A simple protocol for mass multiplication of Crataeva nurvala, a medicinal tree, from seedling-derived explants is described. Six different types of explants (cotyledonary nodes, epicotyl nodes, hypocotyl segments, first pair of leaves, cotyledons, and root segments) developed shoots on Murashige and Skoog's (MS) basal medium or the same supplemented with different concentrations of 6-benzylaminopurine (BAP). Among the explants tested for caulogenic potential, only the epicotyl and cotyledonary nodal explants developed shoots on MS basal medium, while on BAP (0 - 2.0 mg dm^-3) adjuvated media all the explants exhibited caulogenesis. The optimum concentration of BAP varied for these explants. The shoots could be rooted on half strength MS with 0.02 mg dm^-3 α-naphthalene acetic acid to get plants, which have been transferred to soil. The explants from in vitro regenerated shoots also possessed a similar caulogenic potential.

Distribution of cadmium between roots and shoots of barley was manipulated by the cadmium concentration (0.01 and 0.005 mM Cd²⁺), pH (4.6 and 5.9) as well as treatment duration. The prolongation of treatment increased dry mass and content of cadmium in plants. The cadmium is accumulated mainly in roots. Presence of both, 0.005 mM Cd²⁺ and 100 mM NaCl in medium at pH 5.9 (Cd-NaCl plants) resulted in the most severe growth inhibition of plants, but about one half accumulation of cadmium in roots then in a case of only Cd-treated plants. In the Cd-NaCl plants, the net photosynthetic and transpiration rates were less reduced then in a case of only NaCl-treated plants. The treatments also influenced uptake of Ca, Cd, Cu, K, Mg, Na and Zn predominantly in roots.

A spontaneously embryogenic cell line of the coumarin producing angelica [Angelica archangelica (L.) subsp. archangelica] was established via callus formation from seedlings grown from sterilized seeds on semi-solid, hormone-free modified B5 medium. The cell line has retained its embryogenic capacity for 5 years. The highest coumarin production for the cell line after 3 weeks of cultivation was achieved in the medium containing 3.0 % sucrose. Jasmonic acid had no statistically significant effect on the biomass or coumarin production. The established embryogenic cell line could be stored using cryopreservation. Plantlets grown in an air-sparged bioreactor were transferred directly to soil and vermiculite, and 63 % of them grew to maturity through two growth seasons. The coumarin content in the regenerated plants was comparable to that in wild plants. Thus this cell line could be used for in vitro propagation.

Seasonal changes in foliage nitrogen (N) and carbon (C) concentrations and δ¹⁵N and δ¹³C ratios were monitored during a year in Erica arborea, Myrtus communis and Juniperus communis co-occurring at a natural CO₂ spring (elevated [CO₂], about 700 μmol mol^-1) and at a nearby control site (ambient [CO₂], 360 μmol mol^-1) in a Mediterranean environment. Leaf N concentration was lower in elevated [CO₂] than in ambient [CO₂] for M. communis, higher for J. communis, and dependent on the season for E. arborea. Leaf C concentration was negatively affected by atmospheric CO₂ enrichment, regardless of the species. C/N ratio varied concomitantly to N. Leaves in elevated [CO₂] showed lower δ¹³C, and therefore likely lower water use efficiencies than leaves at the control site, regardless of the species, suggesting substantial photosynthetic acclimation under long-term CO₂-enriched atmosphere. Leaves of E. arborea showed lower values of δ¹⁵N under elevated [CO₂], but this was not the case of M. communis and J. communis foliage. The use of the resources and leaf chemical composition are affected by elevated [CO₂], but such an effect varies during the year, and is species-dependent. The seasonal dependency and species specificity suggest that plants are able to exploit different available water and N resources within Mediterranean sites.

During germination and post-germinative growth of Pinus pinaster Ait. seeds, triglycerides are hydrolysed and concurrently the embryo accumulates starch. In this study, the spatio-temporal variation of starch accumulation was described in zygotic embryos associated (ZE⁺) or not (ZE^-) to their megagametophyte and in somatic embryos (SE). In germinating ZE⁺, starch was accumulated in the growing tissues, following closely the spatio-temporal pattern of triglycerides depletion. In contrast, in ZE^- and SE, starch was only found in cortical cells close to the culture medium. In germinating ZE⁺, the spatio-temporal variations of starch accumulation can be thus interpreted as the result of the changing contact between the megagametophyte and the growing tissues and also of the existing interactions between triglyceride hydrolysis and the allocation of sucrose exported from the megagametophyte.

Image analysis has become a powerful tool for the quantification of histochemical detections mainly in animal and medical sciences. There is not, however, much information about the accuracy of image analysis quantification of histochemical products and their comparison to biochemical analyses. Our study focused on the quantification of histochemically detected amounts of phenolic compounds, lignin and activity of peroxidases in the two youngest age classes of Norway spruce (Picea abies (L.) Karst) needles with the use of image analysis and its comparison with biochemical assays. The image analysis-determined amount of lignin and peroxidase activity was well correlated with its biochemical assay. On the other hand, no optical parameters of the reaction product of the histochemical reaction of phenolics correlated with the biochemical quantification. This proves that results of quantification of histochemical detection with image analysis greatly depend on the character and procedure of the histochemical proof. If it is done in full respect of the conditions of a histochemical reaction it can gain reliable and interesting results. Great advantage of the image analysis approach is quantification of the studied substance in different tissues within single sample as well as among different samples, which in many cases cannot be detected with biochemical tools.

The influence, was investigated, of abiotic parameters on the isolation of protoplasts from in vitro seedling cotyledons of white lupin. The protoplasts were found to be competent in withstanding a wide range of osmotic potentials of the enzyme medium, however, -2.25 MPa (0.5 M mannitol), resulted in the highest yield of protoplasts. The pH of the isolation medium also had a profound effect on protoplast production. Vacuum infiltration of the enzyme solution into the cotyledon tissue resulted in a progressive drop in the yield of protoplasts. The speed and duration of orbital agitation of the cotyledon tissue played a significant role in the release of protoplasts and a two step (stationary-gyratory) regime was found to be better than the gyratory-only system.

The cyanobacterial crust occurring in desiccated state exposed to high temperature and solar radiation on the rock surface contained several low molecular mass (LMM) proteins (10.5, 13, and 25 kDa), water stress protein (wsp, 39 kDa), additional proteins (43 and 49 kDa), a chaperonin (58 kDa), and a stress-induced protein (84 kDa). When the crust was exposed to UV-C radiation, it counteracted the UV-B damage by overproduction of certain proteins and synthesis of two high molecular mass (HMM) proteins. Exposure of the crust to heat had an adverse effect on the survival of the organism there-in which was due to repression of few proteins. Unlike the modification pattern of protein synthesis in the cyanobacterium inhabiting the crust, the same organism grown in culture could tolerate heat by synthesizing two HMM proteins. Several proteins of diverse groups were repressed in the cyanobacterium in culture upon exposure to UV-C, which was counteracted by induction of three new polypeptides (chaperonin and HMMs), and overproduction of one 41 kDa protein.

Electrophoretic patterns of glutamate oxaloacetic transaminase (Got) and malate dehydrogenase (Mdh) of Zea mays L. × Tripsacum dactyloides L. hybrids and their parents have been compared. The results suggested that Got and Mdh isozymes may be used as markers for genic regions on 5 S and 6 L maize chromosomes and for linkage groups D and L on T. dactyloides chromosomes, syntenic to genic regions on 5 S and 6 L maize chromosomes. The latter have a regulatory effect on fertility and on the apomictic mode of reproduction.

Transgenic rice plants harbouring Bacillus subtilis protoporphyrinogen oxidase (Protox) gene, which is targeted into plastid, were generated by Agrobacterium-mediated transformation using a rice (Oryza sativa L. cv. Dongjin) and their gene integration at T₁ generation by Southern and mRNA expression in T₂ generation by Northern blotting were analyzed. Their herbicide-resistant trait was further confirmed by in vitro leaf segment assay and in planta bioassays such as seed germination assay and measurement of growth inhibition. The herbicide oxyfluorfen resistance in transgenic rice plants was not very high. The results showed that the Protox from B. subtilis can not be applicable as a gene source to generate a high level oxyfluorfen tolerance in plants.

The alterations of organization of leaf tissues and cell ultrastructure as a consequence of salt stress (75 and 150 mM NaCl) were studied in two tomato (Lycopersicum esculentum Mill.) cultivars showing different salinity tolerance. The salinity brought changes in cell shape, volume of intercellular spaces and chloroplast number, shape and size. These characteristics were specific in each cultivar. The ultrastructural changes were also different in the two tomato cultivars studied and the most important ones were in the number and size of starch granules in chloroplasts, the number of electron-dense corpuscules in the cytoplasm, the structure of mitochondria, and number of plastoglobuli.

Exposure of groundnut seeds and seedlings to 25, 100, and 250 μM concentrations of jasmonic acid resulted in a reduction of germination percentage, growth, fresh mass, dry mass, chlorophyll content, chlorophyll stability index, proteins and an increase in free proline content and cell membrane injury. The results suggest the inhibitory effect of jasmonic acid on growth of the groundnut seedlings.

The effect of exogenous brassinosteroids (BR) on the flowering induction of Pharbitis nil was examined. Generally plants treated with brassinolide and castasterone form less number of flowers than control plants, but degree of flowering inhibition was depended on the concentration and the method of BR application as well as the length of the inductive dark period. In plants regenerated from sub-induced apices treated with brassinolide at concentration of 1 and 10 μM the flower formation was inhibited completely.

Treatment of intact potato (Solanum tuberosum L., cv. Nevskii) tubers with 24-epibrassinolide (EB) resulted in prolonged deep dormancy, increased production of ethylene and higher contents of free and bound abscisic acid (ABA) in buds. EB at the most efficient concentration 0.021 mg dm^-3, applied immediately after tuber harvest, inhibited sprouting by 36 - 38 d, increased ethylene formation after 1 and 7 d of storage by almost 300 and 150%, respectively, and increased the content of both free and bound ABA during the whole period of storage (on average by about 80%). Electron microscopic and morphometric studies showed that EB brings about a decrease in cell volume in tunica and all types of meristems and an increase in the number of vacuoles, accompanied by a decrease in their volume.

Rhizobacteria belonging to Bacillus sp. were isolated from the rhizosphere of green gram (Vigna radiata). Seed inoculation with the rhizobacteria showed stunting effect on root growth whereas four Bacillus strains caused stimulation of shoot growth at both 4 and 7 d of observations. Coinoculation of some Bacillus strains with effective Bradyrhizobium strain S24 resulted in enhanced nodulation and plant growth of green gram. The shoot dry mass (ratio to uninoculated control) varied from 1.32 to 6.33 at day 30 and from 1.28 to 3.55 at day 40 of plant growth. Nodule promoting effect after 40 d of plant growth was observed with majority of Bacillus strains except for MRS9 and MRS26. Maximum gains in nodulation, nitrogenase activity and plant growth were observed with Bacillus strains MRS12, MRS18, MRS22 and MRS27 after 40 d of plant growth, suggesting the usefulness of introduced rhizobacteria in improving crop productivity.

Effects of two cytokinin antagonists - 2-chloro-4-cyclobutyl-amino-6-ethylamino-1,3,5-triazine and N-(4-pyridyl)-O-(4-chlorophenyl)carbamate - on bud break and outgrowth in single nodes from two Rosa hybrida cultivars differing in their apical dominance were studied. The compounds were applied at three different concentrations separately or in combination with benzyladenine. Cytokinin antagonists reduced the number of the sprouted buds in both cultivars at different extent. Their effect was strongly dependent on both concentration applied and culture period duration. The replacement of anticytokinins with benzyladenine in the medium resulted in overcoming of the bud break suppression. Both compounds significantly inhibited bud outgrowth as well.

Treatment of rose shoots with 50 µM acibenzolar-S-methyl (BTH) resulted in increased protection against Diplocarpon rosae. This was accompanied by the induction and accumulation of a set of extracellular proteins as shown by SDS-PAGE and 2D-PAGE. Some of these proteins have been identified as PR-1, PR-2, PR-3 and PR-5 proteins by immunoblot analysis probed with tobacco antisera against PR-1c, PR-N, PR-Q and PR-S protein. Most of the extracellular proteins activated by BTH were also induced and found to accumulate in leaves upon infection with Diplocarpon rosae. However, their accumulation was much more pronounced in BTH-pretreated leaves than in water-pretreated leaves upon a challenge inoculation with D. rosae, particularly, the 15 kD PR-1, 36 and 37 kD PR-2 proteins. They may be more important in the expression of disease resistance.

A study was conducted to evaluate in vitro techniques for germplasm preservation of wild species of Arachis. Nodal segments excised from in vitro-grown plants of A. retusa, A. macedoi and A. burchellii were used to examine the effects of explant position and age of the donor plant. Explants were excised from plants maintained in culture for 30, 60, 90 or 180 d, numbered I - V from top to bottom and cultured on MS medium supplemented with 2.7 µM NAA or different BAP concentrations (0, 4.4, 13.2 and 22 µM). The age of the donor plant has not influenced the responses of the four genotypes studied. In contrast, shoot regeneration ability was significantly affected by the original explant position, decreasing from top to bottom. In media supplemented with different BAP concentrations, multishoot formation was induced from apical segments at low frequencies (10 - 20%) and segments of all positions originated calluses at the explant basis after 30 d of culture. The culture of nodal segments in the presence of 2.7 µM NAA as the sole growth regulator is recommended for the multiplication of in vitro collections of wild groundnut species in order to avoid callusing and adventitious shoot formation.

Phenolic compounds from leaves and roots of infected and healthy cocoyam clones resistant (RO1075), tolerant (RO1043), and susceptible (RO1157) to Pythium myriotylum were quantified and tested for their in vitro fungitoxicity on the causal agent of the cocoyam root rot disease. All clones, infected or not, have phenolic compounds showing fungitoxic activity. The phenolic content of the tolerant and susceptible clones is less than that observed in the resistant one meanwhile in the resistant clone RO1075, a large increase in phenolic content is observed particularly in the roots during attack by pathogen.

Effects of four culture media on callus induction, regeneration and number of plants per unit culture were studied with mature seeds from five indica rice genotypes as explants. Based on the morphology, the calli were classified into four types as I to IV. Type I and type II are most suited to initiate suspension cultures or as target material for transformation. Number of plants regenerated per unit culture, formation of easily dissociating cell clusters and frequency of type I and type II calli were highest on NBKNB medium. Thus NBKNB medium is suitable for in vitro culture of even the hitherto recalcitrant indica genotypes.

The salicylic acid-induced changes in the polypeptide patterns of barley (Hordeum vulgare L.) leaves have been analysed using two-dimensional gel electrophoresis. An optimized 2-D PAGE protocol was used and gave reproducible 2-D gels from leaf crude protein extracts with a high number of detected polypeptides. When applied for 24 h SA affected the expression of a number of soluble proteins. Most of them appeared to be down-regulated. Although no abundant expression of specific proteins was observed, we detected three polypeptides that were present only in SA-treated leaves.

Somatic embryogenesis in pigeonpea [Cajanus cajan (L.) Millsp.] has been achieved using cotyledon segments of mature seeds as explants. A large number of globular somatic embryos were induced directly from cotyledons of genotypes T-15-15, GAUT-82-90 and GAUT-82-99 when cultured on EC6 basal medium supplemented with 2.22, 4.44, 13.32 or 22.2 μM N⁶-benzylaminopurine (BAP) and 0.45, 1.36, 2.27, 4.54 and 13.62 μM thidiazuron. Somatic embryos developed into cotyledonary stage when the globular embryos were transferred to Murashige and Skoog's (MS) basal medium containing 2.89 - 14.43 μM gibberellic acid. Maturation of somatic embryos was achieved on half strength MS medium with 0.38 μM abscisic acid. The mature somatic embryos were germinated on MS medium supplemented with 0.44 μM BAP and the plantlets were hardened and transferred to soil.

Accelerated ageing of Dendrocalamus strictus Ness seeds at 42 ± 1°C and 100% relative humidity for 1 to 8 d was conducted. Seeds lost viability and changed their biochemical constituents. Reductions in the contents of sugars, starch, proteins and lipids were found. Decrease in the activity of the peroxidase as well as acid and alkaline phosphatase were also observed. Increase in total free amino acids content and the activity of amylase confirmed the degradation of seed reserves.

The influence of nitrogen deprivation on leaf development and the biomechanics of leaf growth were studied using maize (Zea mays L.) seedlings grown under low irradiance. Although the nitrogen deprivation had no significant effect on photosynthesis, the leaf length, the leaf area, and the total assimilation area of plants decreased. The mature size of the epidermal cells was not altered, while the cells of nitrogen-deprived plants reached their final length closer to the leaf base than the epidermal cells of control plants. Decreases in the length of the growing zone (from 50 to 30 mm) and in the maximum value of relative elemental growth rate (from 0.08 to 0.06 mm mm^-1 h^-1) were observed in the nitrogen deprived plants. The maximal value of growth velocity in the control treatment was higher along the elongation zone, except for the basal 20 mm, where there was no significant difference between the control and the N-deprived plants. The net deposition rates of water and dry matter were also affected by nitrogen deprivation: the values of these features decreased and the spatial position of the maximum of the deposition rates shifted towards the leaf base.

A set of 28 fibre flax and linseed cultivars differing in plant morphology and technological parameters were analysed by isozyme markers in five ontogenetic phases. Relatively high isozyme polymorphism was observed using polyacrylamide gel electrophoresis. Altogether 18 isozyme systems produced 145 different bands; 66 of them (45.52 %) have been found to be polymorphic. The highest level of polymorphism was found in acid phosphatase and esterase, polymorphism was detected in aconitase, diaphorase, glutamate dehydrogenase, peroxidase and superoxide dismutase as well. The highest number of unique isozymic spectra (cultivar × enzyme × ontogenetic phase) was detected in the phase of shoot with removed cotyledons. Electrophoretic analysis of all polymorphic isozymes enabled to distinguish 20 cultivars (71 %) in the screened cultivar set.

The seasonal dynamics in content and distribution of N-rich compounds between overwintering organs of Calamagrostis epigeios were examined. Samples were taken both from plants grown in natural conditions and in containers with controlled nutrient supply. There were significant changes in content of nitrate, free amino acids and soluble protein in all investigated plant parts during the course of a year. Amino acids showed both the highest maximum and seasonal fluctuation among the all N compounds observed and, therefore, appear to have a central role in N storage. Their content rises in the autumn, remains stable during winter and declines quickly at the beginning of spring. The most abundant amino acids in the end of winter storage period - asparagine, arginine and glutamine - constituted about 90 % of N in fraction of free amino acids. The portion of N stored in soluble proteins, however, was considerably smaller compare to both amino acids and nitrate. The amount of N stored in rhizomes of C. epigeios was smaller than in roots and stubble base before the onset of spring re-growth. This indicates that roots and stubble base are particularly important for winter N storage in this species.