2-naphthoxyacetic Acid Research Articles

Syntheses, structural characterization, and DPPH radical scavenging activity of cocrystals of caffeine with 1- and 2-naphthoxyacetic acids

Caffeine:1-naphthoxyacetic acid [(caf)(1-naa)] and caffeine:2-naphthoxyacetic acid [(caf)(2-naa)] cocrystals have been synthesized and single crystals were grown by slow evaporation technique. The structures of the grown crystals were elucidated using single crystal X-ray diffraction analysis. Both the cocrystals belong to the monoclinic crystallographic system with space group P21/c, Z=4, and α=γ=90°, whereas β=111.4244(18)° for [(caf)(1-naa)] and β=109.281(6)° for [(caf)(2-naa)]. The crystal packing is predominantly stabilized by hydrogen bonding and π–π stacking interactions. The presence of unionized –COOH functional group in both the cocrystals was identified by FTIR spectral analysis. Thermal behavior and stability of both the cocrystals were studied by TGA/DTA analyses. Solvent-free formation of these cocrystals was confirmed by powder X-ray diffraction analyses. The theoretical energy of cocrystals showed that the formers have higher energy than cocrystals 1 and 2. DPPH radical scavenging activity of cocrystals 1 and 2 is slightly greater than the formers.

Simultaneous determination of plant growth regulators in environmental samples using chemometrics-assisted excitation–emission matrix fluorescence: Experimental study on the prediction quality of second-order calibration method

In this work, with the purpose of developing an effective and inexpensive method, excitation–emission matrix fluorescence data and second-order calibration method based on the self-weighted alternating trilinear decomposition (SWATLD) algorithm were combined for simultaneous determination of 2-naphthoxyacetic acid (NOA) and 1-naphthaleneacetic acid methyl ester (NAAME) in environmental samples, i.e. soil and sewage samples. In order to investigate the prediction quality of the proposed method, different strategies, such as taking spectroscopic measurements in the presence of different matrix interferents and at different fluorescence spectrophotometers, were introduced to build calibration models and comparisons among them were done subsequently. The root-mean-square error of prediction and t-test were used to compare different SWATLD-based calibration models. The limits of detection obtained for NOA and NAAME were 0.36–0.95ngmL−1 and 1.32–2.69ngmL−1, respectively, for different models. Such a chemometrics-based protocol may possess great potential to be extended as a promising alternative for more practical applications in environment monitoring and for the design of small intelligent and field-portable analytical instruments that rely on statistical discrimination, not complete instrumental separation, of the target analytes even in the presence of unknown and uncalibrated interferences.

An improved method for micropropagation and regeneration of date palm (Phoenix dactylifera L.)

We developed a novel large-scale micropropagation pathway for date palm (Phoenix dactylifera L.) based on organogenesis. We obtained organogenic stems from shoot tip explants of the Moroccan date palm cultivar Najda, and investigated shoot proliferation from these organogenic stems in vitro on various media; Beauchesne medium (BM) and Murashige and Skoog medium (MS) at full-strength, half-strength, and one-third-strength, containing various concentrations (0, 0.25, 0.5, and 1 mg/L) of 2-naphthoxyacetic acid (NOAA) and kinetin. The optimal medium during the multiplication phase was half-strength Murashige and Skoog medium (MS/2) supplemented with 0.5 mg/L NOAA and 0.5 mg/L kinetin (23.5 morphologically superior shoots per explant, with low vitrification rates). For the shoot elongation phase, shoots were transferred to the same proliferation medium, or to MS or MS/2 media without plant growth regulators (PGRs). Shoots elongated rapidly and showed a high rate of root formation on media supplemented with PGRs. For example, on MS/2 medium containing 1 mg/L NOAA and 1 mg/L kinetin, the average shoot length was 15.1 cm, the average number of roots per shoot was 6.2, and their average length was 3.4 cm. On PGR-free media, shoots were shorter with wider and greener leaves, and had fewer roots. The plantlets were transferred to a greenhouse for acclimation. The survival rate after 2 months was related to the medium used during the elongation phase; >90 % of shoots that were cultured on PGR-free media survived, while there was a poor survival rate of shoots that had been cultured on media containing PGRs.

The effect of the method of application of growth regulators on fruit quality of 'Einset seedless' grape (Vitis sp. L.)

This study was conducted during the period 2006-2008 in the Faliszowice Vineyard in the Sandomierz Upland. The experiment evaluated yield quality of 'Einset Seedless' grape after the application of gibberellic acid (GA<sub>3</sub>) in the form of the growth regulator Arbostim 100 SL and 2-naphthoxyacetic acid (NOA) in the form of the growth regulator Betokson Super 050 SL. These growth regulators were applied during flowering by spraying the inflorescences or immersing them in whole at the following concentrations: 100 mg×L<sup>-1</sup> GA<sub>3</sub> - the treatment was performed once at full flowering (70-80% of open flowers); 50 mg×L<sup>-1</sup> GA<sub>3</sub> - the treatment was performed twice: at the beginning of flowering (20% of open flowers), and the second time at the end of flowering (80% of faded flowers); 50 mg×L<sup>-1</sup> GA<sub>3</sub> + 0.2% NOA - the treatment was performed once at full flowering; and 0.2% NOA - the treatment was performed once at full flowering. The study showed that the applied treatments had a beneficial effect on cluster and berry weight as well as on the number of berries per cluster in the grape variety 'Einset Seedless'. Gibberellic acid and the mixture of 50 mg×L<sup>-1</sup> GA<sub>3</sub> and 0.2% NOA were shown to have a significant effect on cluster and berry length; an exception were clusters and berries sprayed with 50 mg×L<sup>-1</sup> GA<sub>3</sub> whose length did not differ significantly compared to the control ones. The applied treatments slightly affected berry width in the grape variety under study. The growth regulators applied were found to have an adverse effect on extract content in 'Einset Seedless' fruit.

Simultaneous Determination of Plant Growth Regulators 1‐Naphthylacetic Acid and 2‐Naphthoxyacetic Acid in Fruit and Vegetable Samples by Room Temperature Phosphorescence

1-Naphthylacetic and 2-naphthoxyacetic acids belong to the synthetic branch of auxins. Auxins have attracted considerable interest as a subject of study by virtue of their biological and physiological significance. Their broad use as plant growth regulators has raised the need for simple, rapid, sensitive and selective analytical methods for their determination in real samples. The primary aim of this work was to develop an analytical method for the simultaneous determination of 1-naphthylacetic acid and 2-naphthoxyacetic acid in commercial technical formulations, tomato and various fruit types (apple, strawberry, orange and plum) by room temperature phosphorescence. Filtrated solutions of aqueous slurries from ecological fruit and tomato samples are acidified and then extracted with dichloromethane. Once the solvent is evaporated, the dried residue is dissolved in sodium dodecyl sulphate (a micellar agent), and supplied with thallium (I) nitrate as an external heavy atom source and sodium sulphite as deoxygenation agent to enhance the ensuing phosphorescence. The broad-band overlapping spectra for the two analytes were resolved by first- and second-derivative phosphorescence spectrometry. Zero-crossing measurements at 488.5 nm in the first-derivative spectrum and 469.5 nm in the second derivative spectrum exhibited a linear dependence on the 2-naphthoxyacetic acid and 1-naphthylacetic acid concentration, respectively. The detection limits as determined in accordance with the error propagation theory were 11.5 ng/mL for 1-naphthylacetic acid and 15.6 ng/mL for 2-naphthoxyacetic acid. The proposed method affords the determination of 1-naphthylacetic acid and 2-naphthoxyacetic acid in real samples with near-quantitative recoveries from agricultural products.

Micropropagation of commercially cultivated Henna (Lawsonia inermis) using nodal explants

Lawsonia inermis Linn. (Mehandi) is cultivated as cash crop in India particularly in Sojat area of Pali district, Rajasthan. Present investigation describes an efficient regeneration system for elite genotype of L. inermis using nodal segments. Optimum response in terms of percent cultures responding, days to bud break and average shoot length was observed on MS medium supplemented with 6-benzylaminopurine (BA; 2.0mgl(-1)). Shoot multiplication was influenced by plant growth regulators, repeated transfer of explants and addition of ammonium sulphate. Maximum shoots were regenerated on MS medium supplemented with BA (0.25mgl(-1)), kinetin (Kn; 0.25mgl(-1)), indole-3-acetic acid (IAA; 0.1mgl(-1)) and ammonium sulphate (150mgl(-1)). To reduce resources, time and labours costs, we have also attempted ex vitro rooting of shoots. About 95% shoots were rooted ex vitro on soilrite after treatment with indole-3-butyric acid (IBA; 300mgl(-1)) and 2-naphthoxy acetic acid (NOA; 100mgl(-1)) and establishment in soil successfully.

Micropropagation of Salvadora persica-a tree of arid horticulture and forestry

A micropropagation method for Jaal (Salvadora persica)—a tree of arid horticulture and forestry has been developed. Nodal segments of fresh shoot sprouts originated from axillary buds obtained from a plant around 35–40 years old lopped plant were used as explants for establishment of in vitro cultures. Surface-sterilized explants produced optimum number of shoots through activation of axillary buds on Murashige and Skoog’s (MS) medium containing 8.88 μM BA (6-benzyladenine) + additives (25 mgl−1 each of adenine sulphate, arginine, citric acid, 50 mgl−1 ascorbic acid). The shoot multiplication was influenced by the successive transfer of the mother explants for 4–5 passages. The maximum number (23.1 ± 0.73 shoots per explant) of shoots were regenerated on MS supplemented with 1.11 μM BA + 1.16 μM Kn (Kinetin) + 0.54 μM NAA (α-naphthalene acetic acid). About 90% shoots pulse-treated with a combination of 2460.27 μM Indole-3-butyric acid (IBA) + 494.56 μM NOA (2-naphthoxy acetic acid) were rooted ex vitro on soilrite within 15–18 days. Over 80% cloned plantlets were hardened successfully in a green house and transferred to polybag/pots.

Simultaneous determination of 13 phytohormones in oilseed rape tissues by liquid chromatography‐electrospray tandem mass spectrometry and the evaluation of the matrix effect

In the experiment, a high-performance liquid chromatography and electrospray ionization-tandem mass spectrometry with selected reaction monitoring was used to simultaneously determine various classes of phytohormones, including indole-3-acetic acid, α-naphthaleneacetic acid, 2-chlorobenzoic acid, 4-chlorobenzoic acid, indole-3-butyric acid, gibberellic acid, 2,4-dichlorophenoxyacetic acid, 2-naphthoxyacetic acid, abscisic acid, 2,3,5-triiodobenzoic acid, uniconazole, paclobutrazol and 2,4-epibassinolide in rape tissues. The analyses were separated by an HPLC equipped with a reversed-phase column using a binary solvent system composed of methanol and water, both containing 0.1% of formic acid. The matrix effect was also considered and determined. The technology was applied to analyze rape tissues, including roots, stems, leaves, flowers, immature pods and rape seeds. The rape tissues were subjected to ultrasound-assisted extraction and purified by dispersive solid-phase extraction, and then transferred into the liquid chromatography system. The detection limit for each plant hormone was defined by the ratio of signal/background noise (S/N) of 3. The results showed perfect linearity (R(2) values of 0.9987-1.0000) and reproducibility of elution times (relative standard deviations, RSDs,<1%) and peak areas (RSDs,<7%) for all target compounds.

Non-invasive quantification of endogenous root auxin transport using an integrated flux microsensor technique

Indole-3-acetic acid (IAA) is a primary phytohormone that regulates multiple aspects of plant development. Because polar transport of IAA is an essential determinant of organogenesis and dynamic tropic growth, methods to monitor IAA movement in vivo are in demand. A self-referencing electrochemical microsensor was optimized to non-invasively measure endogenous IAA flux near the surface of Zea mays roots without the addition of exogenous IAA. Enhanced sensor surface modification, decoupling of acquired signals, and integrated flux analyses were combined to provide direct, real time quantification of endogenous IAA movement in B73 maize inbred and brachytic2 (br2) auxin transport mutant roots. BR2 is localized in epidermal and hypodermal tissues at the root apex. br2 roots exhibit reduced shootward IAA transport at the root apex in radiotracer experiments and reduced gravitropic growth. IAA flux data indicates that maximal transport occurs in the distal elongation zone of maize roots, and net transport in/out of br2 roots was decreased compared to B73. Integration of short term real time flux data in this zone revealed oscillatory patterns, with B73 exhibiting shorter oscillatory periods and greater amplitude than br2. IAA efflux and influx were inhibited using 1-N-naphthylphthalamic acid (NPA), and 2-naphthoxyacetic acid (NOA), respectively. A simple harmonic oscillation model of these data produced a correlation between modeled and measured values of 0.70 for B73 and 0.69 for br2. These results indicate that this technique is useful for real-time IAA transport monitoring in surface tissues and that this approach can be performed simultaneously with current live imaging techniques.

Auxin influx inhibitors 1-NOA, 2-NOA, and CHPAA interfere with membrane dynamics in tobacco cells

The phytohormone auxin is transported through the plant body either via vascular pathways or from cell to cell by specialized polar transport machinery. This machinery consists of a balanced system of passive diffusion combined with the activities of auxin influx and efflux carriers. Synthetic auxins that differ in the mechanisms of their transport across the plasma membrane together with polar auxin transport inhibitors have been used in many studies on particular auxin carriers and their role in plant development. However, the exact mechanism of action of auxin efflux and influx inhibitors has not been fully elucidated. In this report, the mechanism of action of the auxin influx inhibitors (1-naphthoxyacetic acid (1-NOA), 2-naphthoxyacetic acid (2-NOA), and 3-chloro-4-hydroxyphenylacetic acid (CHPAA)) is examined by direct measurements of auxin accumulation, cellular phenotypic analysis, as well as by localization studies of Arabidopsis thaliana L. auxin carriers heterologously expressed in Nicotiana tabacum L., cv. Bright Yellow cell suspensions. The mode of action of 1-NOA, 2-NOA, and CHPAA has been shown to be linked with the dynamics of the plasma membrane. The most potent inhibitor, 1-NOA, blocked the activities of both auxin influx and efflux carriers, whereas 2-NOA and CHPAA at the same concentration preferentially inhibited auxin influx. The results suggest that these, previously unknown, activities of putative auxin influx inhibitors regulate overall auxin transport across the plasma membrane depending on the dynamics of particular membrane vesicles.

Determination of naphthalene by competitive fluorescence immunoassay

A reliable and sensitive competitive fluorescence immunoassay for the quantitative determination of naphthalene (NA) was developed. 2-naphthoxy acetic acid (NAA) was selected as the hapten of naphthalene. Active ester method (AEM) was used to couple the NAA to carrier proteins (bovine serum albumin) to form artificial immune antigen. Male New Zealand white rabbits were immunized with this antigen to obtain polyclonal antibodies, with which, a novel fluorescence immunoassay for detection of NA was described. Under best conditions, NA can be determined in the concentration range of 0.1-100 microg/L with a detection limit of 0.05 microg/L. The cross-reactivities of the anti-NA antibody to seven structurally related compounds were below 15%. Some environmental samples were analyzed with satisfactory results. It shows a good accuracy and suitability to analyze NA in environmental water.

Soluble and thermally stable polyamides bearing 1,1′-thiobis(2-naphthoxy) groups

A new-type of sulfide containing diacid (1,1′-thiobis(2-naphthoxy acetic acid)) was synthesized from 2-naphthol in three steps. Reaction of 2-naphthol with sulfur dichloride afforded 1,1′-thiobis(2-naphthol) ( TBN). 1,1′-Thiobis(2-naphthoxy acetic ester) ( TBNAE) was successfully synthesized by refluxing the TBN with methylcholoroacetate in the presence of potassium carbonate. The related diacid was synthesized by basic solution reduction of TBNAE. The obtained diacid was fully characterized and used to prepare novel thermally stable poly(sulfide ether amide)s via polyphosphorylation reaction with different aromatic diamines. The properties of these new polyamides were investigated and compared with similar polyamides. These polyamides showed inherent viscosities in the range of 0.39–0.87 dL g −1 in N, N-dimethylacetamide (DMAc) at 30 °C and at a concentration of 0.5 g dL −1. All the polyamides were readily soluble in a variety of polar solvents such as DMAc and tetrahydrofuran (THF). These polyamides showed glass transition temperature ( T g) between 241–268 °C. Thermogravimetric analysis measurement revealed the decomposition temperature at 10% weight loss ( T 10) ranging from 441– 479 °C in argon atmosphere.

Determination of ibuprofen and flurbiprofen in pharmaceuticals by capillary zone electrophoresis

Capillary zone electrophoresis with spectrophotometric detection was used for the determination of ibuprofen (IB) and flurbiprofen (FL) in pharmaceuticals. The separation was carried out in a fused silica capillary (60 cm × 100 μm i.d. effective length 45 cm) at 30 kV with UV detection at 232 nm. The optimized background electrolyte was 20 mM N-(2-acetamido)-2-aminoethanesulfonic acid (ACES) with 20 mM imidazole and 10 mM α-cyclodextrin of pH 7.3. 2-Naphthoxyacetic acid was used as internal standard. A single analysis took less than 5 min. Rectilinear calibration ranges were 2–500 mg l −1 for IB and 1–60 mg l −1 for FL. The relative standard deviations (R.S.D.) values ( n = 6) were 1.53% for IB and 1.29% for FL (for 200 mg l −1 IB and 10 mg l −1 FL). This validated method has been successfully applied for the routine analysis of 10 commercially available pharmaceutical preparations (syrup, tablets, cream and gel).

The development and comparison of a fluorescence and a phosphorescence optosensors for determining the plant growth regulator 2-naphthoxyacetic acid

We describe two luminescence methods based on a flow-through optical sensor. A fluorescence and a phosphorescence optosensors have been developed and compared. Both techniques are fast (response time of 150 and 90 s, respectively) and simple. The fluorescence optosensor is based on the on-line immobilization of 2-naphthoxyacetic acid (β-NOA) on a non-ionic resin (Amberlite XAD-7) solid support in a continuous-flow system (10 mM glycine/HCl buffer solution at pH 2.5) and the phosphorescence one on the on-line immobilization of β-NOA on silica gel solid support in a 175 mM TlNO 3 and 10 mM Na 2SO 3 continuous-flow system. Fluorescence and phosphorescence intensities were measured at λ exc/em = 328/348 and 276/516 nm, respectively. The fluorescence optosensor was sensitive to a linear concentration range of between 2.0 and 225.0 ng mL −1 with a detection limit of 2.0 ng mL −1 and a standard deviation of 2.8% at 125 ng mL −1, and for the phosphorescence a linear concentration range between 4.9 and 250.0 ng mL −1, a detection limit of 4.9 ng mL −1 and a standard deviation of 2.23% at 150 ng mL −1. Also, a study of applicability was carried out obtaining recovery percentages around 100% with standard deviations slower than 2.2%.

Specificity patterns indicate that auxin exporters and receptors are the same proteins.

A study of transport and action of synthetic auxin analogues can help to identify transporters and receptors of this plant hormone. Both aspects--transportability and action on growth--were tested with 2-naphthoxyacetic acid (2-NOA) and compared across several plant species. 2-NOA stimulates elongation effectively at low concentrations in petioles of the gymnosperm Ginkgo biloba L., in hypocotyls or internodes of the dicot legumes, mung bean (Vigna mungo L.) and pea (Pisum sativum L.), in cotyledons of onion (Allium cepa L.) and in leaf bases of chive (Allium schoenoprasum L.), the latter two of the monocot order Asparagales. In contrast, elongation of coleoptile segments of maize (Zea mays L.) is poorly responsive to 2-NOA. Significant auxin-like transport of 2-NOA was observed in segments of mung bean hypocotyls, pea internodes, and chive leaf bases, but not in segments of the grass coleoptiles. Thus, for the two assays, elongation and polar transportability, the same difference in ligand specificity was observed between the grass and all other species assayed. This finding supports the hypothesis that a common protein mediates auxin efflux as well as auxin action on elongation.

2-Amino-2-thiazoline and its 1:1 organic salt with 2-naphthoxyacetic acid.

The crystal structures of 2-amino-2-thiazoline, C3H6N2S, and 2-amino-2-thiazolinium 2-naphthoxyacetate, C3H7N2S+.C12H9O3-, are reported. The structure of 2-amino-2-thiazoline consists of two unique molecules that construct a convoluted hydrogen-bonded ribbon involving R(2)2(8) graph-set association via both N-H...N and N-H...S interactions. The organic salt structure consists of the two molecules associated via an R(2)2(8) graph-set dimer through N-H...O interactions, with the hydrogen-bonding network propagated via additional N-H...O three-centre interactions from the second 2-amine H atom.

Synthesis, Resolution, and Application of 2,2′‐Bis(diphenylphosphino)‐3,3′‐binaphtho[b]furan (BINAPFu).

AbstractFor Abstract see ChemInform Abstract in Full Text.

PRODUCTIVITY STIMULATION IN STRAWBERRY BY APPLICATION OF PLANT BIOREGULATORS

Influence of several plant bioregulators (PBRs) on yield and growth of strawberry plants in two field experiments was evaluated. Experiments were carried out at the Research Institute of Pomology and Floriculture, Skierniewice, Poland, in the years 1997-2000. In the first experiment conducted from 1997 to 1999 three cultivars (‘Senga Sengana’, ‘Dukat’ and ‘Elkat’) were sprayed 3 times during the blooming time with new formulations of preparations containing 2-naphthoxyacetic acid (BNOA) and/or gibberellic acid (GA3). It was found that the tested cultivars responded differently to the applied PBRs. ‘Senga Sengana’ responded positively, while ‘Dukat’ and ‘Elkat’ did not. Among evaluated bioregulators the best results were obtained after the application of Betoxon Super 050 SL (salt of 2-naphthoxyacetic acid with triethanolamine). It resulted in increased yield (by 31.9%) and improved fruit quality. Fruits from treated plants were larger (by 11.6%) and firmer than those from the control ones. Application of the PBRs had no influence on the degree of fruit infection with grey mould. The second experiment was carried out in 2000. Its aim was to stimulate the vegetative growth (determined by formation of runners and daughter plants) of three strawberry cultivars which are poor in forming runners and therefore difficult to propagate (‘Selva’, ‘Mara des Bois’ and ‘Vikat’) by application (three times in mid summer) of several PBRs. The following PBRs were applied: Pomonit Super 05 SL (5% triethanolamine salt NAA), Paturyl 100 SL (10% BA), Gibrescol 10 MG (10% GA3), Promalin 3.6 SL (1.8% BA + 1.8% GA4+7) and ASAHI SL (trade name Atonik – 0.3% sodium para-nitro-phenolan + 0.2% sodium orto-nitrophenolan + 0.1% sodium 5-nitrogujakolan) – each of them in concentrations of 0.1% and 0.2%. The most simulative effect on daughter plants formation was established for Gibrescol 10 MG (0.2%) and Promalin 3.6 SL (0.2%), results being quite similar for both preparations. These treatments increased the number of daughter plants by almost 300% as compared with the untreated control mother plants.

Synthesis, resolution, and application of 2,2′-bis(diphenylphosphino)-3,3′-binaphtho[b]furan (BINAPFu)

(±)-2,2′-Bis(diphenylphosphino)-3,3′-binaphtho[2,1-b]furan (BINAPFu) was synthesized from 2-naphthoxyacetic acid in a five-step sequence in 62% overall yield. A variety of reported resolution procedures for biaryl bisphosphines did not work with (±)-BINAPFu; thus, a new resolution method was developed, involving the Staudinger reaction of the aforementioned racemate of BINAPFu with an enantiopure camphor sulfonyl azide derivative. The resulting diastereomeric phosphinimines were separated by flash chromatography. Subsequent hydrolysis to the corresponding bis-phosphine oxide and trichlorosilane reduction provided enantiopure BINAPFu. The absolute stereochemical configuration of BINAPFu was established by X-ray crystallography. BINAPFu was compared with commercially available 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) in Pd(0)-catalyzed intermolecular Heck reactions. Investigation of the Heck arylation of 2,3-dihydrofuran showed BINAPFu to be more efficacious than BINAP in dioxane at 30 °C. A variety of phosphorus selenides were prepared, and the 1JP-Se coupling constants measured, to obtain a comparative scale of parent phosphine basicity. The phosphorus atoms in BINAPFu were found to be electron deficient when compared with BINAP but slightly more electron rich than trifurylphosphine. Key words: naphthofurans, atropisomers, electron-deficient phosphines, asymmetric Heck reactions, Staudinger reaction.

OVARY AS VALUABLE EXPLANT FOR SOMATIC EMBRYOGENESIS INDUCTION IN GRAPES (VITIS SPP.)

Somatic embryogenesis still needs to be improved for most agronomically important grapevine cultivars. Anthers are the explants generally used for grape somatic embryogenesis initiation, while ovaries are less frequently adopted. However, ovaries proved to be a suitable material for establishing somatic embryogenesis, as we obtained somatic embryos starting from these explants in several grape rootstocks (V. rupestris du Lot, Kober 5 BB, 110 Richter) and V. vinifera cvs. (Barbera, Brachetto a grappolo lungo, Chardonnay, Moscato bianco, Muller-Thurgau, Riesling). Flowers were collected in the vineyard 10 to 14 days before blooming, and both anthers and ovaries were plated on solid NN-based media added with 9 µM 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.4 µM 6-benzyladenine (BA) (Medium A), or with 4.5 µM 2,4-D and 8.9 µM BA (Medium B), or with 5 µM 2,4-D and 1 µM BA (Medium C). Embryogenic callus was obtained from both anther and ovary cultures, with different efficiencies depending on genotype, explant type and medium, in most cases ovaries giving better results than anthers. No difference was noted in any aspect between embryogenic cultures originated from the two floral explants. Stable embryogenic cultures were preserved during a two-step culture: in the first step, callus propagation was obtained on the medium containing 4.5 µM 2,4-D and 8.9 µM 6-benzyladenine; in the second step, development of somatic embryos was induced within an additional two-month culture on an embryo differentiation medium supplemented with 10 µM 2-naphthoxyacetic acid, 1 µM 6-benzyladenine, 20µM indole-3-acetic acid and 2.5 g.l-1 activated charcoal. Somatic embryo maturation and individualization was obtained in NN-based liquid medium with 0.5 µM indole-3-butyric acid, while embryo conversion into plants occurred at satisfactory efficiencies when isolated somatic embryos were cultivated on a NN-based solid medium with 4.4 µM 6-benzyladenine and 0.5 µM indole-3-butyric acid. Plant micropropagation was performed in hormone-free NN medium.