS and a decrease in photosynthesis. Our results suggest that CP induces a ompensatory hormetic response in Ramalina farinacea that could reduce the lichen s antioxidant resources after repeated desiccation-rehydration cycles. NO is important in the protection from CP.

Saffron is a triploid sterile crop with a low vegetative propagation rate, which prevents the widespread use of selected genotypes. Despite efficient in vitro propagation via direct organogenesis being very interesting, high contamination levels and low propagation rates preclude the commercial use of this technique. In order to obtain a source of explants for the in vitro multiplication of saffron that allows low contamination levels and efficient propagation, daughter corms were produced by storing non-planted mother corms at low temperatures (1-3 degrees C) for 9 months. This method avoids field cultivation and yields more corms than field production (8 vs. 3 corms per mother corm). Corms produced under cold storage conditions were in vitro sprouted on media with a high level of cytokinins (5 mg l(-1) 6-benzylaminopurine or 1 mg l(-1) thidiazuron) and 0.5 mg l(-1) naphthalene acetic acid, and sprouted buds were cultivated on the same media. After 8 weeks of culture, multiple shoot primordia emerged from the base of the sprouted buds with no callus formation, and up to 400 shoot primordia were produced from one initial mother corm. These shoot primordia can be elongated and 90% produce corms. The high multiplication rate, lack of contamination, and the fact that multiplication occurs through direct organogenesis make the method suitable for the propagation of selected genotypes. Otherwise shoot clusters can be maintained for 6-7 months. However for longer maintenance periods, shoot proliferation capacity by direct organogenesis diminishes, and the emergence of somaclonal variation cannot be ruled out.

[EN] The objective of this work was to study the influence of fruit load on CO2 assimilation in the leaves of citrus trees presenting alternate bearing habits, and the importance of this factor on photosynthetic rate variability throughout the year and under regular cropping conditions. The photosynthetic rate was measured on 60 days throughout the year on field-grown sweet orange plants under natural conditions in the Valencian Community, the most important citrus-producing area of Spain. The experiments were performed on the 'on' (high crop) and 'off' (low crop) bearing 40-year-old Salustiana sweet orange trees growing in the same orchard. Gas exchange and fluorescence parameters were measured during the year in young and old leaves on sun-exposed branches with and without fruit in the 'on' trees, and in fruitless branches of the 'off' trees. In non-manipulated Citrus trees, fruit load has no significant effect in any season on the photosynthetic rate in the leaves from branches without fruit. However, in high crop trees, the leaves of branches bearing fruit present a slightly lower photosynthetic rates (approx. 10%) than those of fruitless branches. Variations in mineral content (N, K and P) might explain not only these differences, but also the lower photosynthesis rate observed in old leaves (13-24 month-old leaves). Environmental conditions were the main factor for the variation of the photosynthetic rate, with variability of the monthly mean photosynthetic rate being much lower than that between days in the same month.

[EN] Changes in physical and chemical characteristics of an organic waste (tomato crop waste) throughout composting (COM), vermicomposting (VER) and the combination of both processes (C + V) were assessed at five selected stages. COM consisted of a combination of the static Rutgers system with forced aeration and pile turning. For VER Eisenia worms were fed with the raw material. For C + V pre-composted material was added to the worms. Particle size decreased during COM, yet it increased during VER and C + V due to the amalgamation of small particles. pH was alkaline throughout the processes. Heavy irrigation during vermicomposting resulted in greater decrease of EC and greater leaching of organic matter, total nitrogen and most macronutrients in VER and C + V than in COM. Final materials were not phytotoxic but compost could have salinity related problems. Thus, COM, VER and C + V produced treated organic material, which could be suitable for horticultural purposes. (C) 2012 Elsevier Ltd. All rights reserved.

The search for new biocontrol strategies to inhibit the growth of phytopathogenic microorganisms has become widely widespread due to environmental concerns. Among actinomycetes, Streptomyces species have been extensively studied since they have been recognized as important sources of antibiotics. Actinomycete strains were isolated from a calcareous soil, 2 two-phase olive mill waste ('alperujo') composts, and the compost-amended soil by using selective media, and they were then co-cultured with 5 phytopathogenic fungi and 1 bacterium to perform an in vitro antagonism assay. Forty-nine actinomycete strains were isolated, 12 of them showing a great antagonistic activity towards the phytopathogenic microorganisms tested. Isolated strains were identified by 16S rDNA sequence analysis and phenotypic procedures. Eleven isolates concerned the genus Streptomyces and 1 actinomycete with chitinolytic activity belonged to the genus Lechevalieria. © 2010 Elsevier Ltd.

Lichen thalli are permeable to airborne substances, including heavy metals, which are harmful to cell metabolism. Ramalina farinacea shows a moderate tolerance to Pb. This lichen comprises two Trebouxia phycobionts, provisionally referred to as TR1 and TR9, with distinct physiological responses to acute oxidative stress. Thus, there is a more severe decay in photosynthesis and photosynthetic pigments in TR1 than in TR9. Similarly, under oxidative stress, antioxidant enzymes and HSP70 protein decrease in TR1 but increase in TR9. Since Pb toxicity is associated with increased ROS formation, we hypothesized greater Pb tolerance in this phycobiont. Accordingly, the aim of the present study was to characterize the physiological differences in the responses of TR1 and TR9 to Pb exposure. Liquid cultures of isolated phycobionts were incubated for 7 days in the presence of Pb(NO3)2. Thereafter, extracellular and intracellular Pb accumulation, photosynthetic pigments, and photosynthesis (as modulated chlorophyll fluorescence) were analyzed along with the antioxidant enzymes glutathione reductase (GR), superoxide dismutase (SOD), ascorbate peroxidase (APx), and catalase (CAT), and the stress-related protein HSP70. Pb uptake increased with the amount of supplied Pb in both algae. However, while significantly more metal was immobilized extracellularly by TR9, the amount of intracellular Pb accumulation was three times higher in TR1. In neither of the phycobionts were significant effects on photosynthetic pigments or photosynthetic electron transport observed. While under control conditions GR, SOD, and APx levels were significantly higher in TR1 than in TR9, only in the latter were these enzymes induced by Pb. This resulted in quantitatively similar antioxidant activities in the two algae when exposed to Pb. In conclusion, the phycobionts of R. farinacea make use of two different strategies against stress, in which the integration of distinct anatomical and physiological featur

A major constraint limiting saffron cultivation is the difficulty of obtaining high quality corms for propagation. There is limited knowledge about the physiology of vegetative development of saffron. The aim of this work was to analyse the relative contribution of different carbon sources (leaf photosynthetic activity and mother corm reserves) to the growth of vegetative organs and to analyse the influence of internal and external factors on the photosynthetic processes sustaining corm growth. The photosynthetic rate and changes in biomass were measured over the course of the vegetative growing season. The influence of the size of the mother corm, the cultivation method used (greenhouse versus field) and water availability on saffron production was assessed. Most of the remaining mother corm reserves after flowering were depleted during root and leaf development. After these organs reached their maximum size, the growth of replacement corms was initiated, and this development primarily relied on photosynthesis. Saffron mother corm reserves only contributed 10% to the biomass during vegetative development. The photosynthetic rate was consistently very high (26 mu mol m(-2) s(-1)) throughout the year but was reduced in plants from the largest corms. A sink capacity limitation arose during growth of replacement corms since the increase of biomass was limited before total leaf senescence. Saffron grown under greenhouse conditions exhibited traits characteristic of plants grown under low-irradiance, even after the saffron plants were transferred to the field. This fact limits the production of replacement corms in this environment. A decrease in the photosynthetic rate was observed under water stress, but the supply of water to the leaves from the corms and roots was found to maintain a still high photosynthetic rate (12 mu mol m(-2) s(-1)) even at highly negative soil water potentials.

Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD1.6) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels. © 2010 Elsevier Ltd. All rights reserved.

Ozone effects on the perennial forb Lamottea dianae were studied in an open-top chamber experiment. Ozone was found to induce reductions in CO 2 assimilation and water use efficiency in the leaves of this species. These reductions were mainly related to a decline in the in vivo CO 2 fixation capacity of Rubisco (V c,max), rather than to stomatal limitations or photoinhibitory damage (F v:F m). In addition to chloroplast degeneration, other observed effects were callose accumulation, formation of pectinaceous wart-like cell wall exudates and phloem alterations. Moreover, ozone exposure significantly reduced root dry biomass. The possible relevance of these adverse effects for Mediterranean forbs is commented. These results show that endemic plants can be very sensitive to ozone, suggesting that risks associated with this pollutant should be taken into account for conservation purposes. © 2011 Elsevier Inc.

[EN] The aim of this work was to assess the relation between carbohydrate levels and flower and fruit production, as well as the role of carbohydrates on CO(2) fixation activity, by analysis of leaves, twigs and roots from the alternate bearing 'Salustiana' cultivar of sweet orange (Citrus sinensis [L.] Osbeck). A heavy crop load (on year) did not affect photosynthesis activity when compared to non-fruiting trees (off year). Fruiting trees accumulated most of the fixed carbon in mature fruits, whilst no accumulation was observed in roots before harvest. Non-fruiting trees transported part of the fixed carbon to the roots and mobilize it for growth processes and, at the end of the season (December), store it as reserves. Reserve carbohydrates accumulation in leaves started by early December for both tree types, showing the same levels in on and off trees until spring bud sprouting. A heavy flowering after an off year caused the rapid mobilization of the stored reserves, which were exhausted at full bloom. We found no evidence on carbon fixation regulation by either fruit demand or carbohydrate levels in leaves. Carbohydrate reserves played little or no role over fruit set, which actually relied on current photosynthesis

[EN] The effect of ethylene (2 mu L L(-1)) on total and soft epicuticular wax content and wax morphology has been investigated in mature 'Navelate' (Citrus sinensis, L. Osbeck) oranges held under non-stressful environmental conditions (22 degrees C and constant high relative humidity (90-95% RH)). In addition, the objective of the study was to understand whether the ethylene-induced changes in epicuticular wax might participate in the beneficial effect of ethylene reducing non-chilling peel pitting, by modifying peel water, osmotic or turgor potential, or disease incidence caused by Penicillium digitatum (Pets.:Fr.) Sacc. Ethylene increased total and soft epicuticular wax content in 'Navelate' fruit and induced structural changes in surface wax that might be related to the formation of new waxes. Changes in epicuticular wax morphology, but not in its content, might be involved in the protective role of ethylene reducing non-chilling peel pitting, although the beneficial effect of the hormone is not related to water stress. Cell water and turgor potentials in freshly harvested fruit and fruit stored in air under non-stressful conditions suggest that water stress is not a limiting factor leading to the development of this physiological disorder. In addition, the results indicated that formation of new waxes in fruit treated with ethylene may partially cover stomata, cracks or areas lacking wax occurring in stored fruit and is likely to improve physical barriers to P. digitatum penetration. (C) 2009 Elsevier B.V. All rights reserved.

[EN] An open-top chamber study was conducted to investigate the tissue and cellular-level foliar effects of ozone (O-3) on a Mediterranean evergreen species, the mastic plant (Pistacia lentiscus L.). Plants were exposed at three different O-3 levels, and leaf samples were collected periodically from the beginning of the exposure. Although no visible foliar injury was evident, alterations of the plastids and vacuoles in the mesophyll were observed. Senescence processes were accelerated with an anomalous stacking of tannin vacuoles, and a reduction in the size and number of the chloroplasts. Overall, most of the modifications induced by O-3 were consistent with previously reported observations on deciduous broadleaf species, with the exception of alterations in the cells covering the secretory channels, reported here as a new finding. Comments on the feasibility of using microscopy to validate O-3 related field observations and subtle foliar injury are also given. (C) 2004 Elsevier Ltd. All rights reserved.

[EN] Yield and fruit characteristics of grafted plants of the 'Reina de Corazones' watermelon cultivar (Citrullus lanatus (Thunb.) Matsum and Nakai), grown in Fusarium-infestated soils, were determined in a series of experiments performed in the 8-year period 1993-2000. The experiments were performed in the coastal area south Valencia, Spain, in soils with a clay content ranging from 16 to 38%. Plant survival and yield were the highest in plants grafted onto several Cucurbita maxima x Cucurbita moschata hybrids and onto 'Jover' and 'Bodi 1' C. moschata cultivars. The survival ratio of the plants grafted onto 'Shintoza' rootstock (C. maxima x C moschata) was 93%, while the mean yield in an early production cycle with harvests extending from the end of June to mid-August was 89,000 kg ha(-1). The 'Shintoza' rootstock increased fruit size compared to the non-grafted plants, and improved yield stability by decreasing the coefficient of variation to 20%. The use of 'Shintoza' rootstock had no effect on the soluble solids concentration of the central endocarp, and did not increase the development of yellowish bands in the flesh or the internal breakdown of the endocarp. The use of this rootstock is an advantageous alternative to soil fumigation by methyl bromide for the control of Fusarium, wilt in watermelon production, as it is cheaper and safer, and the yields are higher and more reliable. (C) 2004 Elsevier B.V. All rights reserved.

[EN] Two chitinases induced in tomato leaves (Lycopersicon esculentum Mill cv. Rutgers) by citrus exocortis viroid (CEV) infection were purified. Their molecular masses determined by sodium dodecyl sulfate-gel electrophoresis were 32 kDa and 34 kDa and by filtration through Sephadex G-100 were 23 kDa and 25 kDa, respectively. These chitinases (P32 and P34) have been shown to be identical to the tomato pathogenesis-related proteins C7 and C6. They were purified in three stages: ammonium sulphate fractionation, chitin affinity chromatography and CM-Sepharose chromatography. The characterization of P32, the major component of the CEV-induced chitinase activity, revealed a basic protein (pI, 8·5), with a low optimum pH of 5·2 for hydrolytic activity, a high thermal stability and resistance to proteolytic degradation. These tomato chitinases have been shown to be serologically related to the tobacco chitinases. Our results lend further support to the hypothesis that enhanced chitinase activity is a component of a general mechanism of response to pathogens and other stress agents.