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In vitro culture of stemless carline thistle was established using immature zygotic embryos. A satisfactory bud multiplication was achieved on MS medium supplemented with BAP (1 mg L−1) and IAA (0.2 mg L−1). Maximum rooting of buds was induced upon short cultivation (4 or 8 days) on an auxin-supplemented medium. Highest number of roots was obtained with NAA in the medium while the longest roots developed on the IAA-supplemented medium. Plantlets that subsequently developed were in rosette form if grown in light (16/8 h light to darkness photoperiod) and with elongated stems if raised in darkness. Light grown plantlets treated with GA3 showed dose dependent stem increase in length, reaching maximum at the concentration of 10−4 M. This was correlated with the length and the average number of internodes. If cultivated in the presence of ancymidol, dark grown plantlets showed reduced stem length. However, the inhibitory effect of the growth retardant on stem elongation was completely overcome by the addition of GA3.

The Empress tree (Paulownia tomentosa Steud.) is a fast growing deciduous tree originating from East Asia. It is grown as an ornamental plant, but can also be used as industrial wood. However, in some parts of North America, this species is considered invasive, with high impact on autochthonous populations. We have investigated whether post-fire expansion of this species can be explained at the germination level by analyzing the interaction between physical (light and temperature) and chemical (smoke and nitrogenous compounds) fire-related cues in the regulation of P. tomentosa germination. Light is the key environmental signal in the induction of germination of positively photoblastic P. tomentosa seeds. Smoke, applied in the form of extract (liquid smoke [LS]), stimulates light-induced germination if applied during imbibition, or shortly after the inductive irradiation. This stimulatory effect of LS can be effectively prevented by far-red light, suggesting that the mechanism of smoke action is phytochrome related. The LS had no effect on the germination percentage when applied during the phase of radicle protrusion. However, LS reduced radicle elongation and slowed its protrusion. The LS had no effect on the optimal temperature range of germination (23-27 degrees C). The combined action of LS and KNO(3) in light-induced germination was more effective then when each chemical was applied separately. It can be concluded that all tested components of fire, except elevated temperature, operate to stimulate germination of P. tomentosa seeds, suggesting that the post-fire invasive potential of this species can, at least in part, be explained at the germination level. Ministry of Science and Technological Development of the Republic of Serbia [143031]

The compositions of the essential oils of wild Daucus carota L. (Apiaceae) from the ripe fruits, unripe fruits, flowers, root, leaves, and stem, collected in Serbia, were analyzed by GC and GUMS. The oils from all samples contained alpha-pinene (7.05-51.23%) and sabinene (2.68-36.69%) as major constituents. The other dominant compound in ripe and unripe fruits essential oil was alpha-muurolene (8.23-10.97%). Antibacterial and antifungal properties of these oils, against eight bacterial and eight fungal strains, were tested by a microdilution technique. The most prominent biological activity was achieved by isolated essential oils of ripe and unripe fruits of D. carota. Ministry of Science of Serbia [143031, 143041]

Essential oils were isolated from the aerial pails during the flowering and vegetative phases, roots and seeds of the plant Portenschlagiella ramosissima and their antimicrobial activities against bacteria (Salmonella enteritidis, Escherichia coli, Micrococcus flavus, Bacillus subtilis, Staphylococcus aureus) and micromycetes (Aspergillus flavus, A. niger, A. versicolor, A. ochrachloron, Penicillium funiculosum, Trichoderma viride) were tested. Among tested bacterial and fungal species were plant pathogens, food poisoning species, animal and human pathogens. The main component in all oils samples was myristicin (61.1-91.5%). Antimicrobial activity of oils was tested using the micro-dilution and disc-diffusion methods. All of the oils tested showed activity. null

The chemical composition and antifungal activity of the essential oil of an endemic Serbian plant Nepeta rtanjensis Diklić & Milojević was studied. The essential oil was isolated from cultivated plants. Inhibition of mycelia growth of five micromycetes, two Alternaria species originally isolated from N. rtanjensis, Cladosporium cladosporoides, Trichoderma viride and Bipolaris spicifera, were tested using the agar dilution method. The essential oil of N. rtanjensis, the main component of which was 4aα,7α,7αβ-nepetalactone, showed strong antifungal activity against all the tested micromycetes. The minimum inhibitory concentration of N. rtanjensis essential oil ranged from 0.6 to 1.4 μg mL-1. The fungi most sensitive to the tested oil were Alternaria species, while Trichoderma viride was the most resistant. U ovom radu prezentovan je hemijski sastav i antifungalna aktivnost etarskog ulja endemične biljke Nepeta rtanjensis Diklić & Milojević. Etarsko ulje je izolovano iz kultivisanih biljaka. Inhibicija micelijalnog rasta pet mikromiceta, dve vrste roda Alternaria, izolovane sa N. rtanjensis, Cladosporium cladosporioides, Trichoderma viride i Bipolaris spicifera, testirana je makrodilucionom metodom. Etarsko ulje N. rtanjensis, čija je glavna komponenta 4aα,7α,7aβ-nepetalakton pokazuje jaku antifungalnu aktivnost u odnosu na sve testirane mikromicete. Minimalna inhibitorna koncentracija (MIC) etaskog ulja bila je u rasponu od 0,6 μg mL-1 do 1,4 μg mL-1. Najveću osetljivost na testirano ulje pokazale su vrste roda Alternaria dok je Trichoderma viride bila najotpornija. Projekat ministarstva br. 143041.

The antifungal activity of Nepeta rtanjensis Diklić et Milojević essential oil on mycelia growth has been performed by macrodilution method. The most efficient impact of N. rtanjensis essential oil on mycelia growth in vitro was found in Alternaria species with the same value of minimal inhibitory quantity (MIQ) of 0.6 μl/ml. Bipolaris spicifera and Cladosporium cladosporoioides had MIQ values of 1.0 μl/ml whereas Trichoderma viride with MIQ value of 1.6 μl/ml showed the most efficient defense against the essential oil examined. The values of minimal fungicidal quantity (MFQ) in Alternaria sp. 2, B. spicifera and C. cladosporioides match the MIQ values whereas MFQ values in Alternaria sp. 1 is 0.8 μl/ml, and in T. viride 1.8 μl/ml. Makrodilucionom metodom testiran je uticaj etarskog ulja endemične biljke Nepeta rtanjensis (Lamiaceae) na micelijalni rast mikromiceta: Alternaria sp. 1, Alternaria sp. 2, Bipolaris spicifera, Cladosporium cladosporioides i Trichoderma viride. Hemijska analiza etarskog ulja N. rtanjensis pokazala je apsolutnu dominaciju 4aα, 7α, 7aβ nepetalaktona (79.89%). Najefikasniji uticaj na rast micelije in vitro zabeležen je kod vrsta roda Alternaria sa istom vrednošću minimalne inhibitorne količine (MIK) od 0.6 μl/ml. Bipolaris spicifera i Cladosporium cladosporioides su imali MIK 1.0 μl/ml, dok je Trichoderma viride, sa vrednošću MIK od 1.6 μl/ml, pokazala najveću otpornost na dejstvo ispitivanog ulja. Vrednosti minimalne fungicidne količine (MFK) se kod Alternaria sp. 2 (0.6 μl/ml), B. spicifera (1.0 μl/ml) i C. cladosporioides (1.0 μl/ml) poklapaju sa vrednostima MIK, dok je kod Alternaria sp. 1 MFK 0.8 μl/ml, a kod T. viride 1.8 μl/ml. Etarsko ulje N. rtanjensis pokazalo je jako antifungalno dejstvo na rast micelije testiranih mikromiceta. null

In this paper we present voltage-current-power characteristics of a plasma needle operating in the flow of helium at atmospheric pressure. In addition, we show some examples of how such a plasma affects plant tissues. In the characterization of the plasma needle, current and voltage waveforms were recorded by two derivative probes. These two probes are similar to the probes previously used by Puac et al for measuring transmitted power in low pressure CCP rf discharge. The instantaneous power was calculated from current and voltage waveforms and U-I characteristics of the discharge were determined. Regimes of operation with and without the grounding ring at the tip of the needle were considered. We have chosen two model systems to study the effect of the plasma needle on plant cells and tissues: sweet fern gametophyte (prothallus) and calli produced in vitro. Since the prothallus consists of a single layer of cells, the cytological effects could be easily examined. In addition, calli and prothallus are easy to manipulate and in vitro culture provides a possibility to work under constant and controlled conditions. null

The germination of Empress tree (Paulownia tomentosa Steud.) seeds is phytochrome-controlled. Liquid smoke could not induce germination in darkness but red light irradiation of liquid smoke imbibed seeds induced a high percentage of germination. Maximum germination was achieved at liquid smoke concentration of 0.1% (v/v) when present during the imbibition phase or during the phase of phytochrome activity. The light requirement of these seeds could be completely substituted by exogenously applied gibberellins. In the presence of liquid smoke, optimal concentrations of GA(3), GA(4), and GA(9) necessary for inducing germination were several times lower than in the controls, while that of GA(7) was equally active when applied at a concentration one order of magnitude lower. The inhibitory effect of the applied growth retardants was strongly reduced and liquid smoke, in the presence of retardants, allowed light-induced germination, if applied simultaneously or after retardants treatment. null

This study was conducted to investigate the effect of physical and chemical features on metabolic production in plant cell culture. The best multiplication of Frangula alnus Mill. shoots (8.84 +/- 1.11) was obtained on woody plant medium ( WPM) medium with indole-3-acetic acid (IAA) (0.1 mg l(-1)) and 6-benzylaminapurine (BAP) (1.0 mg l(-1)), but the highest metabolite production (1731 mg/100 g of total anthraquinone (AQ) aglycones) was in the shoots grown on the MS medium with addition of 1-naphthilaceneacetic (NAA) (0.1 mg l(-1)) and thidiazuron (TDZ) (0.1 mg l(-1)). The best multiplication of Frangula rupestris (Scop.) Schur. shoots (6.20 +/- 0.53) was obtained on MS medium supplemented with BAP (0.5 mg l(-1)). The highest metabolite production (451 mg/100 g of total anthraquinone aglycones) was in the shoots grown on medium with 2,4-D (0.1 mg l(-1)) and BAP (0.5 mg l(-1)). For the multiplication of Rhamnus catharticus L. shoots, the best results (2.8 +/- 0.7) were obtained on the medium with combination of 2,4-D (0.1 mg l(-1)) and kinetine (Kin) (1.0 mg l(-1)). The best synthesis of anthraquinones (AQs) (1205 mg/100 g of total AQ aglycones) was in the shoots, which were grown on MS medium supplemented with 2,4-D (0.1 mg l(-1)). null

A wide range of sucrose, fructose, and glucose levels in culture media was tested in vitro in order to determine those that provide optimum growth, morphogenesis, and the production of secondary metabolites in Nepeta rtanjensis Diklic and Milojevic shoots. The effect of different concentrations of the carbohydrates in culture media on the internal carbohydrate status of N. rtanjensis shoots was also determined. Our results show that in vitro growth and development of N. rtanjensis, as well as nepetalactone accumulation, are significantly affected by both the type of carbohydrate and its concentration in the culture medium. Glucose proved to be the most efficient carbon and energy source. null

A micropropagation protocol was developed for the conservation of critically endangered Serbian perennial Nepeta rtanjensis (Lamiaceae). Rooted shoots were obtained from one-node stem segments and shoot tips on a half-strength Murashige and Skoog (MS) medium without growth regulators. The best pH of the medium for axillary buds induction and for rooting of shoots was found to be at 7 and/or 7.2 respectively. The addition of cytokinins to the culture medium did not significantly stimulated auxillary bud production as compared to the control. On the contrary, on media supplemented with high cytokinin concentrations, only dwarf shoots with rudimentary roots were obtained. All tested concentrations of 6-benzylaminopyrine (BAP) and kinetine (Kn) in combination with 0.1 mg 1(-1) indole-3-acetic acid (IAA) negatively affected the elongation and rooting of shoots. Plants micropropagated on hormone free medium and rooted in vitro were successfully acclimatized in greenhouse and in open field conditions. The result of successful acclimatization was the production of more than 7000 plantlets with normal sexually reproduction. They flowered, fruited and produced seeds which exhibited 47% germination. The survival rate of plants that were transferred to the open field for the acclimatization and exposed to the winter chill was 99%. The reintroduction of N. rtanjensis occurred in May 2004. One thousand plantlets were planted within the historic range of this plant species. The survival rate was also 99%. null

Yellow pheasant´s Eye is a herbaceous plant from dry ressy areas. Owing to habitat destruction and over- collection for ornamental and medical purposes A. vernalis L. has became scarce in central and south Europe. The reasons for A. vernalis threatened are manyfold. The low seeds germination rate is significant. According to our investigation the main cause of fruit destruction is fungal infection. From the surface of the fruits, collected in Deliblato Sands, the following micromycetes has been isolated and determinated: Fusarium solani (Mart) Sacc., Fusarium sporotrichioides Sherb., Alternaria sp. and Drechslera sp. Histologycal analysis showed the presence of conidiomata and conidia Phoma sp. in the seeds. Gorocvet je zeljasta biljka sušnih predela. U centralnoj i južnoj Evropi, kao tipično stepska biljka, ima ograničeno rasprostranjenje, dok je u istočnoj Evropi brojnost populacija u opadanju. U centralnoj i južnoj Evropi ova biljka postaje sve ugroženija zbog preterane eksploatacije od strane čoveka, u medicinske svrhe, kao i zbog narušavanja njenog staništa. A. vernalis je kao ugrožena biljka uključena u crvene knjige. Jedan od razloga ugroženosti A. vernalis je niska sposobnost klijavosti semena. Prema našim istraživanjima glavni uzrok destrukcije plodova je infekcija gljivama. Sa površine plodova A. vernalis, sakupljenih u Deliblatskoj peščari, izolovane su i determinisane sledeće mikromicete: Fusarium solani, Fusarium sporotrichioides, Alternaria sp., Drechslera sp. Histološki preseci inficiranih plodova pokazuju značajne promene: perikarp i semena su razoreni micelijom i plodonosnim telima gljive iz roda Phoma, prema mišljenju mikoloških eksperata (Kew Garden, Engleska) koji su potvrdili identifikaciju. Ovi rezultati donose nova pitanja, ideje i rešenja o konceptu ugroženosti biljnih vrsta. null

The chemical composition and antifungal activity of the corolla, calyx and leaf oils of Salvia brachyodon were analyzed by GC and GUMS. The oils were hydrodistilled from the leaves, corolla and calyx, separately. The leaf oil contained 1,8-cineole (33.0%), alpha-pinene (12.7%), camphene (12.5%) and beta-pinene (11.3%) as the most abundant constituents. The oil isolated from the calyx contained beta-pinene (27.6%), alpha-pinene (16.2%), camphene (13.7%), borneol (13.2%) and camphor (12.4%) as major components, while in the corolla oil the main components were beta-pinene (31.7%), borneol (12.8%), alpha-pinene (11.8%), camphene (6.7%) and alpha-pinene (11.8%). The last sample, however, was the most complex, because of the presence of higher concentration of sesquiterpenes and presence of diterpenes, which were not recorded in the other samples investigated. Antifungal activities of the essential oils were determined by the microdilution method against Aspergillus niger, Trichophyton mentagrophytes and Candida albicans. The oil from the calyx possessed the best antifungal activity against all the fungal species tested. null

The effect of some respiratory inhibitors on light-induced Paulownia tomentosa Steud. seed germination was studied. Millimolar solution of sodium azide was sufficient to completely prevent germination induced by a 5-min red light pulse. The inhibitory effect of azide was absent if seeds were rinsed before phytochrome activation by light. Sodium azide was effective only if present in the period of Pfr activity. The escape time from azide inhibition compared to the escape from far-red light action, was delayed for about 24 hours. When azide was applied after phytochrome activation, its effect depended on how long it was present in the incubation medium. The removal of azide allowed full restoration of germination by another red light pulse and the far-red escape time did not differ from the escape of untreated, i.e. water-imbibed seeds. Potassium cyanide alone did not produce any effect in light-stimulated germination of these seeds. However, it counteracted the inhibitory effect of azide in light-stimulated germination, if applied simultaneously at a concentration three times higher. Ispitivan je efekat nekih inhibitora disanja na klijanje svetlošću indukovanih semena Paulownia tomentosa. Potpuna inhibicija klijanja, koje je indukovano sa 5 minuta crvene svetlosti, mogla je da se postigne već milimolarnim rastvorom natrijum azida. Inhibitorni efekat azida je izostajao ako se semena isperu pre aktiviranja fitohroma osvetljavanjem. Natrijum azid je bio efektivan samo ako je prisutan u semenima u periodu aktivnosti Pfr. Vreme za koje semena izbegavaju inhibitorni efekat azida je odloženo za oko 24 časa u poređenju sa istim za inhibitorno delovanje tamno crvene svetlosti. Kada se azid odstrani, dodatni puls crvene svetlosti dovodi do potpunog obnavljanja sposobnosti za maksimalno klijanje, a vreme za koje semena izbegavaju inhibitorni efekat crvene svetlosti se ne razlikuje od istog kod netretiranih semena, tj. onih koji su inbibirala u vodi. Kalijum cijanid nema nikakav uticaj na klijanje semena indukovanih svetlošću. Međutim, ako se kalijum cijanid primeni simultano sa natrijum azidom, u tri puta većoj koncentraciji, on sprečava inhibitorni efekat natrijum azida na klijanje indukovano svetlošću. Projekat ministarstva br. 1696

Centaury seeds are light-requiring. Long-term red light irradiation caused more than 80% of seeds to germinate. Seeds did not germinate in darkness. Gibberellic acid and GA7 can replace light, but N-substituted phtalimide AC 94,377 was ineffective. Light-induced germination was inhibited by abscisic acid and growth retardants such as ancymidol, tetcyclacis, and paclobutrazole. Growth retardant-caused inhibition can be overcome by the addition of gibberellic acid. Klijanje semena kičice je zavisno od svetlosti. Dugotrajno osvetljavanje crvenom svetlošću dovodi do klijanja preko 80% semena. Semena ne klijaju u mraku. Giberelna kiselina i GA7 zamenjuju potrebu za svetlošću dok je N substituisani ftalimid AC 94,377 neefikasan. Klijanje indukovano svetlošću inhibiraju abscisinska kiselina i retardanti rastenja kao što su tetciklacis ancimidol i paklo-butrazol. Inhibicija klijanja izazvana retandantima može da se prevaziđe dodavanjem giberelina. Projekat ministarstva br. 1696

Essential oil of Juniperus excelsia Bieb M (Cupressaceae) was' evaluated for antifungal activities against 17 micromycetes (Alternaria alternata, Aspergillus niger, A. ochraceus, A. versicolor A. flavus, A. terreus, Cladosporium cladosporioides, Fusarium tricinctum, Penicillium ochrocloron, P funiculosum, Phomopsis helianthi, Trichoderma viride, Trichophyton mentagrophytes, T rubrum, T tonsurans, Epidermophyton floccosum, Microsporum canis). Among tested fungal species were the food poisoning species, plant, animal, and human pathogen. The essential oil showed antifungal activity. null

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Nitrogenous compounds, such as potassium nitrate, potentiate germination of different species of light-requiring seeds. Using light-induced Arabidopsis thaliana seed germination as a model system, our data suggested that only phytochrome A (phyA)-specific induced germination was affected after the exogenous application of nitrates, different nitric oxide (NO)-donors (such as organic nitrates) or sodium nitroprusside. The stimulative effect was very pronounced. Treated seed samples reached maximal germination after very short periods of red-light irradiation. To a far lesser extent, these substances affected phytochrome B (phyB)-specific induced germination. In phyB-specific induced germination, potassium nitrate was most effective, but germination percentages never exceeded 50%. The least effective was sodium nitroprusside, which practically did not affect phyB-specific induced germination. These results were confirmed using corresponding phytochrome mutants. null

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Using different nitric oxide releasing compounds and appropriate controls we have obtained data strongly suggesting the involvement of nitric oxide in the phytochrome controlled germination of Paulownia tomentosa seeds. Direct detection of nitric oxide, under various experimental conditions, was performed by a spin-trapping technique combined with electron paramagnetic resonance (EPR) spectroscopy. The addition of methylene blue prevented light-induced and NO donors-potentiated germination of P. tomentosa seeds. This inhibition could be completely overcome by addition of gibberellin. The promotive effect of nitrite was pH dependent, maximally pronounced at the pH range where nitrite undergoes dismutation and liberates nitric oxide. Under these conditions, nitrite exerted its efficacy at the same concentrations at which nitric oxide releasing compounds such as sodium nitroprusside (SNP), S-nitroso acetylpenicillamine (SNAP), and 3-morpholinosydnonimine (SIN-1), were the most effective. Likewise, the potentiation of P. tomentosa seed germination could be achieved by chemical reduction of nitrite with Na2S2O4 during which liberation of nitric oxide could be detected. null