Biochemical Analysis of a Castor Bean Leaf Extract and its Insecticidal Effects Against Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae)

Plant extracts represent a great source of molecules, with insecticidal activity, which are used for pest control in several crop production systems. This work aimed to evaluate the toxicity of an aqueous extract of leaves of castor bean against larvae of Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) in search for different classes of molecules with insecticidal activities by using in vitro assays. The effects of the castor bean leaf extract on the food utilization, development, and survival of S. frugiperda larvae was evaluated by feeding the larvae an artificial diet supplemented with different concentrations of the extract (0%, 1%, 2.5%, 5%, and 10% w/v). The effects observed were dose-dependent, and the highest concentration evaluated (10% w/v) was the one the most affected food utilization by altering the nutritional indices, as well as larval weight gain, development time, and survivorship. In vitro assays to detect saponins, lectins, and trypsin inhibitors in the castor bean leaf extract were performed, but only trypsin inhibitors were detected. No preference for the diet source was detected in S. frugiperda by feeding the larvae in choice experiments with diets containing different concentrations of the castor bean extract tested. The data obtained indicate the existence of a potential molecule in the tested extract of castor bean to be used as an alternative insecticide to be integrated in the management of S. frugiperda.

Impact of Aqueous Plant Extracts on Trigona spinipes (Hymenoptera: Apidae)

The stingless bees are an important component of the insect biomass in many tropical areas, due to their collection of nectar and pollen. Trigona spinipes is a widely distributed species in South America, and described as a pollinator of many crops that can be used in a commercial pollinating system. The effects of plant extracts on insects are studied because of the demand for organic food and their selectivity to natural enemies. Plant insecticides are reported as a potential agent for the control of insect pests, however little is known about their impact on beneficial insects. This study investigated the survival of Trigona spinipes (Hymenoptera: Apidae, Meliponini) Fabricius, after exposure to the leaf extracts of Azadiracha indica (Meliaceae), Lippia sidoides (Verbenaceae), Sapindus saponaria (Sapindaceae), Anonna squamosa (Anonnaceae) Cymbopogon winterianum (Poaceae), Corimbia citriodora (Myrtaceae), Jatropha curcas (Euphorbiaceae) and Ricinus communis (Euphorbiaceae) and of seeds of Azadiracha indica, Ricinus communis Nordestina and AL Guarany varieties and Jatropha curcas. The extracts that had the greatest influence on the survival of the bees were A. indica at 3% and 7% of concentration, A. squamosa at a concentration of 10% with 68.89% survival and green leaf of R. communis at a concentration of 7%. The results show that although the extracts were effective in controlling pests, they may also affect the pollinator Trigona spinipes.

EVALUATION OF THE PERFORMANCE OF A CASTOR-OIL BASED FORMULATION IN LIMITING PESTICIDE RESIDUES IN STRAWBERRY CROPS

A study was made to evaluate the effect of a castor oil-based detergent on strawberry crops treated with different classes of pesticides, namely deltamethrin, folpet, tebuconazole, abamectin and mancozeb, in a controlled environment. Experimental crops of greenhouse strawberries were cultivated in five different ways with control groups using pesticides and castor oil-based detergent. The results showed that the group 2, which was treated with castor oil-based detergent, presented the lowest amount of pesticide residues and the highest quality of fruit produced.

Immediate and long-term effects of polysaccharides-based formulations on human skin

A new trend in cosmetic formulations is the use of biotechnological raw materials as the polysaccharides from Klebsiella pneumoniae, which are supposed to enhance cell renewal, improve skin hydration and micro-relief. Botanical extracts of Myrtus communis leaves contain different sugars, which may provide the same benefits. Thus, the objective of this study was to evaluate through objective and subjective analysis the immediate and long-term effects of cosmetic formulations containing polysaccharides biotechnologically-originated and / or the ones contained in Myrtus communis extracts. Three polysaccharide-based and placebo formulations were applied on the forearm skin of 40 volunteers. Skin hydration, transepidermal water loss (TEWL), viscoelasticity and skin micro-relief measurements were made before and 2 hours after a single application and after 15 and 30 day-periods of daily applications. Answers to a questionnaire about perceptions of formulation cosmetic features constituted the subjective analysis. All polysaccharide-based formulations enhanced skin hydration. Formulations with isolated or combined active substances improved skin barrier function as compared to placebo, in the short and long term studies. Formulations containing Myrtus communis extracts had the highest acceptance. Results suggest that daily use of formulations containing these substances is important for protection of the skin barrier function.

DEVELOPMENT OF MICROSATELLITE PRIMERS FOR JATROPHA CURCAS (EUPHORBIACEAE) AND TRANSFERABILITY TO CONGENERS

Premise of the study: Microsatellite primers were developed for Jatropha curcas (Euphorbiaceae), a tree species with large potential for biofuel production, to investigate its natural genetic diversity and mating system to facilitate the establishment of tree improvement and conservation programs. Methods and Results: Using a protocol for genomic library enrichment, 104 clones containing 195 repeat motifs were identified. Primer pairs were developed for 40 microsatellite loci and validated in 41 accessions of J. curcas from six provenances. Nine loci were polymorphic revealing from two to eight alleles per locus, and six primers were able to amplify alleles in the congeners J. podagrica, J. pohliana, and J. gossypifolia, but not in other Euphorbiaceae species, such as Hevea brasiliensis, Manihot esculenta, or Ricinus communis. Conclusions: The primers developed here revealed polymorphic loci that are suitable for genetic diversity and structure, mating system, and gene flow studies in J. curcas, and some congeners.

Yield of two castor bean cultivars under different depths of supplemental irrigation

This study evaluated the yield, components of production and oil content of two castor bean cultivars through drip irrigation with different water depths. The research was conducted in 2009 in an Oxisol clay in the experimental field in Dourados, Mato Grosso do Sul State. The experimental design was randomized blocks in factorial scheme with five water depths (0, 25, 50, 100 and 150% of evapotranspiration for drip irrigation) in two castor bean cultivars (IAC 2028 and IAC 80) with four replications. The irrigation schedule was predetermined up to two irrigations per week except on rainy days. The increase of irrigation provided significant increase in most components of production and crop yield without changing the oil content of seeds. The application of higher water depth increased yield by 80% in relation to the treatment that received no supplemental irrigation.

Distribuição do nervo ibular comum em fetos de equinos e descrição anatômica de pontos para bloqueio anestésico

Analisou-se a distribuição do nervo fibular comum em 30 fetos de equinos, sem raça definida, provenientes do acervo do Laboratório de Anatomia Animal da Faculdade de Medicina Veterinária da Universidade Federal de Uberlândia, que foram injetados e conservados em solução aquosa de formaldeído a 10%. Contatou-se que o referido nervo deriva do isquiático, divide-se em nervos fibulares superficial e profundo, distribuindo-se para os músculos extensores lateral e longo do dedo, fibular terceiro e tibial cranial. Traçando-se uma linha imaginária na região médio-lateral da tuberosidade do osso tíbia, o nervo fibular comum pode ser bloqueado em sua parte proximal, no terço caudal, entre o tendão de inserção do músculo bíceps femoral e a face lateral do músculo gastrocnêmio lateral (terço médio); e o nervo fibular profundo, na parte proximal da tíbia, crânio-distalmente ao fibular comum. O bloqueio do nervo fibular superficial pode ser realizado em duas regiões da tíbia: na proximal, considerando-se a linha imaginária, distalmente ao ponto citado para o fibular comum e caudalmente ao descrito para o fibular profundo; e na distal, na face lateral da articulação tíbio-társica, entre os tendões de inserção dos músculos extensores lateral e longo do dedo.

OPTIMUM RATIO OF CALCIUM AND BORON IN THE NUTRIENT SOLUTION OR IN CASTOR BEAN SHOOT FOR FRUIT YIELD AND SEED OIL CONTENT

Calcium (Ca) and boron (B) have been reported as the major macro-and micronutrient required for castor bean plant yield. The objective of this study was to determine the Ca: B ratios (in the growth media and plant tissue) for fruit yield and shoot dry weight of the castor bean (Ricinus communis L.), grown in a nutrient solution, and to evaluate Ca and B supply on concentration and total uptake of Ca, potassium (K), magnesium (Mg), and B, as well on the seed oil content. The treatments were arranged in a 3 x 3 factorial fashion, consisting of three rates of Ca (40, 80, and 160 mg L-1) and three of B (0.32, 0.96, and 1.60 mg L-1). Calcium and B rates increased the shoot and root dry weight and fruit yield at a Ca: B ratio in the nutrient solution of 166 and 100, respectively. Symptoms of B deficiency were observed in plants supplied with 0.32 mg B L-1, regardless of the Ca concentration in the nutrient solution. Plants which showed visual symptoms of Ca deficiency cultivated with 40 mg Ca L-1 presented concentration of Ca in plant tissue up to 10 g kg(-1). The concentration and total Ca and B uptake increased with the rates of them. Notwithstanding, the shoot Ca accumulation was improved by B rates. In addition, there were no decreases in K and Mg uptake due to Ca rates. Furthermore, addition of 80 mg L-1 of Ca and 1.60 mg L-1 of B in the growth media increased the seed oil content. The Ca: B ratio in the diagnostic leaf associated with the highest plant dry weight (shoot and root) and fruit yield, was 500 (16 to 20 g kg(-1) of Ca, and for 30 to 40 mg kg(-1) of B).

Diametral tensile strength and film thickness of an experimental dental luting agent derived from castor oil

The need to develop new dental luting agents in order to improve the success of treatments has greatly motivated research. Objective: The aim of this study was to evaluate the diametral tensile strength (DTS) and film thickness (FT) of an experimental dental luting agent derived from castor oil (COP) with or without addition of different quantities of filler (calcium carbonate - CaCO3). Material and Methods: Eighty specimens were manufactured (DTS N=40; FT N=40) and divided into 4 groups: Pure COP; COP 10%; COP 50% and zinc phosphate (control). The cements were mixed according to the manufacturers' recommendations and submitted to the tests. The DTS test was performed in the MTS 810 testing machine (10 KN, 0.5 mm/min). For FT test, the cements were sandwiched between two glass plates (2 cm(2)) and a load of 15 kg was applied vertically on the top of the specimen for 10 min. The data were analyzed by means of one-way ANOVA and Tukey's test (alpha=0.05). Results: The values of DTS (MPa) were: Pure COP- 10.94 +/- 1.30; COP 10%- 30.06 +/- 0.64; COP 50%- 29.87 +/- 0.27; zinc phosphate- 4.88 +/- 0.96. The values of FT (pm) were: Pure COP- 31.09 +/- 3.16; COP 10%- 17.05 +/- 4.83; COP 50%- 13.03 +/- 4.83; Zinc Phosphate- 20.00 +/- 0.12. One-way ANOVA showed statistically significant differences among the groups (DTS - p=1.01E-40; FT - p=2.4E-10). Conclusion: The experimental dental luting agent with 50% of filler showed the best diametral tensile strength and film thickness.

Deficiency symptoms and uptake of micronutrients by castor bean grown in nutrient solution

Castor bean is a nutrient-demanding species, but there is still little information on its micronutrient requirements. The objectives of this study were to evaluate the effects of levels of B (2.5, 12.5 and 25.0 µmol L-1), Cu (0.05, 0.25 and 0.50 µmol L-1), Mn (0.2, 1.0 and 2.0 µmol L-1) and Zn (0.2, 1.0 and 2.0 µmol L-1) in a nutrient solution on plant B, Cu, Mn and Zn concentrations and uptake, vegetative growth and fruit yield of castor bean "Iris", grown in greenhouse. The experiment was arranged in a completely randomized block design with three replicates. The first deficiency symptoms were observed for B, followed by Zn, Cu and Mn. The main changes in the cell ultrastructure due to lack of B were thickening of the cell walls and middle lamellae, distorted chloroplasts and tightly stacked thylakoids, besides the absence of starch grains. The Mn, Zn and Cu deficiencies led to disruption of chloroplasts, disintegration of thylakoids and absence of amyloplasts. The concentration and uptake of B, Cu, Mn, and Zn in castor bean plants increased with micronutrient supply in the solution. Fruit yield was drastically reduced by B and Mn deficiencies. On the other hand, the dry matter yield of the shoot and root of castor bean plants was not. In the treatment with full nutrient solution, the leaves accumulated 56 and 48 % of the total B and Mn taken up by the plants, respectively, and the seeds and roots 85 and 61 % of the total Cu and Zn taken up, respectively. This shows the high demand of castor bean Iris for B and Mn for fruit yield.

Evaluation of the performance of a castor-oil based formulation in limiting pesticide residues in strawberry crops

A study was made to evaluate the effect of a castor oil-based detergent on strawberry crops treated with different classes of pesticides, namely deltamethrin, folpet, tebuconazole, abamectin and mancozeb, in a controlled environment. Experimental crops of greenhouse strawberries were cultivated in five different ways with control groups using pesticides and castor oil-based detergent. The results showed that the group 2, which was treated with castor oil-based detergent, presented the lowest amount of pesticide residues and the highest quality of fruit produced.

Teste de raios X na avaliação da qualidade de sementes de mamona

O crescente interesse pelo uso de combustíveis renováveis nos últimos anos fez com que culturas oleaginosas, como a mamona, se tornassem importante objeto de estudo. No entanto, para a instalação de campos desta cultura, é imprescindível o uso de sementes de alta qualidade. O objetivo da pesquisa contida neste trabalho foi verificar a eficiência do teste de raios X na avaliação da qualidade de sementes de mamona após a colheita e armazenamento. Três lotes de sementes da cv. 'IAC-2028' (provenientes, respectivamente, dos racemos primário, secundário e terciário) e dois lotes da cv. 'Guarani' (lotes comerciais com sementes de todos os racemos misturados) foram avaliados de acordo com a morfologia interna pelo teste de raios X, na intensidade de 20 kV por 60 segundos de exposição. Posteriormente, as sementes radiografadas foram submetidas ao teste de germinação de modo a relacionar a morfologia interna das sementes com as respectivas plântulas normais, anormais ou sementes mortas. Após seis meses de armazenamento acondicionadas em sacos de papel Kraft, em condições não controladas de temperatura e umidade relativa do ar, amostras dessas sementes foram novamente avaliadas pelo teste de raios X. O teste de raios X é eficiente para avaliar a morfologia interna das sementes e seus reflexos no potencial fisiológico.

Uso sostenibile dei suoli forestali di ambiente costiero in relazione ai fattori di pressione esistenti

Oggetto di studio del dottorato sono stati i suoli forestali in ambiente litoraneo della Regione Emilia-Romagna. In particolare sono state considerate quattro zone di studio in Provincia di Ravenna: Pineta di San Vitale, aree boscate di Bellocchio, Pineta di Classe e Pineta di Pinarella di Cervia. Lo studio in una prima fase si è articolato nella definizione dello stato del sistema suolo, mediante la caratterizzazione pedologica delle zone di studio. A tale scopo è stata messa a punto un’adeguata metodologia d’indagine costituita da un’indagine ambientale e successivamente da un’indagine pedologica. L’indagine ambientale, mediante fotointerpretazione ed elaborazione di livelli informativi in ambito GIS, ha permesso di individuare ambiti pedogenetici omogenei. L’indagine pedologica in campo ha messo in luce l’elevata variabilità spaziale di alcuni fattori della pedogenesi, in particolar modo l’andamento microtopografico tipico dei sistemi dunali costieri e la profondità della falda freatica del piano campagna. Complessivamente sono stati aperti descritti e campionati 40 profili pedologici. Sugli orizzonti diagnostici di questi sono state eseguite le seguenti analisi: tessitura, pH, calcare totale, carbonio organico, azoto kjeldahl, conduttività elettrica (CE), capacità di scambio cationico (CSC) e calcare attivo. I suoli presentano, ad eccezione della tessitura (generalmente grossolana), un’elevata variabilità delle proprietà chimico fisiche in funzione della morfologia, della profondità e della vicinanza della falda freatica. Sono state riscontrate diverse correlazioni, tra le più significative quelle tra carbonio organico e calcare totale (coeff. di correlazione R = -0.805 per Pineta di Classe) e tra calcare totale e pH (R = 0.736), dalle quali si è compreso in che misura l’effetto della decarbonatazione agisce nei diversi ambiti pedogenetici e tra suoli con diversa età di formazione. Il calcare totale varia da 0 a oltre 400 g.kg-1 e aumenta dalla superficie in profondità, dall’entroterra verso la costa e da nord verso sud. Il carbonio organico, estremamente variabile (0.1 - 107 g.kg-1), è concentrato soprattutto nel primo orizzonte superficiale. Il rapporto C/N (>10 in superficie e molto variabile in profondità) evidenzia una efficienza di umificazione non sempre ottimale specialmente negli orizzonti prossimi alla falda freatica. I tipi di suoli presenti, classificati secondo la Soil Taxonomy, sono risultati essere Mollic/Sodic/Typic Psammaquents nelle zone interdunali, Typic Ustipsamments sulle sommità dunali e Oxiaquic/Aquic Ustipsamments negli ambienti morfologici intermedi. Come sintesi della caratterizzazione pedologica sono state prodotte due carte dei suoli, rispettivamente per Pineta di San Vitale (scala 1:20000) e per le aree boscate di Bellocchio (scala 1:10000), rappresentanti la distribuzione dei pedotipi osservati. In una seconda fase si è focalizzata l’attenzione sugli impatti che le principali pressioni naturali ed antropiche, possono esercitare sul suolo, condizionandone la qualità in virtù delle esigenze del soprasuolo forestale. Si è scelta la zona sud di Pineta San Vitale come area campione per monitorarne mensilmente, su quattro siti rappresentativi, le principali caratteristiche chimico-fisiche dei suoli e delle acque di falda, onde evidenziare possibili correlazioni. Le principali determinazioni svolte sia nel suolo in pasta satura che nelle acque di falda hanno riguardato CE, Ca2+, Mg2+, K+, Na+, Cl-, SO4 2-, HCO3 - e SAR (Sodium Adsorption Ratio). Per ogni sito indagato sono emersi andamenti diversi dei vari parametri lungo i profili, correlabili in diversa misura tra di loro. Si sono osservati forti trend di aumento di CE e degli ioni solubili verso gli orizzonti profondi in profili con acqua di falda più salina (19 – 28 dS.m-1) e profonda (1 – 1.6 m dalla superficie), mentre molto significativi sono apparsi gli accumuli di sali in superficie nei mesi estivi (CE in pasta satura da 17.6 a 28.2 dS.m-1) nei profili con falda a meno di 50 cm dalla superficie. Si è messo successivamente in relazione la CE nel suolo con diversi parametri ambientali più facilmente monitorabili quali profondità e CE di falda, temperatura e precipitazioni, onde trovarne una relazione statistica. Dai dati di tre dei quattro siti monitorati è stato possibile definire tali relazioni con equazioni di regressione lineare a più variabili. Si è cercato poi di estendere l’estrapolabilità della CE del suolo per tutte le altre casistiche possibili di Pineta San Vitale mediante la formulazione di un modello empirico. I dati relativi alla CE nel suolo sia reali che estrapolati dal modello, sono stati messi in relazione con le esigenze di alcune specie forestali presenti nelle zone di studio e con diverso grado di tolleranza alla salinità ed al livello di umidità nel suolo. Da tali confronti è emerso che per alcune specie moderatamente tolleranti la salinità (Pinus pinea, Pinus pinaster e Juniperus communis) le condizioni critiche allo sviluppo e alla sopravvivenza sono da ricondursi, per la maggior parte dei casi, alla falda non abbastanza profonda e non tanto alla salinità che essa trasmette sull’intero profilo del suolo. Per altre specie quali Quercus robur, Populus alba, Fraxinus oxycarpa e Ulmus minor moderatamente sensibili alla salinità, ma abituate a vivere in suoli più umidi, la salinità di una falda troppo prossima alla superficie può ripercuotersi su tutto il profilo e generare condizioni critiche di sviluppo. Nei suoli di Pineta San Vitale sono stati inoltre studiati gli aspetti relativi all’inquinamento da accumulo di alcuni microtossici nei suoli quali Ag, Cd, Ni e Pb. In alcuni punti di rilievo sono stati osservati moderati fattori di arricchimento superficiale per Pb e Cd riconducibili all’attività antropica, mentre le aliquote biodisponibili risultano maggiori in superficie, ma all’interno dei valori medi dei suoli italiani. Lo studio svolto ha permesso di meglio conoscere gli impatti sul suolo, causati dalle principali pressioni esistenti, in un contesto dinamico. In particolare, si è constatato come i suoli delle zone studiate abbiano un effetto tampone piuttosto ridotto sulla mitigazione degli effetti indotti dalle pressioni esterne prese in esame (salinizzazione, sodicizzazione e innalzamento della falda freatica). Questo è dovuto principalmente alla ridotta presenza di scambiatori sulla matrice solida atti a mantenere un equilibrio dinamico con le frazioni solubili. Infine le variabili ambientali considerate sono state inserite in un modello concettuale DPSIR (Driving forces, Pressures, States, Impacts, Responces) dove sono stati prospettati, in via qualitativa, alcuni scenari in funzione di possibili risposte gestionali verosimilmente attuabili, al fine di modificare le pressioni che insistono sul sistema suolo-vegetazione delle pinete ravennati.

Salt stress responses in pear and quince: physiological and molecular aspects

The productivity of agricultural crops is seriously limited by salinity. This problem is rapidly increasing, particularly in irrigated lands. Like almost all the fruit tree species, Pyrus communis is generally considered a salt sensitive species, but only little information is available on its behavior under saline conditions. Previous studies, carried out in the Department of Fruit Tree and Woody Plant Science (University of Bologna), focused their attention on pear and quince salt stress responses to understand which rootstock would be the most suitable for pear in order to tolerate a salt stress condition. It has been reported that pear and quince have different ability in the uptake, translocation and accumulation of chloride (Cl-) and sodium (Na+) ions, when plants were irrigated for one season with saline water (5 dS/m). The aim of the present work was to deepen these aspects and investigate salt stress responses in pear and quince. Two different experiments have been performed: a “short-term” trial in a growth chamber and a “long-term” experiment in the open field. In the short-term experiment, three different genotypes usually adopted as pear rootstocks (MC, BA29 and Farold®40) and the pear variety Abbé Fétel own rooted have been compared under salt stress conditions. The trial was performed in a hydroponic culture system, applying a 90 mM NaCl stress to half of the plants, after five weeks of normal growth in Hoagland’s solution. During the three-weeks of salt stress treatment, physiological, mineral and molecular analyses were performed in order to monitor, for each genotype, the development of the salt stress responses in comparison with the corresponding “unstressed” plants. Farold®40 and Abbé Fétel own rooted showed the onset of leaf necrosis, due to salt toxicity, one week before quinces. Moreover, quinces displayed a significant delay in premature senescence of old leaves, while pears emerged for their ability to regenerate new leaves from apparently dead foliage with the salt stress still running. Physiological measurements, such as shoots length, chlorophyll (Chl) content, and photosynthesis, have been carried out and revealed that pears exhibited a significant reduction in water content and a wilting aspect, while for quinces a decrease in Chl content and a growth slowdown were observed. At the end of the trial, all plants were collected and organs separated for dry weight estimation and mineral analyses (Cu, Fe, Mn, Zn Mg, Ca, K, Na and Cl). Mineral contents have been affected by salinity; same macro/micro nutrients were altered in some organs or relocated within the plant. This plant response could have partially contributed to face the salt stress. Leaves and roots have been harvested for molecular analyses at four different times during stress conditions. Molecular analyses consisted of the gene expression study of three main ion transporters, well known in Arabidopsis thaliana as salt-tolerance determinants in the “SOS” pathway: NHX1 (tonoplast Na+/H+ antiporter), SOS1 (plasmalemma Na+/H+ antiporter) and HKT1 (K+ high-affinity and Na+ low-affinity transporter). These studies showed that two quince rootstocks adopted different responsive mechanisms to NaCl stress. BA29 increased its Na+ sequestration activity into leaf vacuoles, while MC enhanced temporarily the same ability, but in roots. Farold®40, instead, exhibited increases in SOS1 and HKT1 expression mainly at leaf level in the attempt to retrieve Na+ from xylem, while Abbé Fétel differently altered the expression of these genes in roots. Finally, each genotype showed a peculiar response to salt stress that was the sum of its ability in Na+ exclusion, osmotic tolerance and tissue tolerance. In the long-term experiment, potted trees of the pear variety Abbé Fétel grafted on different rootstocks (MC, BA29 and Farold®40), or own rooted and also rootstocks only were subjected to a salt stress through saline water irrigation with an electrical conductivity of 5 dS/m for two years. The purposes of this study were to evaluate salinity effects on physiological (shoot length, number of buds, photosynthesis, etc.) and yield parameters of cultivar Abbé Fétel in the different combinations and to determine the salt amount that pear is able to tolerate over the years. With this work, we confirmed the previous hypothesis that pear, despite being classified as a salt-sensitive fruit tree, can be cultivated for two years under saline water irrigation, without showing any salt toxicity symptoms or severe drawbacks on plant development and production. Among different combinations, Abbé Fétel grafted on MC resulted interesting for its peculiar behaviors under salt stress conditions. In the near future, further investigations on physiological and molecular aspects will be necessary to enrich and broaden the knowledge of salt stress responses in pear.

L'Oikeiosis degli Stoici: Una lettura evolutiva

La ‘dottrina stoica dell’oikeiosis’ viene comunemente rappresentata come una teoria unitaria – una dottrina, appunto – che farebbe derivare l’oikeiosis sociale (in latino, communis hominum inter homines commendatio) da quella riflessiva o personale. Tale derivazione solleva però numerosi interrogativi e sarà fatta oggetto di una valutazione critica nella seconda parte del presente lavoro (corrisponde ai capitoli secondo e terzo). Nel primo capitolo, in mancanza di una definizione concettuale di oikeiosis, cercheremo di stabilire il significato dell’espressione complessa oikeiosis pros heautó. Si noti che il termine ‘oikeiosis’ non è un neologismo stoico; gli Stoici, però, nell’adottarlo come termine tecnico, ne modificano la sintassi e quindi il significato. Per apprezzare la portata di tale cambiamento è necessario procedere a un esame preliminare delle occorrenze non filosofiche più significative, sia del nome ‘oikeiosis’ sia della forma verbale corrispondente.