First report on Meloidogyne chitwoodi hatching inhibition activity of essential oils and essential oils fractions

The Columbia root-knot nematode (CRKN), Meloidogyne chitwoodi, is an EPPO A2 type quarantine pest since 1998. This nematode causes severe damage in economically important crops such as potato and tomato, making agricultural products unacceptable for the fresh market and food processing. Commonly used nematicidal synthetic chemicals are often environmentally unsafe. Essential oils (EOs) may constitute safer alternatives against RKN. EOs, isolated from 56 plant samples, were tested against CRKN hatching, in direct contact bioassays. Some of the most successful EOs were fractionated and the hydrocarbon molecules (HM) and oxygen-containing molecules (OCM) fractions tested separately. 24 EOs displayed very strong hatching inhibitions (≥90 %) at 2 µL mL^?1 and were further tested at lower concentrations. Dysphaniaambrosioides, Filipendula ulmaria, Ruta graveolens, Satureja montana and Thymbra capitata EOs revealed the lowest EC₅₀ values (<0.15 µL mL^?1). The main compounds of these EOs, namely 2-undecanone, ascaridol, carvacrol, isoascaridol, methyl salicylate, p-cymene and/or γ-terpinene, were putatively considered responsible for CRKN hatching inhibition. S. montana and T. capitata OCM fractions showed hatching inhibitions higher than HM fractions. The comparison of EO and corresponding fractions EC₅₀ values suggests interactions between OCM and HM fractions against CRKN hatching. These species EOs showed to be potential environmentally friendly CRKN hatching inhibitors; nonetheless, bioactivity should be considered globally, since its HM and OCM fractions may contribute, diversely, to the full anti-hatching activity.     

A new dihydroxysterol from the marine phytoplankton Diacronema sp

Diacronema sp. was cultured and its sterols were separated by column chromatography on silica gel. The new sterol 24-ethyl-4alpha-methyl-cholestane-3,20-diol (1) was characterised by NMR and MS spectrometry, as well as (22E)-24-ethyl-4alpha-methyl-5alpha-cholest-22-en-3beta-ol (2) and beta-sitosterol, the major components of the sterol fractions. Neither the biosynthetic origin of the new dihydroxysterol nor its role in the biochemistry of Diacronema is known.     

A new acylated quercetin glycoside from Ranunculus lanuginosus

A new acylated quercetin glycoside, quercetin 3-O-(2-t-p-coumaroyl)-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside-7-O-beta-D-glucopyranoside (1), together with the known 3-(3,4-dihydroxyphenyl)lactic acid (2) were isolated from Ranunculus lanuginosus leaves and identified on the basis of detailed spectral analysis, including 2D-NMR spectrometry and ESI-MS.     

Stickstoffdüngungsversuche in einer Fichtenwuchsstockung (Picea abies Karst.) auf devastierter Kalkmergel-Rendzina: III. Einflüsse von Ern?hrungszustand und Inokulation auf die Inhaltsstoffe von Bast und Holz

In einem kombinierten Düngungs- und Infektionsversuch wurden die Beziehungen zwischen dem Ern?hrungszustand, dem Wachstum und der Rotf?uledisposition von N-Mangel-Fichten auf Kalkmergel-Rendzina geprüft. Die vorliegende Arbeit berichtet über die Wirkung der N-Düngung und künstlicher Infektionen mit Heterobasidion-Mycel auf den Gehalt an Extraktstoffen im Bast und Holz. Wurzelbast vom August (nicht aber vom April) von mehrmals gedüngten Fichten enthielt mehr Chloroform-und Ethanol/Wasser-Extrakt sowie Zucker- und Phenolkomponenten als die ungedüngten Varianten. Auch das Wurzelholz gedüngter Fichten war im August reicher an Extraktstoffen. Die N-Gaben steigerten au?erdem in beiden Geweben den Gehalt an l?slichen N-Verbindungen. Im Stamm erh?hte die Düngung die Gehalte an. Methanol-Extrakt sowie an einigen N-haltigen und phenolischen Verbindungen nur im ?u?eren Splint.     

Variations in soil chemical properties and microbial biomass in artificial gaps in silver fir stands

Changes in soil chemical and microbiological parameters in small (185 m²) and medium (410 m²) gaps, created in mature silver fir (Abies alba Mill) stands (mean height 30 m) in the Calabrian Apennines (Southern Italy), were studied over 2 years. Medium gaps had high soil temperature and photosynthetically active radiation (PAR) transmittance and low soil moisture. Within small gaps we detected a greater amount of organic matter, with respect to under canopy cover sites and medium gaps. Moreover, a different trend of the organic matter between small and medium gaps was observed. In the medium gaps, with respect to under canopy cover sites and small gaps, we found a relatively low content of organic matter, associated to a lower amount of humic acid, which suggested that the organic substrate undergoes a mineralization rather than a humification process. An opposite trend was observed in small gaps, where the increase of organic matter content, associated to an increase of humic acid and microbial biomass, suggested a better humification process. Moreover, in small gaps the highest level of urease and the greatest fluorescein diacetate (FDA) hydrolysis were observed. The different trend of organic matter observed in small and medium gaps may be related to changes in the environmental conditions. PAR transmittance, significantly higher in medium gaps, contributed to increase soil temperature and decrease soil moisture, affecting soil microbial populations and organic matter trend. These results suggest that the creation of small gaps represents the silvicultural practice with minor environmental impact.     

Stickstoffdüngungsversuche in einer Fichtenwuchsstockung (Picea abies Karst.) auf devastierter Kalkmergel-Rendzina: III. Einflüsse von Ernährungszustand und Inokulation auf die Inhaltsstoffe von Bast und Holz

Zusammenfassung In einem kombinierten Düngungs- und Infektionsversuch wurden die Beziehungen zwischen dem Ern?hrungszustand, dem Wachstum und der Rotf?uledisposition von N-Mangel-Fichten auf Kalkmergel-Rendzina geprüft. Die vorliegende Arbeit berichtet über die Wirkung der N-Düngung und künstlicher Infektionen mit Heterobasidion-Mycel auf den Gehalt an Extraktstoffen im Bast und Holz. Wurzelbast vom August (nicht aber vom April) von mehrmals gedüngten Fichten enthielt mehr Chloroform-und Ethanol/Wasser-Extrakt sowie Zucker- und Phenolkomponenten als die ungedüngten Varianten. Auch das Wurzelholz gedüngter Fichten war im August reicher an Extraktstoffen. Die N-Gaben steigerten au?erdem in beiden Geweben den Gehalt an l?slichen N-Verbindungen. Im Stamm erh?hte die Düngung die Gehalte an. Methanol-Extrakt sowie an einigen N-haltigen und phenolischen Verbindungen nur im ?u?eren Splint. Die Inokulation der St?mmchen durch Anbohren induzierte die Bildung von Reifholz und übergangszonen (zwischen Splint und verf?rbtem Reifholz), die besonders reich an Petrolether-Extrakt, Methanol-Extrakt und Lignanen waren. Diese Reaktionen der Fichten waren durch Düngung nicht beeinflu?t, da sie in inneren, vor der Düngung angelegten Stammbereichen abliefen. Die wiederholte N-Düngung führte im Wurzelbast vom April zu geringerer, in den August-Proben zu gesteigerter Hemmwirkung gegenüber Heterobasidion annosum im Biotest. Die Hemmung im August war mit dem Gehalt an phenolischen Komponenten positiv korreliert. Wurzelholz und ?u?erer Stamm-Splint von gedüngten B?umchen enthielten mehr Stickstoff und mehr Aminos?uren als die Kontrollfichten und stellten deshalb ein besonders günstiges, Substrat für den Pilz dar. Die Hemmwirkung des Reifholzes war positiv korreliert mit dem Gehalt an Methanol-Extrakt bzw. an Lignanen; ein Düngungseinflu? war nicht erkennbar. Für Stammholzfraktionen der inokulierten Fichten fand sich ein positiver Zusammenhang zwischen der Hemmwirkung und dem Gehalt an harzartigen Komponenten, die als Reaktion des Baumes auf die Verletzung vermehrt produziert wurden.

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Nitrogen fertilization experiments in a Norway spruce stand (Picea abies Karst.) of stagnant growth on devastated marly rendzina: III. Influence of fertilization and inoculation on the extractives in phloem and wood

Summary A combined fertilization and inoculation experiment was designed to study the interrelationships between nutritional status, growth, and susceptibility to heart rot of planted N-deficient Norway spruce growing on a rendzina soil (Rendoll). The present report describes the impact of N-fertilization and of inoculation withHeterobasidion annosum mycelium on the contents of extractives in the phloem and in the wood. Root phloem in August (but not in April) of spruces fertilized repeatedly contained more chloroform- and ethanol/water-soluble substances, and more sugars and phenolic compounds as compared with phloem from the controls. Root wood of fertilized trees was also richer in extractives. N-fertilization, in addition, always raised the contents of soluble N-fractions in both tissues, as well as the amount of methanol-soluble substances, N-containing compounds, and phenolics in the outer sapwood region of the stem. Inoculation of stems by introducingH.a. mycelium into auger holes induced the formation of heartwood and of transition zones (between sapwood and heartwood) which were especially rich in petrolether- and methanol-soluble substances and in lignans. These reactions were not influenced by fertilization, since they were located in the inner stem regions formed in advance of fertilization. Repeated N-application reduced the fungistatic effect onH.a. of root phloem in April but increased it in August. The inhibition in August was positively correlated with the contents of phenolic compounds. Root wood and outerstem sapwood of fertilized spruces were richer in N and amino acids than control trees and therefore offered a favorable substratum for the fungus. The inhibitory effect of heartwood was positively related to the content of methanol-soluble compounds and lignans; an effect of fertilization could not be found. For wood fractions of inoculated trees a positive interrelationship was detected between fungistatic effect and content of resin compounds, the production of which was promoted as a reaction of the tree to wounding.

     

Traditional phytotherapy in Central Italy (Marche, Abruzzo, and Latium)

In this study, the more significant results of extensive ethnopharmacobotanical research carried out by the author in the years 1977-2000 in 175 localities of three regions of Central Italy (Marche, Abruzzo, and Latium) have been reported and compared. The usages of 80 species belonging to 36 families are described, of which 71 were used in human therapy and 29 in veterinary medicine. Uses are suited with the number of localities in which they have been mentioned. Among the wild plant mainly still used, Malva sylvestris, Urtica dioica, and Sambucus nigra are particularly highly considered, while major uses of plants concern these plants in addition to Allium sativum, Rubus ulmifolius, Parietaria diffusa, Cynodon dactylon, and Ficus carica. Unusual phytotherapic uses concern Brassica oleracea, Taraxacum officinale (warts), Ruscus aculeatus, S. nigra (chilblains), Allium cepa (chilblains; to remove thorns and splinters), Juglans regia, R. ulmifolius (burns), and Euphorbia paralias (bites of weevers). Among new uses with only one quotation, we remember Cirsium arvense (intestinal disturbances), Centaurea bracteata (cough), Lupinus albus (calluses), Melittis melissophyllum (eye inflammations, antispasmodic), and Artemisia absinthium (tendon inflammations), while among plants employed in various regions with interesting less-known properties, there are C. arvense (emergency haemostatic), P. diffusa (insect bites), and Scrophularia canina (antiseptic and cicatrizing agent for wounds in bovines and sheep).     

Growth and nutrient accumulation of Brazil nut trees (Bertholletia excelsa) in agroforestry at different fertilizer levels

The Brazil nut tree(Bertholletia excelsa) is a frequent component of agroforestry systems in the Amazon because of its adaptation to nutrient-poor upland soils and multiple uses.We investigated the aboveground biomass production(kg dry weight),nutrient uptake and requirements(N,P,Ca,Mg,K) of Brazil nut trees of different sizes grown under agroforestry conditions and fertilized at different levels.Eight of 70 experimental trees with different size were harvested and stem,branches and leaves were separated.Nutrient contents were determined for three trees of varying size.Average tree growth was fast,but variability was high,suggesting considerable potential for the improvement of this economically important species.The trees responded to increased levels of fertilizer and lime with significantly increased foliar nutrient contents and growth,probably because of the improved availability of Mg and Ca for which the species seems to have a relatively high demand.In contrast to Brazil nut trees grown in forest or dense plantations,the agroforestry trees invested a substantial part of their biomass and nutrients in large branches and developed spreading crowns.To improve stem form,reduce competition with associated crops for light and recycle nutrients,regular pruning of lower branches or planting arrangements that favor self-pruning are recommended.These measures would also increase the recycling of Ca and Mg,large quantities of which are contained in the branches.