bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrate Uptake Effectiveness and Utilization Efficiency of Two Plum Clones
Authors: THERIOS IOANNIS N. , WEINBAUM STEVEN A. , CARLSON ROBERT M. 
Published: April 2006

AbstractNitrate uptake and utilization efficiencies of two plum clones, Marianna 2624 (Prunus cerasifera×Prunus munsoniana?) and Myrobalan 3‐J (Prunus cerasifera) in stirred solution cultures were investigated. Myrobalan 3‐J had a significantly lower NO3‐ compensation point (i.e., greater capacity for nitrate depletion) but ceased growth earlier than Marianna 2624 under severe N stress. The maximum velocity of NO3‐ uptake was 33% higher in Marianna 2624 than Myrobalan 3‐J. The nitrogen efficiency ratio (i.e., mg dry weight produced/mg nitrogen absorbed) of Marianna 2624 was 40% higher than Myrobalan 3‐J when nitrogen was severely limiting (28 mg nitrogen per plant). Thus, Marianna 2624 plants may be capable of growth at lower mean nitrogen concentrations.
The Effect of Potassium Deficiency on Stomatal and Cuticular Resistance in Tea (Camellia sinensis)
Authors: NAGARAJAH S. 
Published: April 2006

AbstractThe effect of potassium deficiency on cuticular resistance and diurnal variation in stomatal diffusive resistance was studied in tea (Camellia sinensis). The plants were grown in sand and potassium deficiency induced by withholding the supply of potassium.The results showed that during the day potassium‐deficient leaves had a higher stomatal diffusive resistance than control leaves. However when solar radiation was reduced by clouds the stomatal diffusive resistance in both control and potassium‐deficient leaves was not significantly different. Night opening of stomata was observed in both control and potassium‐deficient leaves, but noticeably lower in the latter. Potassium‐deficient leaves had a lower cuticular resistance than control leaves.
The Effect of Salinity on Growth, Cation Content, Na+‐Uptake and Translocation in Salt‐Sensitive and Salt‐Tolerant Plantago Species
Authors: ERDEI LÁSZLÓ , KUIPER PIETER J. C. 
Published: April 2006

AbstractGrowth of salt‐sensitive Plantago media L. and salt‐tolerant P. coronopus L. and P. maritima L. was followed under saline conditions. Growth was reduced according to the ecological features of these species: P. media was sensitive to 25 mM NaCl, while P, coronopus and P. maritima could grow in 150 mM and 300 mM NaCl, respectively. The three Plantago species accumulated Na+ in the shoot and maintained a relatively low Na+ level in the root. K+. Mg2+ and Ca2+ levels of both shoots and roots decreased with increasing salinity. The results suggest that the difference between salt‐resistant and salt‐sensitive species is located in the ion secretory system which is involved in the ion translocation from the root to the shoot rather than in the primary uptake process through the plasmalemma of the cortical cells.
Germination, Utilization of Storage Materials and Potential for Cyanide Release in Cultivated and Wild Sorghum
Authors: MARBACH IRITH , MAYER A. M. 
Published: April 2006

Abstract Sorghum halepense germinates only after storage and its germination is impeded by its glumes. On germination its metabolism is more rapid than is S. bicolor, as indicated by loss of dry weight, starch and protein and formation of soluble protein and soluble sugars. Fresh weight formation is also more rapid in S. halepense. A method for determining the potential for cyanide liberation is described. S. halepense builds up the potential rapidly and apparently maintains it after germination. This process is also slower in S. bicolor. The results show that the cultivated species is slower in all the processes leading to germination than the wild one.
The Influence of Light and Temperature on Isoprene Emission Rates from Live Oak
Authors: TINGEY DAVID T. , MANNING MARYBETH , GROTHAUS LOUIS C. , BURNS WALTER F. 
Published: April 2006

AbstractThere is a growing awareness of the role of vegetation as a source of reactive hydrocarbons that may serve as photochemical oxidant precursors. A study was designed to assess independently the influence of variable light and temperature on isoprene emissions from live oak (Quercus virginiana Mill.). Plants were conditioned in a growth chamber and then transferred to an environmentally controlled gas‐exchange chamber. Samples of the chamber atmosphere were collected; isoprene was concentrated cryogenically and measured by gas chromatography. A logistic function was used to model isoprene emission rates. Under regimes of low temperature (20°C) or darkness, isoprene emissions were lowest. With increasing temperature or light intensity, the rate of isoprene emission increased, reaching maxima at 800 μE m‐2 s‐1 and 40–44°C, respectively. Higher temperatures caused a large decrease in emissions. Since the emissions of isoprene were light‐saturated at moderate intensities, temperature appeared to be the main factor controlling emissions during most of the day. Carbon lost through isoprene emissions accounted for 0.1 to 2% of the carbon fixed during photosynthesis depending on light intensity and temperature.
Structure of Protochlorophyll‐containing Plastids in the Inner Seed Coat of Pumpkin Seeds (Cucurbita pepo)
Authors: SUNDQVIST CHRISTER , RYBERG HANS 
Published: April 2006

AbstractThe inner seed coat of seeds of Cucurbita pepo L. cv. Ohlsens Enke Köks was used to study the development of protochlorophyll‐containing plastids with an abnormal ultrastructural composition. The pumpkins were harvested at different stages during fruit development and they thus contained seeds with different developmental stages. The dry weight of seeds of the developmental stages used varied from 0.04 g to 0.3 g. Such a series of seeds with decreasing water content indicating increasing maturity contained different amounts of protochlorophyll, from 0.20 μg/g fresh weight to 500 μg/g fresh weight. The ultrastructure of the protochlorophyll containing plastids changed greatly during development. In young seeds with a low content of protochlorophyll, regular prolamellar bodies were found and starch grains filled most of the plastids. During development the starch content decreased and the prolamellar bodies increased in size and lost their regularity. During maturation the plastids accumulated plastoglobuli, probably containing protochlorophyll, and finally the internal structure of the prolamellar body tubular complex was lost.
Cadmium Influence on Respiratory Gas Exchange of Pinus resinosa Pollen
Authors: STRICKLAND RICHARD C. , CHANEY WILLIAM R. 
Published: April 2006

AbstractRelease of CO2 and uptake of O2 by Pinus resinosa Ait. pollen treated with 0, 0.004, 0.045, or 0.450 mM Cd2+ were determined manometrically. Respiration after 1.5 h was stimulated in the 0.450 mM treatment, but declined sharply after 3.5 h. CO2 evolution was inhibited more than O2 uptake. Pretreatment with Cd2+ inhibited aflization of exogenous sucrose, and conversely, exogenous sucrose did not overcome Cd2+ effects on gas exchange. Cd2+ did not act as a classical uncoupler of oxidative phosphorylation. There was no correlation of pollen germination and germ tube elongation with Cd2+ effects on gas exchange.
Phospholipid Involvement in Frost Tolerance
Authors: SIKORSKA ELŻBIETA , KACPERSKA‐PALACZ ALINA 
Published: April 2006

AbstractChanges in frost tolerance and in phospholipid content were studied in the leaves of winter rape plants (Brassica napus L. var. oleifera L. cv. Górczański) grown under natural or artificially controlled conditions. Frost hardening was found to be a three‐stage process. During the first stage, occurring at low but above freezing environmental temperatures, phospholipid changes do not seem to be directly related to the leaf frost tolerance. This stage of hardening is possibly related to a metabolic shift caused by the cessation of growth. The achievement of the second level of frost tolerance in the fully turgid leaves depends on the occurrence of sub‐freezing temperature and is related to increase in phospholipid level. It was shown that freezing brought about phospholipid degradation which was reversible only in slightly injured leaves with a relatively high phospholipid content. The third stage of hardening is related to frost‐induced dehydration of the cells and may overlap the second one.
Oscillations of Leaves of Abutilon theophrasti (Velvetleaf) and their Sensitivity to Bentazon in Relation to Low and High Humidity
Authors: KOUKKARI WILLARD L. , JOHNSON MARGO A. 
Published: April 2006

AbstractThe upper leaf surfaces of velvetleaf (Abutilon theophrasti Medic.) contain trichomes which facilitate the adhesion of droplets of solution, even when the leaves are oriented in a vertical (night) position. Leaves of plants subjected to conditions of high relative humidity were more injured by bentazon (3‐isopropyl‐1H‐2,1,3‐benzothiadiazin‐4(3H)‐one 2,2‐dioxide) than leaves under low soil moisture and relative humidity. Although a significant 24‐h oscillation in the sensitivity of leaves to bentazon was sometimes evident under both high and low humidity conditions, it was definitely more evident in the latter. Generally, the second leaves of plants in the three leaf stage were more consistent for displaying oscillations in sensitivity than the first. The youngest leaves were the most sensitive to bentazon but generally did not display pronounced daily oscillations. The abscission of cotyledons appeared to have possible merit as a bioassay for monitoring leaf injury.
The Influence of Light Quality on Levels of Ahscisic Acid in Tomato Plants, and Evidence for a Novel Abscisic Acid Metabolite
Authors: LOVEYS B. R. 
Published: April 2006

AbstractTomato plants were grown in growth cabinets under two different light sources. One source consisted of white and red fluorescent tubes (Red cabinet), while the second consisted of both tungsten filament and fluorescent lamps (Far red cabinet). Energy fluence rates were adjusted to give equal photosynthetic rates in the two cabinets. Extension growth was approximately three times greater in the Far‐red cabinet. No difference could be detected in abscisic acid (ABA) levels in leaves or petioles of plants grown under the two light regimes, but levels were 40–90% greater in stems of the slower growing plants illuminated with fluorescent light only.Exogenously applied ABA effectively reduced the growth rate of the plants in the Far‐red cabinet to that of plants in the Red cabinet. However, it was shown that light‐induced changes in growth rates occurred before any change in endogenous ABA could be demonstrated, thus precluding a role for ABA in the initial response to a change in light quality.The changed ABA levels appeared to be the result of a modified pathway of ABA degradation. Evidence is presented for a novel metabolite of ABA which yields free ABA on basic hydrolysis.
Cultivar Differences in Starch Content and Protoplast Yields from Root Cortical Ex plants of Pisum salivum
Authors: JEAN CROWDER ANTOINETTE , LANDGREN CRAIG R. , ROCKWOOD LARRY L. 
Published: April 2006

AbstractProtoplasts were isolated from root cortical explants of thirteen cultivars of Pisum sativum. The roots were tested for starch in the cortical tissues. There was a considerable range in the average protoplast yields and the coefficient of variation of those yields from the thirteen cultivars. Cultivars with a higher incidence of starchy roots had lower average explam protoplast yields and greater variation in their protoplast yields. Significantly higher protoplast yields were observed from explants with no starch or few starchy cells. Increasing the germination time of the peas increased the starch content in the seedling roots and decreased the protoplast yields.
Differences in Cuticular Resistance in Relation to Transpiration in Tea (Camellia sinensis)
Authors: NAGARAJAH S. 
Published: April 2006

AbstractExperiments were carried out to investigate whether there were clonal differences in cuticuiar resistance to transpiration in tea (Camellia sinesis) leaves. The cuticular resistance of’ sun and shade leaves was also compared. The drying rate of detached leaves was measured and used as an estimate of cuticular resistance to transpiration. The results showed that there were clonal differences in cuticular resistance in mature and old leaves but not in young leaves. In clonal tea there appeared to be an inverse relationship between she rate of leaf growth and the cuticular resistance in mature leaves. Shade leaves had a higher cuticular resistance than sun leaves.
Fatty Acid Levels in Apple Leaves of Different Age as Affected by Temperature
Authors: KETCHl D. O. , KUIPER P. J. C. 
Published: April 2006

AbstractRelative electrical conductivity (RC) values and Tally acid levels were measured on apple leaves of different ages exposed to 0 and 20°C. RC values were measured at—3°C and high RC values indicate frost‐sensitive tissue. A prolonged period at 0°C gave an increased RC value of the leaves, which indicates damage. At 20°C the RC values were lower in older leaves than in young leaves.The fatty acids level as well as the degree of saturation were different at different ages of the leaves. Young leaves showed a higher fatty acid level in plants held at 20°C than in plants at 0°C. The older leaves maintained the same level after 12 days at 20°C as after 3 days at 20°C. The fatty acid level decreased at 0°C. The linolenic acid level followed the same trend as total fatty acids, indicating that synthesis and degradation of linolenic acid can occur in the same plant depending on the age of the leaf and on the temperature. Cold resistance and linolenic acid levels were correlated in both old and young leaves at 20°C and in older leaves at 0°C. There was no correlation between cold resistance and levels of linotenic acid levels in young leaves at 0°C. Two hiosynthetic pathways for linolenic acid synthesis are discussed.
Diurnal and Seasonal Changes in Leaf Water Potential Components and Elastic Properties in Response to Water Stress in Apple Trees
Authors: DAVIES FREDERICK S. , LAKSO ALAN N. 
Published: April 2006

AbstractApple trees are very drought tolerant, having the capability to grow and carry on photosynthesis even at low water potentials. Much of the tolerance is due to the ability of apple leaves to maintain turgor potentials at levels conducive to growth and stomatal opening. Diurnally, leaf turgor is maintained through decreases in osmotic potentials (due to active solute accumulation), osmotic adjustment, or to concentration of solutes via tissue water loss. These two processes combined may decrease osmotic potentials by as much as 1.65 MPn during the day. Seasonally, osmotic potentials remain fairly constant, but leaf elasticity increases, allowing growth to continue and stomata to remain open us water and turgor potentials become progressively lower. Release of stored water from plant tissues to the transpiration stream is another means of preventing water potentials from reaching critical values for stomatal closure. A combination of a number of these physiological adaptations may account for much of the drought tolerance in apple trees.
Carotenoid and Steroid Syntheses by Carrot Cells in Suspension Culture
Authors: SHIMIZU KAYOKO , KIKUCHI TOHRU , SUGANO NOBUHIKO , NISHI ARASUKE 
Published: April 2006

AbstractBiosynthesis of carotenoids and steroids in tissue cultures of carrot cells I Daucus carota L.) was studied by measuring the change in their contents and incorporation of 14lC‐acelate. The rate of synthesis of these plant products varied significantly during the growth cycle in batch culture. Carotenoids were most actively synthesized in the early logarithmic phase and the synthetic rate sharply declined as the culture aged, whereas the rate of accumulation of phytosterols was highest at the end of the growth phase. Newly synthesized carotenes were shown to undergo turnover during the growth. The synthesis of both carotecnoid and steroid was stimulated by 2.‐ 4‐dichlorophenoxyacetic acid.
Quantitative and Qualitative Changes in Peroxidase during Germination of Mung Bean under Salt Stress
Authors: SHEORAN I. S. , GARG O. P. 
Published: April 2006

AbstractSeeds of mung bean (Phaseolus aureus Roxb.) cv. Pusa Baisakhi were surface sterilized with sodium hypochlorite solution and sown both in Petri dishes and in sand culture containing aqueous solutions of four different salts, viz. NaCI, KCI, Na2SO4 and K2SO4, each at 5 and 10 S/cm. Peroxidase activity and its isoenzymes were studied in different plant parts at suitable time intervals during germination. Activity of peroxidase increased in embryo axis and leaves but decreased in cotyledons and roots with different salt treatments to varying degrees. A highly significant inverse correlation (r= ‐0.931 was found between the peroxidase level and the growth of embryo axis under saline conditions. The number of isoenzymes of peroxidase increased with increase in the time of germination. Salinity treatments resulted in the appearance of new isoenzymes in all the plant organs except roots where the isoenzymic pattern remained unchanged. Different types of salinity resulted in the appearance or/and disappearance of different isoenzymes.
Stomatal Responses of Fraxinus pennsylvanica Seedlings during and after Flooding
Authors: KOZLOWSKI T. T. , PALLARDY S. G. 
Published: April 2006

AbstractEffects of flooding for 10, 20, 30, or 40 days on leaf diffusion resistance (r1) of fraxinus pennsylvanica seedlings were studied during the period of flooding and continuing for 17 days after flooding. All Flooding treatments induced stomatal closure, as indicated by increased r1. There was some evidence of stomatal adaptation to flooding, with stomata beginning to reopen after a critical period of flooding. After termination of flooding, stomata opened further within 6 to 10 days to near preflooding levels. The degree of stomatal opening was only slightly higher after 10 days than after 40 days of flooding. Some stomata may have been permanently damaged by flooding. The stomatal adaptation to flooding as well as rapid recovery of stomatal opening, even after prolonged flooding, appeared to be important factors in the flooding tolerance of Fraxinus petmsylvanica and are consistent with its distribution on wet sites.
The Effect of 2,3.5 Triiodobenzoic Acid on Caulogenesis in Callus Cultures of Tomato and Pelargonium
Authors: CASSELLS ALAN C. 
Published: April 2006

AbstractStem explants from winter grown tomatoes cultured on a cytokinin, auxin‐free medium, developed one or two adventitious shoots at the top end of the explant. Addition of the auxin transport inhibitor. 2,3,5‐triiodobenzoic acid (TIBA) to the medium stimulated caulogenesis with loss of polarity.Callus, initiation in pelargonium and ‘geranium’ petiole explants requires both auxin and cytokinin. On transfer, after callus induction to an auxin‐free medium, rhizogenesis occurs in pelargonium cultures followed by caulogenesis. Few shoots develop and unless these are removed, further caulogenesis is suppressed. Bud‐like structures were formed in the callus. Subculture on auxin‐free medium containing cytokinin and TIBA resulted in shoot formation from these bud‐like organs. An analogy with apical dominance is suggested. In ‘geranium’ callus, shoots developed with a low frequency (c. in 2% of the cultures): caulogenesis was increased to 80% when calli were subcultured from auxin‐free, cytokinin medium after green nodule formation to cytokinin‐TIBA medium.Histological studies of green nodules in ‘geranium’ callus indicated a variation in morphological development within and between nodules. It is suggested that auxin synthesis may occur at some microscopic stage in morphogenesis in ‘geranium’ cultures which suppresses further caulogenesis. This may be overcome by the addition of TIBA to the medium at the appropriate stage in morphogenesis.The possible interaction of endogenous auxin in morphogenesis is discussed.
Light and Temperature Requirements during Fruit‐Body Development of a Basidiomycete Mushroom, Coprinus congregates
Authors: ROBERT J. C. , DURAND R. 
Published: April 2006

AbstractLight initiated fruit body primordia of Coprinus congregatus Bull, ex Fr. grown at relatively high temperature (25°C) require a single dark period or low‐temperature induction for completion of fruit‐body development. The dark period requirement varied with the temperature regime during the inductive dark period A minimum requirement of 2.5 h was found al 15–20°C. Darkness always promotes development of fruit‐body primordial, but cannot, be regarded as an absolute necessity until temperature exceeds about 17.5°C. Normal development of me primordia without darkness was obtained by lowering the temperature to 10°C for 6 h. It appeared that at high temperatures two successive stimuli were required for basidiocarp maturation, a light‐off and a subsequent signal light‐on signal. On the contrary, at 10°C a single low‐temperature signal seemed to be involved. Thus, induction of fruit‐body development could be produced by alternative pathways. These developmental features have been extended to other fungi and compared with the flowering processes of some short‐day plants.
Differentiation in Lilium Bulbscales Grown in vitro. Effect of Various Cultural Conditions
Authors: TAKAYAMA SHINSAKU , MISAWA MASANARU 
Published: April 2006

AbstractTissue cultures of Lilium auratum Lindl. and L. speciosum Thunb., which were derived from bulbscales, all appeared to differentiate organs. The effect of cultural conditions on the differentiation of bulblets and roots was examined.The best material for bulblet formation was bulbscales of intact or in vitro produced bulblets. The optimum temperature was 20°C and optimum pH was 6. Effect of irradiance on organ formation was not obvious but leaf emergence was stimulated.Higher kinetin concentrations stimulate the formation of numerous bulbscalcs. High NAA concentrations induce roots. On the other hand kinetin inhibits the NAA effect on root formation. A high sucrose concentration stimulated organ formation, but the number of bulblets was at a constant level in the medium containing between 10 and 90 g/l of sucrose. The formation of bulblets and their growth were stimulated at increasing strength of Murashige‐Skoog's (MS) medium, but the length of roots was inhibited. Inter action of strength of MS medium and sucrose concentration was examined. High concentration of both components stimulated bulb lei growth, but the second strength of MS medium containing 90 or 120 g/l sucrose stimulated callus induction and inhibited the growth of bulblets.Maximum growth took 100 days for bulblets and about 50 days for roots. The change of fresh weight/dry weight ratio during differentiation is also discussed.
Effect of Far Red and Red Light on a Pelletable Peroxidase Activity in Extracts from Spinach Leaves
Authors: PENEL CLAUDE , GREPPIN HUBERT 
Published: April 2006

AbstractThe effect of in vitro irradiations on ihe pelletability of peroxitlase activity was tested in extracts prepared from leaves of light‐grown spinach (Spinacia oleracea). It appeared that far red light increased the pelletable activity and that red light reversed this effect. This phytochrome‐mediated effect occurred in a particulate fraction which banded at 39% (w/w) sucrose on an isopycnic density gradient.