In vitro propagation of Asparagus maritimus – A rare Mediterranean salt-resistant species

Asparagus maritimus L. Miller is a rare species growing of the Mediterranean region and is morphologically similar to A. officinalis. In order to establish an efficient in vitro propagation protocol, explants were excised from spear segments and cultured on Murashige and Skoog (1962) medium containing 3% sucrose and various concentrations of growth regulators. The best shoot initiation (3–4 per explant) was achieved on a medium containing 0.88 M N⁶-benzyladenine (BA), 0.93 M kinetin, 1.07 M -naphthaleneacetic acid (NAA) and 3.90 M ancymidol. Shoot initiation could also be achieved without ancymidol but the shoots were thinner and longer. A very high shoot multiplication rate was achieved on media supplemented with 3% sucrose, 1.07 M NAA, 0.93 M kinetin, 0.44 M BA and various concentrations of ancymidol. The lowest concentration of ancymidol (0.39 M) significantly promoted the highest shoot multiplication rate (11.9 shoots/crown). For root formation, media were supplemented with 6% sucrose, 1.07 M NAA and various concentrations of ancymidol. Rooting frequency increased with higher ancymidol concentration up to 5.07 M (82.0% rooting). The number of ex vitro shoots formed was strongly correlated (r=0.66) with the length of roots formed in vitro, which was the highest at a 1.95 M ancymidol.     

Über Aktivitätssteigerungen der Pyruvatkinase durch Blaulicht oder Glucose bei einer chlorophyllfreien Chlorella-Mutante

Summary Crude extracts of dark-kept resting cells of a chlorophyll-free, carotenoid-containing mutant of Chlorella vulgaris Beijerinck (211-11h/20) were found to convert 14.44±0.77 nmol PEP per min and mg protein into pyruvate by the action of pyruvate kinase (=PK; EC 2.7.1.40). When such cells were exposed to blue light (<550 nm, 300 W cm^-2) for 3 hrs the PK-activity/protein of their crude extracts rose to 21.47±1.30, i.e., it was enhanced by 43%. Poisoning with 10^-3 mol cycloheximide or with 150 g actinomycin D/ml prevented the effect of blue light by 80–90% (Table 1). This result points to an induction of enzyme synthesis in blue light. Addition of 1% glucose in the dark resulted in an increase in PK-activity, too. Three hrs after application of glucose the PK-activity was 28.05±1.88 nmol/min and mg protein, which was 94% greater than in the control. The effect of glucose was also largely preventable by cycloheximide (10^-3 mol) or by actinomycin D (150 g/ml) (Table 2). These results lead to the conclusion that blue light may induce the synthesis of PK by supplying free sugars at the site of enzyme synthesis. The assumption is supported by the observation that in hot water extracts of blue illuminated cells in which glucose oxidation had been poisoned by. 10^-2 mol monoiodoacetic acid there was 60% more glucose, glucose-6-phosphate, fructose-6-phosphate and sucrose detectable than in extracts of equally poisoned algae from darkness (Table 3). It is suggested that blue light activates a system for the transport of sugar out of the chloroplast, which results in the induction of respiratory enzyme synthesis and thus in enhanced respiration.

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Abkürzungen PK Pyruvatkinase (EC 2.7.1.40) - PEP Phosphoenolpyruvat - LDH Lactatdehydrogenase     

Regeneration of plantlets through organogenesis in the Himalayan yellow poppy,Meconopsis paniculata

Plantlet formation through organogenesis in callus cultures of Himalayan yellow poppy,Meconopsis paniculata D.Don (Prain), a threatened taxon of ornamental value, is described. Hypocotyl segments from 3-month-old laboratory-raised seedlings produced callus on agar-solidified Murashige and Skoog medium (MS) containing 10 M -naphthaleneacetic acid and 1 M kinetin. Shoots differentiated best from callus on MS containing 10 M indolebutyric acid (IBA) and 1 M 6-benzyladenine. The regenerated shoots rooted best on MS medium containing 10 M IBA. From seed germination to differentiation of plantlets through the two-step organogenesis process required 28–29 weeks.Abbreviations 2,4-d 2,4-dichlorophenoxyacetic acid - FAA formalin-acetic acid-alcohol - BA 6-benzyladenine - IAA indole-acetic acid - IBA indolebutyric acid - GA₃ gibberellic acid - NAA -naphthaleneacetic acid - RH relative humidity     

Direct somatic embryogenesis through thin cell layer culture in Panax ginseng

Direct somatic embryos were differentiated on cotyledon transverse Thin Cell Layers (tTCLs) of Panax ginseng after 9 weeks in the Murashige and Skoog basal (MS) medium containing 2,4-d (5M). When MS medium containing 2,4-d (5M) was used for seedling pretreatment and for tTCLs culture, somatic embryos were observed 2 weeks earlier, i.e. after 7 weeks of culture. On the tTCLs from seedlings pretreated with 2,4-d (5M) combined with benzyladenine and zeatin at 0.1 M (BZ), somatic embryos were observed after 6 weeks of culture and the percentage of embryogenesis was higher (62%) than when 2,4-d was used alone for pretreatment (40%). Similar results were also obtained from pretreatment with combinations of 2,4-d (5M) and thidiazuron (TDZ) (0.01, 0.1M). When a combination of 2,4-d (5M) and BZ (0.1M) was used both for seedling pretreatment and for tTCLs culture, both somatic embryos and shoots were observed after only 3 weeks. As the concentration of BZ increased, the percentage of somatic embryogenesis decreased but the percentage of organogenesis increased. Similar responses were obtained with a combination of 2,4-d (5M) and TDZ (0.01M). On the medium containing both NAA (0.3M) and BZ (1M), globular- and heart- stage embryos developed after 4 weeks of culture into cotyledonary-staged embryos which remained dormant after a short elongation of the embryo axis. The importance of seedling pretreatment by growth substances in enhancing somatic embryogenesis is reported.Abbreviations BA 6-benzyladenine - BZ combination of BA and zeatin - 2,4-d 2,4-dichlorophenoxyacetic acid - MS medium Murashige and Skoog basal medium - NAA a-naphthaleneacetic acid - TDZ thidiazuron - tTCLs transverse thin cell layers - TCL longitudinal thin cell layer     

Axillary shoot induction and plant regeneration in Plantago ovata Forssk

Axillary shoot induction and plant regeneration were obtained in Plantago ovata. The optimum medium for inducing axillary shoots was Murashige & Skoog (MS) medium [5] supplemented with 4.6 M kinetin and 0.05 M NAA. Rooting of shoots was best on half-strength MS medium containing 5.0 M IBA and 0.05 M kinetin. The regenerated plants were similar to the control plants in karyotypic and phenotypic details.     

Adventitious in vitro plantlet formation from immature floral stems of Crinum macowanii

Adventitious shoots and plantlets were regenerated in vitro from floral stem explants of Crinum macowanii (Bak.) (bush lily). The length (age) of the floral stem as well as the orientation and position of the explant disc in the floral stem were the most important factors affecting shoot regeneration. The highest number of shoots were regenerated when immature floral stems of 70–100 mm were used as starting material, using the middle or basal parts of the stem, and orientating the discs with their proximal ends on the medium. Combinations of kinetin (4.65 M) and either indoleacetic acid (0.57 M) or naphthaleneacetic acid (0.54 M), or a combination of benzyladenine (4.44 M) and 2,4-dichlorophenoxyacetic acid (0.45 M) resulted in the highest numbers of shoots being regenerated. Although a slight degree of callus formation was noticed on the cut-edges of the discs, shoot formation did not occur via callus, but directly from the floral stem epidermis. Unrooted shoots were rooted on MS-medium containing 0.17 M sucrose.Abbreviations BA benzyladenine - IAA indoleacetic acid - IBA indolebutyric acid - NAA naphthaleneacetic acid - 2,4-d 2,4 dichlorophenoxyacetic acid     

In vitro comparison of ceftazidime,aztreonam, cefpirome,gentamicin, imipenem,enoxacin, and ticarcillin plus clavulanic acid against 108 strains ofPseudomonas maltophilia

Pseudomonas maltophilia is an uncommon cause of hospital-acquired infection and is resistant to most of the antimicrobial agents used in the treatment of gram-negative infections. Susceptibility of 108 isolates ofP. maltophilia to ceftazidime, aztreonam, defpirome, gentamicin, imipenem, enoxacin, and ticarcillin plus clavulanic acid was determined by an agar dilution method. The isolates were in general resistant to the antibiotics. Imipenem and cefpirome were not active at clinically achievable levels. Of the isolates, 20% were susceptible to 16 g/ml ceftazidime, 53% were susceptible to 4 g/ml enoxacin, 10% were susceptible to 4 g/ml gentamicin, and 25% were susceptible to 64 g/ml ticarcillin plus 2 g/ml clavulanic acid.     

Sucrose in storage media and cultivar affects post-storage regrowth of <Emphasis Type="Italic">in vitro</Emphasis> Hosta propagules

The goal of this research was to investigate if culturing in high sucrose (5%) liquid media during multiplication phase (stage II) would enhance endogenous sugar levels and dry matter sufficiently to allow storage of in vitro plants in sugar free media without adversely affecting post-storage recovery. Hosta tokudama Newberry Gold (NBG) and Hosta Striptease were cultured in Murashige and Skoog (MS) media containing 5% sucrose during stage II and transferred to rooting phase (stage III) in MS medium without (0%) sucrose or with 3% sucrose for 4weeks. At the end of stage III, cultures were stored, with the remaining media, at 10°C with 5molm^–2s^–1 photosynthetic photon flux (PPF) from cool white fluorescent lamps for 7 or 14weeks with or without a 2-week dark period prior to removal from storage. In both cultivars, stage III plants cultured in 3% sucrose media had higher soluble sugar levels and greater shoot and root biomass than those cultured in 0% sucrose media. Shoot and root soluble sugars decreased during storage. Shoot growth ceased during storage in both media. Root dry matter continued to increase in plants stored in 3% sucrose media but did not change in 0% sucrose media. Plants cultured in 3% sucrose media had less leaf chlorosis and less mortality after 7 or 14weeks of low temperature storage than the plantlets from sugar free media. Extending the storage period from 7 to 14weeks or introduction of 2-week dark period at the end of storage did not affect leaf chlorosis or plant mortality during acclimatization. Post-storage growth varied with the cultivar. Benefit of having sucrose in storage media was to develop a strong root system that aided the acclimatization and post-storage growth following 7 or 14week storage. Sucrose loading by culturing plants in liquid media containing 5% sucrose did not allow storage in sugar free media without adversely affecting post-storage growth in both cultivars.     

Feeding in the rotifer Brachionus calyciflorus

Summary The laboratory feeding behavior of Brachionus calyciflorus varies depending upon the type of food cell available in suspension. When feeding on the yeast Rhodotorula glutinis, rotifers show a continuous increase in ingestion with increased cell density between 0.01 and 1000 g dry weight ml^-1. Effective clearance rates drop from ca. 50 l animal^-1 h^-1 to less than 0.5 l animal^-1 h^-1 over this food density range. When feeding on Englena gracilis, B. calyciflorus ingestion rates are constant between 1.0 and 100 g ml^-1 of available food, averaging close to 25 ng animal^-1 h^-1. The decrease in clearance rate is more striking than with R. glutinis, dropping from 45 l animal^-1 h^-1 at 0.1 g ml^-1 to 0.13 l animal^-1 h^-1 at 100 g ml^-1. Differences between the patterns obtained with the two food types indicate fundamental dissimilarities in the feeding behavior of this rotifer species when presented with these different foods.     

Phenylacetic acid-induced somatic embryogenesis in cultured hypocotyl explants of geranium (Pelargonium x hortorum Bailey)

Summary The effect of a non-indole compound, phenylacetic acid (PAA), on the induction of somatic embryogenesis in tissue cultures of geranium (Pelargonium x hortorum Bailey cv. Scarlet Orbit Improved) was investigated. Hypocotyl explants derived from young, dark-grown seedlings were cultured on Murashige and Skoog (1962) medium (MS) supplemented with PAA or IAA (0.01–120 M) alone or in combination with BAP (8 M). Somatic embryogenesis was induced by both PAA and IAA at 0.01–20 M with 8 M BAP, however, the optima differed considerably for the two compounds. Maximal activity of IAA for somatic embryogenesis was found at 0.1–2.5 M, whereas PAA gave best results at 10 and 20 M under identical culture conditions. Higher concentrations (30–120 M) of IAA or PAA in the medium induced callusing in the explants, but the callus was neither embryogenic nor morphogenic.Abbreviations BAP N⁶-benzylaminopurine - IAA indole-3-acetic acid - MS Murashige and Skoog (1962) - PAA phenylacetic acid     

Morphology and structural organization of spiracles in femaleArgas (Persicargas) walkerae (Acari: Argasidae)

Scanning electron microscopical investigations of fractures and corrosion casts of the spiracles from femaleA. walkerae ticks revealed a four-part structure, consisting of spiracular plate, ostium and macula forming the external closure, followed by the subostial space and the vestibulum of regulable volume, as well as the atrial chamber as the innermost part from which the main tracheal trunks originate. On the average, the spiracular plate was 158 m long and 188 m at the broadest width. It consisted of a thin, highly perforated external and a thick internal layer, which enclosed the interpedicellar space with numerous stout pedicels. In its posterior region, the spiracular plate was covered by the macula, which was up to 80 m in length and 110 m in width. The interpedicellar cavity opened into the subostial space measuring 95.5 m in length and 159.6m in width, which proceeded into the 112-m long vestibulum. The roof of the vestibulum was flexible and could be everted and inverted. Inverted, the roof formed a quadratic bulge with numerous deep cuticular folds, which confined the lumen of the vestibulum either partially or completely. In corrosion casts, the roof was everted to a length of up to 89.3 m. In the posterior part of the vestibulum, as well as in the initial fourth of the artrial chamber, numerous anvil-, cone-or drop-like cuticular projections were arranged in wedge-like fashion. The atrial chamber was almost spherical with a diameter of 138.4 m. Five main tracheal trunks of different luminal diameter as well as numerous channels opened into the atrial chamber.     

Micropropagation ofPrunus mume

Shoot proliferation from axillary buds ofPrunus mume Sieb. et Zucc. was obtained on Woody Plant Medium (WPM) supplemented with 1 to 5 M benzyladenine, 3% sorbitol and solidified with 0.5 to 0.7% agar. Effects of different carbon sources on shoot proliferation were examined. Glucose provided better shoot proliferation than sucrose, sorbitol and fructose. In the presence of sucrose, leaf chlorosis occurred and shoots gradually declined. Best rooting percentage was obtained on WPM supplemented with 1 M naphthaleneacetic acid. Rooted plantlets were acclimatized under intermittent mist. However, survival rate was relatively low (20 to 30%).     

Single cell protein from pineapple cannery effluent

Candida utilis was grown on pineapple cannery effluent as the sole carbon and energy source. These effluents are rich in microbially utilizable nutrients. The principal sugars in the effluent were glucose, fructose and sucrose, and when supplemented with diammonium hydrogen phosphate to prevent nitrogen limitation they supported good growth. The maximum specific growth rate (m=0.46h–1) and cell yield coefficient (Yc/s=0.30) were obtained with 23.2 g carbohydrate/l in the growth medium. The values of m and Yc/s varied with carbohydrate concentration: higher values of m and Yc/s were obtained with lower concentrations of carbohydrate, suggesting that a chemostat would be more suitable for single cell protein production. Freeze-dried yeast contained 55.3, 51.2, 1.45, 6.4 and 27.4% of crude protein, true protein, DNA, RNA and carbohydrate respectively. The yeast had a balanced amino acid profile, except for sulphur-containing amino acids. A 90–95% reduction in the chemical oxygen demand of the effluent was achieved during this process which suggests that yeast may be effectively used to treat this waste.     

Effect of Cadmium on Soluble Sugars and Enzymes of their Metabolism in Rice

The effect of cadmium on the content of starch and sugars, and changes in the activities of the enzymes of sugar metabolism were studied in growing seedlings of rice (Oryza sativa L.) cultivars Ratna and Jaya. During a 5- to 20-d exposure at 100 M or 500 M Cd(NO₃)₂ in the growth medium an increase in the content of total soluble sugars and reducing sugars, and decrease in the content of non-reducing sugars was observed. Cd-induced increase in the sugar content was greater in shoots than in roots. No definite pattern of changes in starch content or in -amylase activity was observed. Presence of 100 or 500 M Cd(NO₃)₂ increased the activities of sucrose degrading enzymes, acid invertase and sucrose synthase, whereas the activity of sucrose phosphate synthase declined.     

Zur Feinstruktur der Elektrozeptorepidermis der Mormyridae (Teleostei,Pisces)

Zusammenfassung Die schwachelektrischen Mormyridae haben eine dreischichtige Epidermis, deren innere Schicht aus nur etwa 0,22 m dicken sechseckigen Zellen von ca. 60 m Durchmesser besteht. Die etwa 2 m dicken, linsenförmigen Kerne von 7,6 m Durchmesser liegen am Zellrand. Die Zellen sind zu Säulen aufgeschichtet. Ihr Rand ist ausgezackt und dort, wo er die Säulengrenze erreicht, auf etwa 0,34 m verdickt. In der Nähe der Säulengrenzen sind die Zellen über Desmosomen mit den Nachbarn in der eigenen und in der angrenzenden Säule verbunden. Diese Epidermisschicht ist auf die Körperpartien beschränkt, in denen auch Elektrorezeptoren ausgebildet sind.Die beiden anderen Epidermisschichten haben den üblichen Aufbau einer Fischepidermis, abgesehen vom Fehlen der Becherzellen.

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Ultrastructure of the electroceptor epidermis of the Mormyridae (Teleostei, Pisces)

Summary The weakly electric fish of the family Mormyridae have a three layered epidermis, with a medium layer consisting of hexagonal cells of only 0.22 m in thickness and about 60 m in diameter. The lens-shaped nuclei are about 2 m thick and 7.6 m in diameter and are situated near the border of the cells. The cells are piled up to hexagonal columns. Their margin is serrate and where it reaches the boundary of the column, it has a thickness of about 0.34 m. Close to the boundaries of the columns, the cells are linked to their neighbours within the column and of the adjoining column by desmosomes. This layer of the epidermis is confined to those regions of the body surface which also contain electroreceptors.The other layers of the epidermis have a structure as usual in fish, except for the lack of goblet cells.

     

Effect of mercuric chloride on carbon mineralization in soils

Summary The short and long-term effects of mercuric chloride amendment of five surface soils from southeastern Montana on carbon mineralization was studied. Short-term radiorespirometric studies utilizing a glucose substrate indicated Hg levels greater than 40 g/g soil were required for significant inhibition in all soils tested. Under chronic exposure conditions, levels from 0.1 to greater than 100 g Hg/g soil proved necessary for inhibition.     

Germination of Pistacia vera L. pollen in liquid medium

Summary The osmotic effect of Polyethylene glycol (PEG) has been shown to be sufficient to induce the germination of Pistacia vera L. pollen in liquid medium. The prehydration of the pollen in a saturated atmosphere for approximately 10 h was necessary to obtain maximum in vitro germination. Imbibition of the pollen in water resulted in the rapid leakage of solutes into the medium. These solutes consisted of approximately 50% carbohydrates, of which sucrose (0.65 mol/mg), glucose (0.77 mol/mg) and fructose (0.78 mol/mg) were the major sugars; the remaining 50% comprised proteins with the following major molecular weights 63 kDa, 60 kDa, 59 kDa, 40 kDa, 36 kDa, 35.5 kDa, 31 kDa, other organic matter and minerals.     

Die Länge der Internodien der Markfasern im Bereich der Sehrinde der erwachsenen Katze

Zusammenfassung Die Internodienlänge der Markfasern und ihre Abhängigkeit vom Durchmesser wird durch indirekte Messungen an elektronenmikroskopischen Bildern bestimmt. Der Ranviersche Schnürring wird für die Messung in einen nackten und zwei lamellierte Teile unterteilt (Abb. 1). Die Summenlänge der Markfasern und der Nodien besitzen die in Abb. 4 sichtbare Beziehung zum Durchmesser. Die Internodienlänge beträgt für Markfasern mit einem Durchmesser von 0,4 etwa 40 für solche mit einem Durchmesser von 2,5 etwa 500 . Es wurde eine mittlere Internodienlänge von 90 gefunden. Die Länge aller Markfasern pro mm³ beträgt 590 m; daraus kann eine Anzahl von 6 bis 7 Millionen Ranvierscher Schnürringe pro mm³ errechnet werden. Die Internodienlänge und der Durchmesser stehen wahrscheinlich in einer logarithmischen Beziehung (Abb. 8). In diese logarithmische Beziehung fügen sich die Ergebnisse anderer Autoren gut ein.

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Summary In electron micrographs the internodal length of myelinated fibers and its relation to the diameter has been measured. In this investigation the node of Ranvier is subdivided in three parts, i. e. one non-myelinated and two lamellated parts (Fig. 1). The relationship between the length of the nodes of Ranvier and its diameter is determined (Fig. 4). The internodal length is about 40 for fibers with a diameter of 0.4 and 500 for those with a diameter of 2.5 . The average internodal length is about 90 . The myelinated fibers have a total length of 590 m per mm³; in one mm³ there are therefore 6 to 7 million nodes. The relation between length of internodium and diameter of fiber is probably logarithmic (Fig. 8). The results are compared with similar measurements on peripheral nerves carried out by other authors.

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Mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Somatic embryogenesis in callus cultures of Rosa hybrida L. cv. Landora

Callus was initiated from immature leaf and stem segments of rose (Rosa hybrida cv. Landora) and subcultured every four weeks on a basal medium of half-strength Murashige & Skoog (1962) salts plus 30 g l^-1 sucrose (1/2 MS) and supplemented with 2.2 M BA, 5.4 M NAA and 2.2–9.0 M 2,4-D. Embryogenic callus and subsequently somatic embryos were obtained from 8-week-old callus culture on 1/2 MS+2.2 M BA+0.05 M NAA+0.3 M GA₃+200–800 mg l^-1 L-proline. Long-term cultures were established and maintained for up to 16 months by repeated subculture of embryogenic callus on L-proline deficient medium. About 12% of cotyledonary stage embryos taken from cultures cold-stored at 8±1°C for 4 days germinated on 1/2 MS+2.2 M BA+0.3 M GA₃+24.7 M adenine sulphate.Abbreviations BA benzyladenine - NAA -naphthaleneacetic acid - 2,4-D 2,4-dichlorophenoxyacetic acid - GA₃ gibberellic acid     

Significance of phosphoglucose isomerase for the shift between heterolactic and mannitol fermentation of fructose by Oenococcus oeni

The bacterium Oenococcus oeni employs the heterolactic fermentation pathway (products lactate, ethanol, CO₂) during growth on fructose as a substrate, and the mannitol pathway when using fructose as an electron acceptor. In this study, [U-¹³C]glucose, [U-¹³C]fructose, HPLC, NMR spectroscopy, and enzyme analysis were applied to elucidate the use of both pathways by the hexoses. In the presence of glucose or pyruvate, fructose was metabolized either by the mannitol or the phosphoketolase pathways, respectively. Phosphoglucose isomerase, which is required for channeling fructose into the phosphoketolase pathways, was inhibited by a mixed-type inhibition composed of competitive (K _i=180 M) and uncompetitive (K_i=350 M) inhibition by 6-phosphogluconate. Erythrose 4-phosphate inhibited phosphoglucose isomerase competitively (K _i=1.3 M) with a low contribution of uncompetitive inhibition (K_i=13 M). The cellular 6-phosphogluconate content during growth on fructose plus pyruvate (<75 M) was significantly lower than during growth on fructose alone or fructose plus glucose (550 and 480 M). We conclude that competitive inhibition of phosphoglucose isomerase by 6-phosphogluconate (and possibly erythrose 4-phosphate) is responsible for exclusion of fructose from the phosphoketolase pathway during growth on fructose plus glucose, but not during growth on fructose plus pyruvate.