Food-chain relationships in subtidal silty sand marine sediments and the role of meiofauna in stimulating bacterial productivity

Summary From bibliographic data the biomass correlations (organic dry weight) are constructed for the subsurface layer of a hypothetical 30 m deep silty sand station: 200 g/ml macrofauna (including 120 g/ml subsurface deposit feeders), 50 g/ml meiofauna, 20 g/ml Foraminifera, 1 g/ml Ciliata and Flagellata, and 100 g/ml bacteria. ATP-biomass is discussed.Meiofauna and Foraminifera contribute with 30 and 12% to the living biomass in the sediment, and it is assumed that their contribution to the food of deposit-feeding macrofauna is of a similar percentage. This is corroborated by productivity estimations.Bacteria are the main food of deposit feeding macrofauna, meiofauna, and microfauna. From different calculations it becomes evident that the productivity of bacteria in the sediment is far below figures achieved in experimental cultures: the conclusion is that sediment bacteria, in general, do not live under good environmental conditions.A rather large part of the bacterial population in the sediment seems to be in the stationary phase of life, and only a fraction of the total population exhibits high metabolic rates and rapid duplications. Only these active bacteria are of importance for the breakdown of relatively refractive organic matter in the sediment.In soft bottom marine sediments where the input of organic matter is higher than the remineralization rate, benthic animals stimulate by their activities and by nutrient cycling the decomposition of detritus via bacteria. Though meiofauna, in principle, feeds upon the same food resource as macrofauna, there is no real competition for food, because meiofaunal animals by their activities and by excreting metabolic end products induce a bacterial productivity which would not be there without them, and feed on it. There are a few examples where more specialized interactions exist between benthic animals and bacteria; these interactions have been termed gardening. They could be highly important in the benthic ecosystem.     

Effects of trichloroethylene,tetrachloroethylene and dichloromethane on enzymatic activities in soil

Summary Enzyme assays for -glucosidase, -acetylglucosaminidase, phosphatase, phosphodiesterase, and proteinase were made in soil samples incubated for two months after contamination with trichloroethylene, tetrachloroethylene, and dichloromethane. These volatile chlorinated hydrocarbons were added at doses of 10, 100, and 1000 g per 100 g dry soil, respectively. Almost no effect was observed in soil sample contaminated with 10 g of the chemicals when compared with control soil. When 100 g of the volatile chlorinated hydrocarbons was added, the activity of -glucosidase, -acetylglucosaminidase and, in part, also of proteinase, was reduced during the first 28 days of incubation but returned to the same or slightly higher level than in the control soil after 2 months. Trichloroethylene, tetrachloroethylene, and dichloromethane at a concentration of 1000 g per 100 g soil primarily inhibited activity of all enzymes under test. However, after two months, the enzymatic activities especially in soil samples contaminated with tetrachloroethylene and dichloromethane were found to be at the same or higher level than in the control soil.     

Saccharomyces cerevisiae 2-mum DNA. An analysis of the monomer and its multimers by electron microscopy.

Summary The non-tandem inverted duplication in the 2-m DNA of Saccharomyces cerevisiae has a length of 0.19 m and is located asymmetrically along the molecule. The majority of the dumb-bell structures that are formed upon denaturation and selfannealing of the 2-m monomer consists of the renatured inverted duplication sequences as double stranded stem and two single stranded loops of 0.67 m±0.06 m (S-loop) and 0.86 m±0.05 m (L-loop) length. Two additional size classes which comprised 5–10% of the measured molecules had contour lengths of around 1.7 m and 2.1 m. The smaller dumb-bells contained two S-loops and the larger dumb-bells contained two L-loops as was shown by heteroduplex mapping with an HindIII fragment from the L-loop. Two models which assume illegitimate or site specific recombination, are presented to explain the generation of double S-loop and double L-loop molecules. At least part of the 4-m and 6- circular molecules present in the yeast supercoiled DNA fraction are shown to be dimers and trimers of 2-m monomers, but often with inverted loop segments most probably due to intramolecular recombination between sequences of the inverted duplication.2-m DNA is used to indicate the supercoiled DNA fraction although in our measurements the average monomeric length is 1.9 mPart of this work has been presented at the Conference: The Genetics and Biogenesis of Chloroplasts and Mitochondria, Munich, August, 1976     

Intestinal microflora in the deep-sea isopodBathynomus giganteus

Observations with the scanning electron microscope showed that the deep-sea isopodBathynomus giganteus harbors a dense microflora within the digestive tract. The gut microflora is composed of a diversity of microorganisms, including an unusually large bacterial morphotype that predominates almost exclusively in the anterior end of the hindgut. The majority of these large bacteria measured 1.9 m×8.5 m and many reached a size of 2.0 m×10.0 m.     

Triazole treatment of explant source provides stress tolerance in progeny of Geranium (Pelargonium hortorum Bailey) plants regenerated by somatic embryogenesis

Thehypothesis that chemically induced stress tolerance in plants can betransferredto a larger clonal population regenerated by somatic embryogenesis wasevaluatedusing the triazole compound paclobutrazol as a chemical inducer of stresstolerance in Geranium (Pelargonium horturum Bailey). Seedswere imbibed in 3.4, 10.2 or 17.0 M (1, 3, 5 mgL^–1) paclobutrazol for 24 h and germinatedfor 7 days. Hypocotyl explants were cultured in vitro toinduce somatic embryogenesis. Plants regenerated from somatic embryos wereexposed to heat stress at 56°C. Explants treated with3.4 M paclobutrazol yielded a substantially higher number ofsomatic embryos compared with untreated explants. In contrast, 17.0M paclobutrazol treatment inhibited embryogenesis producing asignificantly lower number of somatic embryos. There was no difference in theembryo number between control and 10.2 M treatment. Somaticembryos derived from 3.4 and 10.2 M paclobutrazol treatedexplants developed into plants at a faster rate than the control and 17.0M treatments. Plants derived from paclobutrazol-treatedexplants displayed a greater tolerance to heat stress compared with thecontrols. Observations in this study provide a technique for regeneratingplantsin tissue/cell culture with additional desirable traits such as stresstolerancewith minimal chemical contamination of the environment.     

Transport number effects in the transverse tubular system and their implications for low frequency impedance measurement of capacitance of skeletal muscle fibers

Summary It has been shown in an earlier paper that the slow transient decrease in conductance, somtimes referred to as creep, obtained with small-to-medium hyperpolarizing current or voltage pulses is due to K⁺ transport number differences across the walls of the transverse tubular system. Using the same basic numerical analysis and the parameters already obtained experimentally in the previous paper for frog skeletal muscle in a sulphate Ringer's solution, this paper predicts the equivalent membrane capacitance and dynamic resistance due to transport number effects for very low amplitude and low frequency sinusoidal currents from the phase lag of the voltage response behind the current. Such sinusoidal currentper se give rise to an equivalent capacitance which increased from less than 1F·cm^–2 at 10 Hz to about 16F·cm^–2 at 0.01 Hz and to an equivalent dynamic membrane resistance which increases from its instantaneous slope resistance value of 11.7kcm² at 10 Hz to about 16kcm² at 0.01 Hz. Similar small sinusoidal components of current superimposed on depolarizing and hyperpolarizing pulses (25–45 mV) give rise to even greater capacitances at low frequencies (e.g., 24–28F·cm^–2 at 0.01 Hz). The response due to large sinusoidal currents was also investigated. These transport number effects help to explain the small discrepancies obtained by some workers between experimental and predicted values of skeletal muscle fiber impedances measured in the 1–10 Hz range and would seem to be critical for the interpretation of any skeletal muscle fiber impedance studies done at frequencies less than 1 Hz.     

Lead‐related effects on rat fibroblasts

Lead (Pb) is an environmental toxicant that can induce structural and functional abnormalities of multiple organ systems, including the central nervous and the immune systems. The aim of this study was to evaluate the effects of extracellular Pb supplementation on the cellular content of the metal and on the proliferation and the survival of normal rat fibroblasts.We found that the concentration of Pb in the culture medium was 0.060 M and the normal Pb concentration in rat fibroblasts was 3.1 ± 0.1 ng/10⁷ cells. Then we exposed the cells to increasing concentration of Pb (as Pb acetate) from 0.078–320 M. We observed a dosedependent inhibition of cell proliferation after 48 h, which was already apparent at a concentration of 0.312 M (p = 0.122) and became statistically significant for concentration higher than 0.625 M (p = 0.0003 at 5 M). Cell proliferation was completely compromised at 320 M Pb total inhibition of cell proliferation.To investigate the mechanisms of Pbmediated inhibition of cell proliferation, we evaluated the occurrence of apoptosis in the same cells and found that cytosolic DNA fragments, hallmark of apoptotic cell death, increased significantly at Pb concentrations from 2.5–10.0 M. The occurrence of apoptosis was also confirmed by FACS analysis which showed the appearance of a subdiploid peak at Pb concentrations from 5–20 M. The distribution of cells in the cell cycle showed a dosedependent accumulation of cells in the G₀/G₁ phase mainly compensated by a decrease in the percentage of cells in the S phase. In conclusion, our results demonstrate that induction of apoptosis contributes to the Pbinduced inhibition of cell proliferation in rat fibroblasts.     

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.

     

Ceramide Induces Apoptosis to Immature Cerebellar Granule Cells in Culture

A recent study revealed that ceramide acts as a second messenger in the sphingomyelin pathway and thus plays an important regulatory role in programmed cell death (apoptosis) to cell the lines induced by tumor-necrosis factor (TNF)- and interleukin (IL)-1, although its effect remains controversial regarding primary neuronal culture. We investigated the effect of a cell-permeable ceramide analog (C₂-ceramide) on cultures of cerebellar granule cells, which is thought to have active sphingomyelin pathway during development. The presence of C₂-ceramide decreased the number of cerebellar granule cells (CGCs) in a concentration-dependent manner when added at DIV 1 (1 day in vitro). The ED₅₀ was 60 M. After DIV2, CGCs became less sensitive to C₂-ceramide and the ED₅₀ was 200 M at DIV 7. DNA staining with Hoechst 33258 showed the morphology of apoptotic nuclei in the degenerating neurons. Internucleosomal DNA degradation could also be observed by gel electrophoresis. Protein and RNA synthesis inhibitors prevented the death of neurons. C₂-dihydroceramide, which lacks the 4–5 trans double bond and failed to induce neuronal death. These results thus demonstrated that C₂-ceramide induces apoptosis to the CGCs at the early stage in vitro, however the CGCs were found to be less sensitive to C₂-ceramide at the later stage in vitro.     

Rapid plant regeneration from callus cultures of Plumbago zeylanica

Rapid plant regeneration was achieved in callus cultures derived from leaf and stem explants of Plumbago zeylanica Linn. on MS basal medium supplemented with 4.44 M 6-BA, 1.42 M IAA and 3% (w/v) sucrose. The rate of shoot bud regeneration was positively correlated with the concentration of growth regulators in the nutrient media. The leaf explants were more responsive (82.3%) than the stem explants on medium containing 1.42M IAA in combination with 4.44 M BA. The rate of regeneration was found to maintain the same level for 12 months without loss of vigour. Rooting of the differentiated shoots was achieved in media having 0.57 M IAA with 2% (w/v) sucrose within 10 days of culture. Regenerated plantlets were transferred to soil which grew normally with a survival rate of 90%. This protocol may help in the conservation of the species and selection of variants that may be induced to widen the genetic base of the genus.     

Lack of carcinogenicity of agaritine by subcutaneous administration in mice

Agaritine (A), an ingredient of the cultivated mushroom of commerce Agaricus bisporus, was administered by subcutaneous injection to two groups of randomly bred Swiss mice. In the first group the animals of both sexes were treated at a 100 g/g body weight basis five times at weekly intervals, while in the second group the mice received a single A treatment of 100 g/g body weight for females and 50 g/g body weight for males. The administration of the compound resulted in no detectable carcinogenic effect in the animals. Since some of the breakdown products of A were shown to be carcinogenic in mice and the mushroom itself was found to be mutagenic, the field is discussed in the light of the obtained results.     

Regional and subcellular distribution of taurine-synthesizing enzymes in the rat central nervous system

The distribution of cysteine oxidase (CO) and cysteine sulfinate decarboxylase (CSD) was examined in 12 regions of the rat central nervous system (CNS). The distribution of CO activity, expressed as mol of cysteine sulfinate formed per h per g, was the following: hypothalamus, superior and inferior colliculi, 94–99 mol/h/g; olfactory bulbs, cerebral cortex, striatum, and hippocampus, 44–51 mol/h/g; cerebellum, 71 mol/h/g; pons-medula and spinal cord, 94 and 60 mol/h/g, respectively. The distribution of CSD activity expressed as mol of cysteine sulfinate decarboxylated per h per g was the following: hypothalamus and colliculi, 14–21 mol/h/g; olfactory bulbs, cerebral cortex, striatum, hippocampus, and cerebellum, 8–13 mol/h/g; pons-medulla, 7.3; and spinal cord, 3.6 mol/h/g. No CSD activity was detected in sciatic nerve. The subcellular distribution of CO and CSD activities was studied in hypothalamus, colliculi, and cerebral cortex. CO activity was localized in synaptosomes, mitochondria, and microsomes. CSD was primarily confined to the crude mitochondrial fraction and after subfraction, recovered mainly in the synaptosomal fraction.     

Multiple shoot-bud formation and plantlet regeneration on Castanea sativa Mill. seeds in culture

Primordial initiation and development of shoot-buds has been accomplished by using shoots derived from chestnut (Castanea sativa Mill) seedlings cultured with added 6-benzylaminopurine (BAP). Germination of chestnut seeds in the presence of BAP (4 – 40 M) stimulated varying numbers of shoot-buds in those areas of the main axis that were favorably altered. When excised single shoots from these treated seeds were subcultured on a fresh medium containing BAP (4 – 40 M) continual shoot production was observed. Bud growth and shoot elongation were stimulated by transferring cultures to a reduced concentration of BAP (2 M) plus indole-3-butyric acid (IBA 0.4 M). Plant regeneration occurred in the presence of IBA (0.8 M) after a preconditioning treatment in which naphthaleneacetic acid (NAA 50 M) and kinetin (k 2 M) were applied to the tissue culture shoots for 7 days in light.     

Freßverhalten und Darminhaltsuntersuchungen bei Sipunculiden

Zusammenfassung 1. Die Rolle der Meiofauna als Nahrung für Sipunculiden wurde anPhascolosoma vulgare (de Blainville),Phascolosoma elongatum (Keferstein) undPhyscosoma granulatum (Leukart) geprüft. Die Sipunculiden konnten zur Beobachtung des Verhaltens bei der Nahrungsaufnahme im Laboratorium gehalten werden. Die Nahrung wurde nach Darminhaltsuntersuchungen an konservierten Exemplaren bestimmt.2. Meiofauna wurde in allen Größenklassen der bearbeiteten Arten gefunden. In der Größenklasse I bei 1,0–2,4 cm und in der Größenklasse II bei 2,5–4,9 cm war die Anzahl der aufgenommenen Individuen auf Grund der Sperrigkeit der Crustaceen und der Beweglichkeit der Nematoden gering. Mit zunehmender Größe der Sipunculiden wird das Verhältnis zur Meiofauna als Nahrung günstiger.3. Bei einem Vergleich der im Darm der untersuchten Sipunculiden gefundenen Meiofauna mit derjenigen Meiofauna aus Sedimentproben wird deutlich, daß in Abhängigkeit von der Individuengröße nur Tiere bestimmter Größenklassen als Nahrung aufgenommen werden können.4. Neben der Meiofauna umfaßt das Nahrungsangebot im Substrat auch Protozoen, Pilze und Bakterien sowie partikuläre abgestorbene und gelöste organische Substanzen. Mit der Größenzunahme der Sipunculiden verändert sich die relative Häufigkeit der aufgenommenen Bestandteile aus dem Nahrungsangebot. Eine quantitative Wertung der einzelnen Nahrungskomponenten konnte bisher noch nicht erfolgen.

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Feeding and studies on the gut content in sipunculids

Three sipunculid species were caught in two different biotopes:Phascolosoma vulgare (de Blainville) as well asPhascolosoma elongatum (Keferstein) from a silt-bottom in Gullmarsfjord (Sweden) andPhyscosoma granulatum (Keferstein) from the coralligène near Banyuls-sur-mer (Mediterranean Sea). Observations on feeding behavior showed that the uptake of food is of a passively selective type. Apparently aimlessly, the sipunculids draw in sediment with food from the surroundings, often leaving starlike traces. Examination of gut contents revealed changes in sediment structure in different gut parts. The changes correspond to the different morphological and physiological functions of the gut. The main meiofauna food of the three species, especially nematodes and crustaceans, dominates also in their biotopes. Comparison of the numbers of the meiofauna specimens in the three different parts of the gut showed the expected decrease of food animals. Such decrease applies to all meiofauna-elements; plantdebris seems to pass the intestines unaffected. In order to examine a possible correlation between food and sipunculid size, the latter were classified according to body lenght. Decrease in average nematode lenght is positively correlated to diminishing body size of sipunculids. The same holds for copepods. The food ingested also comprises other organic particles and probably dissolved organic substances.

     

Different effects of inorganic and triethyl lead on growth and ultrastructure of lily pollen tubes

Summary Pollen tubes ofLilium longiflorum growingin vitro were treated for 1 h with inorganic lead (Pb) and with triethyl lead (TriEL) and studied by light and electron microscopy. Pb was considerably more toxic in relation to inhibition of pollen tube growth (EC₅₀=6 M Pb) than was TriEL (EC₅₀=60 M TriEL). On the other hand, at almost the entire concentration range tested (25-500 M) TriEL caused aberrant tubes and tube swellings. Pb did not cause tube swellings, even at highly growth-impairing concentrations. Pb (60 M) predominantly affected the ultrastructure of the growing cell walls without impairing the distribution of the cell organelles in the tube tips. In contrast, 50 and 100 M TriEL did not visibly influence cell wall ultrastructure but it severely damaged dictyosomes; 100 M TriEL also disturbed the original order of cell organelles in the tube tips. Cortical microtubules were selectively and completely destructed by TriEL at concentrations (50 M) where no effect on polar organization of the tube tips occurred but they remained unimpaired by 60 M Pb, indicating selective and effective interaction of TriEL with these cell organelles.Abbreviations EC⁵⁰ effective lead concentration causing 50% inhibition of pollen tube growth - MTs microtubules - Pb inorganic lead - TriAL trialkyl lead - TriEL triethyl lead     

Freeze-fracture studies on the cockroach hemocyte membrane complex: Symmetric and asymmetric membrane particle distributions

Summary Freeze-fracture studies were conducted on the membranes of normal cockroach hemocytes. The plasmalemma is asymmetric with the A fracture face containing 80–100 Å membrane intercalated particles at a concentration of 2500/². The B fracture face contains 120–150 Å particles with a relatively low density (800/²). The nuclear envelope displays an asymmetry with the A fracture face containing 1500 particles/² and the B face containing 300/ ². No significant particle size differences were observed in nuclear envelope fracture faces. Two types of symmetric membranes were also found in these cells. Both A and B fracture faces of the membrane surrounding the numerous cytoplasmic inclusion bodies contain particle sizes and concentrations similar to the B face of the plasmalemma. A second type of symmetry was observed in cells apparently engaged in exocytosis. Vesicles (0.1 D) from this process were completely particle free on both fracture faces. Such particle free vesicles could be found in the cytoplasm, attached to the plasmalemma, or completely separated from the cell.Supported by a Pharmaceutical Manufacturers Association Foundation Fellowship.The author wishes to thank Ms. Annalena K. Charla for assistance in plate preparation, Dr. Julius Schultz and the Papanicolaou Cancer Research Institute for use of the freeze-etch device, and Dr. David Smith for the electron microscope facilities.     

Inhibition of chlorophyll synthesis inHordeum vulgare by 3-amino 2,3-dihydrobenzoic acid (gabaculin)

Gabaculin (3-amino 2,3-dihydrobenzoic acid) is shown to be a very potent inhibitor of chlorophyll formation inHordeum vulgate. Exposure of leaf segments to 30/M gabaculin results in an 80% inhibition of chlorophyll synthesis, and this is paralleled by a decrease in carotenoid. Dual-inhibitor studies with dioxoheptanoic acid, which is an inhibitor of inolaevulinic acid dehydratase, show that gabaculin inhibits an earlier step than dioxoheptanoic acid and affects -aminolaevulinic acid synthesis rather than its subsequent metabolism.     

Effects of external phosphorus supply on internal phosphorus concentration and the initiation,growth and exudation of cluster roots in Hakea prostrata R.Br.

The response of internal phosphorus concentration, cluster-root initiation, and growth and carboxylate exudation to different external P supplies was investigated in Hakea prostrata R.Br. using a split-root design. After removal of most of the taproot, equal amounts of laterals were allowed to grow in two separate pots fastened together at the top, so that the separate root halves could be exposed to different conditions. Plants were grown for 10 weeks in this system; one root half was supplied with 1 M P while the other halves were supplied with 0, 1, 25 or 75 M P. Higher concentrations of P supplied to one root half significantly increased the P concentration of those roots and in the shoots. The P concentrations in root halves supplied with 1 M P were invariably low, regardless of the P concentration supplied to the other root half. Cluster root initiation was completely suppressed on root halves supplied with 25 or 75 M P, whereas it continued on the other halves supplied with 1 M P indicating that cluster-root initiation was regulated by local root P concentration. Cluster-root growth (dry mass increment) on root halves supplied with 1 M P was significantly reduced when the other half was either deprived of P or supplied with 25 or 75 M P. Cluster-root growth was favoured by a low shoot P status at a root P supply that was adequate for increased growth of roots and shoots without increased tissue P concentrations. The differences in cluster-root growth on root halves with the same P supply suggest that decreased cluster-root growth was systemically regulated. Carboxylate-exudation rates from cluster roots on root halves supplied with 1 M P were the same, whether the other root half was supplied with 1, 25 or 75 M P, but were approximately 30 times faster when the other half was deprived of P. Estimates of root P-uptake rates suggest a rather limited capacity for down-regulating P uptake when phosphate was readily available.     

Improved fish lymphocyte culture for chromosome preparation

Cytogenetic methodology is still underdeveloped in fishes compared with mammals. Culture condition for fish lymphocytes was optimized to improve chromosome preparation using the rainbow trout (Oncorhynchus mykiss) as a model after changing the combination of parameters such as mitogens, incubation periods, media, cell components, and freshness of blood. The optimized culture condition included isolation of lymphocytes from fresh blood by a stirring method, their culture in medium 199 supplemented with 10% FBS, 18g/ml of phytohemagglutinin (PHA-W) and 100g/ml of lipopolysaccharide (LPS) as mitogens, and harvested at 6 days after culture. This condition provided a notably increased mitotic index (MI) of 4.3–10.0% in rainbow trout lymphocytes. In addition, the condition was highly reproducible as shown by the similar level of MI in cultured lymphocytes from 181 individuals without failure. Applicability of this method in a wide range of fish groups was also proven with MI of 1.1–13.3% in cultured lymphocytes from other 16 freshwater species of Acipenseridae, Anguillidae, Salmonidae, Cyprinidae, and Centrarchidae, and five marine species of Sparidae, Kyphosidae, Paralichthyidae, and Scorpaenidae. Chromosome preparations of improved quality by the present method were successfully applied for the replication R-banding with incorporation of 5-bromo-2-deoxyuridine and direct R-banding fluorescence in situ hybridization.     

In vitro organogenesis of elephant apple (Feronia limonia)

Elephant apple (Feronia limonia L.). was micropropagated on MS medium containing 4.4 M benzyladenine and 4.6 M kinetin using cotyledon explants taken from in vitro-grown seedlings. Adventitious buds formed on the cotyledon developed into shoots that were rooted in half-strength MS medium containing 0.57 M indoleacetic acid and 0.49 M indolebutyric acid. Plants were successfully established in soil.Abbreviations BA 6-benzyladenine - IAA 3-indoleacetic acid - IBA 3-indolebutyric acid - MS Murashige & Skoog