bluuebunny/crossref_metadata_2025_split huggingface dataset:
PLANT REMAINS FROM THE GRAVENEY BOAT AND THE EARLY HISTORY OFHUMULUS LUPULUSL. IN W. EUROPE
Authors: WILSON D. GAY 
Published: May 2006

SUMMARYOver sixty plant taxa are listed from four samples associated with a boat abandoned at Graveney, Kent, in the tenth century A.D. All samples contained the remains of plants which grow on mudflats and salt marshes, indicating the vegetation immediately around the site. A sample from a brushwood platform beside the boat yielded in addition macro‐fossils of plants that grow beyond the reach of salt water, including shrubs and a number of species that grow in waste places or as weeds of cultivation. Pollen from this sample shows the presence of mixed oak forest somewhere in the region. Parts of the female inflorescence ofHumulus lupulusL. (hop) were also found. They occurred abundantly in the brushwood sample and in one from within the boat, and were also present (though sparsely) in one from just above the floor of the boat. None occurred in the sample from beneath the boat, and no pollen of hop was found in the brushwood sample. It is argued that the boat was carrying a cargo of hops, and the possible implications of this theory are discussed, with reference to the early history of hops and brewing.
ROOT GROWTH AND THE ONSET OF MITOSIS IN GERMINATING VICIA FABA
Authors: ROGAN P. G. , SIMON E. W. 
Published: May 2006

SUMMARYThe length and fresh weight of the root of germinating Vicia seeds increase slowly until 46 h from the start of imbibition and then more rapidly. The dry weight of the root only begins to increase at about 55 h; mitosis starts at the same time.
THE CLIMATIC CONTROL OF THE ALTITUDINAL DISTRIBUTION OF SEDUM ROSE A (L.) SCOP. AND S. TELEPHIUM L.
Authors: WOODWARD F. I. , PIGOTT C. D. 
Published: May 2006

SUMMARYWhen plants of Sedum rosea (L.) Scop, and S. telephium L. ssp. fabaria Syme are grown in competition at different altitudes it is found that the growth of the species is affected differentially. This effect is such that at low altitudes S. telephium is a larger plant than S. rosea, while the reverse is the case at high altitudes. The observed differences are caused by a marked sensitivity of the growth of S. telephium to differences in altitude, while S. rosea is very insensitive.The most probable cause of these responses would appear to be differences of climate. The influence of altitude in northern England on air temperature, saturation deficit and irradiance has been investigated in order to establish the magnitude of the differences which may cause these responses.
LONGITUDINAL AND LATERAL TRANSPORT OF [3, 4‐3H‐] GIBBERELLING A1 AND 3‐INDOLYL (ACETIC ACID‐2‐14C) IN UPRIGHT AND GEO‐TROPICALLY RESPONDING GREEN INTERNODE SEGMENTS FROM HELANTHUS ANNUUS
Authors: PHILLIPS I. D. J. , HARTUNG W. 
Published: May 2006

SUMMARYDistribution of radioactivity from [3H] GA1 and [14C] IAA within the tissues of isolated 2.5 or 3 cm long segments cut from the first internodes of sunflower seedlings was unaffected by displacement from a vertical to horizontal position. This was true whether the agar donor blocks were applied uniformly across the apical cut end of the segments, or where asymmetric donors were used. Neither downward nor upward lateral transport of gibberellin or auxin was influenced. Similarly, use of a lateral donor technique failed to reveal any effect of gravity upon transport across the stem segment to a lateral agar receiver block on the opposite flank. Experiments on etiolated Zea mays coleoptile segments confirmed the existence in this organ of gravity‐induced lateral transport of [14C] IAA.No growth curvatures occurred in upright sunflower stem segments incubated with GA1 or GA3 apical donor blocks applied uniformly or asymmetrically, although elongation growth was enhanced. Horizontally positioned segments exhibited only very weak negative geotropic curvatures when in contact with plain agar blocks, but [3H] GA1 (2 × 10‐6M) donors induced marked curvatures when applied either uniformly or asymmetrically to the apical ends. Asymmetric donor blocks containing IAA induced growth curvatures in both upright and horizontal stem segments.It is concluded that the mechanism of geotropic response in sunflower stems is likely to involve the participation of both auxin and gibberellin, but that these experiments do not suggest that lateral displacement of these hormones is part of such a mechanism. Differences in levels of endogenous gibberellins that are correlated with direction of geotropic curvature may be a consequence of preferential hormone synthesis or transport in the lower or upper sides of horizontally positioned orthogeotropic organs.
THE EFFECT OF ABSCISIC ACID ON GROWTH, PHOTOSYNTHETIC RATE AND CARBOHYDRATE METABOLISM IN LEMNA MINOR L.
Authors: McLAREN JAMES S. , SMITH HARRY 
Published: May 2006

SUMMARYInclusion of 10‐6 M ABA in the growth medium of Lemna minor L. inhibited frond multiplication rate and increased dry weight and relative growth rate per frond. Sugar and starch levels were increased over and above that expected from growth inhibition alone. Transfer of fronds to normal nutrient, after 6 days growth in 10‐6 M ABA, resulted in a higher growth rate than controls and a rapid decrease in accumulated carbohydrates. Net photosynthetic rate was initially increased, but declined after 2 days growth in the presence of ABA. This decrease in photosynthetic rate is discussed in relation to the accumulation of carbohydrates. Respiration rate did not increase with higher carbohydrate levels in the presence of ABA.
WATERLOGGING AND PETIOLE EPINASTY IN TOMATO: THE ROLE OF ETHYLENE AND LOW OXYGEN
Authors: JACKSON MICHAEL B. , CAMPBELL D. JOAN 
Published: May 2006

SUMMARYWaterlogging the soil promotes epinastic growth of tomato petioles and increases the concentration of ethylene which can be extracted from various parts of the shoot. These concentrations exceed those normally required to promote epinasty when applied to the shoots of non‐waterlogged plants.Waterlogging also results in a rapid decline in the concentration of dissolved oxygen in the soil water. Low concentrations of oxygen around the roots of plants growing in nutrient solution promote epinastic growth and also increase ethylene concentration in the leaves. Experiments with detached shoots indicate that the root system is required for the response to low O2concentrations to develop.Ethylene concentrations in the soil can increase during waterlogging to levels which may allow sufficient movement into the shoot to stimulate epinasty.Treatment with substances which can inhibit the action of ethylene, such as carbon dioxide or 7‐chloro‐4‐ethoxycarbonylmethoxy‐5‐methyl‐2, 1,3‐benzothiadiazole also inhibit the epinastic response in waterlogged plants, in plants with low O2 concentrations around the roots and in plants treated with ethylene. The internal level of carbon dioxide in the lower leaves is little affected by waterlogging for up to 96 h.
RE‐MOBILIZATION AND REDISTRIBUTION OF RESERVES IN THE TULIP BULB IN RELATION TO NEW GROWTH UNTIL ANTHESIS
Authors: HO L. C. , REES A. R. 
Published: May 2006

SUMMARYThe organic carbon content and the amount and identity of 14C‐labelled compounds derived from the 14C‐leaf assimilates fixed in the previous season were examined in various organs of tulip bulbs at replanting, on transfer to the glasshouse and at anthesis. Differences in the partition of reserves to various organs were related to the timing of their development and growth, their sink strengths and to their position relative to source organs (initially the bulb scales, later also the leaves). Leaves and roots were the major sinks which received 75% of the 14C‐reserves exported from the scales in the first three months’at low temperature (the first period). After 21 days at 18°C up to anthesis (the second period), the new leaves were a further source of carbon for the continued growth of the flower, stem and daughter bulbs. Daughter bulbs appeared to be the only organs still receiving carbon from the scales during the second period, and this was stored mainly as starch. A high rate of respiratory loss of carbon by the whole tulip plant, and particularly by the scales, was indicated in the second period.
ANALYSES OF AMINO ACIDS IN FLOWER NECTARS OF HYBRIDS AND THEIR PARENTS, WITH PHYLOGENETIC IMPLICATIONS
Authors: BAKER I. , BAKER H. G. 
Published: May 2006

SUMMARYA method for the collection and analysis of free amino acids in very small quantities of nectar is described. By dansylation and three‐system polyamide chromatography individual amino acids may be detected at concentrations as low as 10 pmoles per μl. This has been used for the identification of constellations of acids present in floral nectar from species and hybrids of Aloë, Oxalis, Silene, Cercidium and Armeria. Almost without exception, nectars of F1 hybrids contain all of the amino acids found in the nectars of both parents combined. The usefulness of this‘additiveness’in tracing the phylogeny of groups of species in which allopolyploidy and auto‐polyploidy may have played a role is illustrated by analyses of nectars from species of Geranium (section Ruberta). Also the value of nectar amino acid analyses in the investigation of intro‐gressive hybridization is illustrated by studies of Aquilegia and Penstemon in the Sierra Nevada of California. The constancy of the amino acid patterns in parental species contrasts with the recombination patterns in the hybrid swarms. Finally, it is suggested that nectar amino acid patterns are as useful chemotaxonomically as other groups of plant chemicals and should be utilized accordingly.
THE STABILITY OF CHLOROPLASTS FROM SIPHONACEOUS ALGAE IN SYMBIOSIS WITH SACOGLOSSAN MOLLUSCS
Authors: TRENCH ROBERT K. , OHLHORST SHARON 
Published: May 2006

SUMMARYChloroplasts from siphonaceous algae remain photosynthetically active in the digestive epithelial cells of the sacoglossan opistobranchs Elysia viridis and Tridachia crispata for up to 3 months. During this time, chlorophylls and glycolipids are not synthesized, but the synthesis of small molecular weight metabolites such as sugars, amino acids etc. can readily be demonstrated. Analysis of the capacity of symbiotic chloroplasts to synthesize ribulose diphosphate carboxylase and membrane proteins produced negative results in both instances, even though photosynthetic CO2 fixation could always be demonstrated. These findings show that symbiotic chloroplasts are biochemically stable entities, and that they neither grow nor divide while in the animals’cells. It it likely that chloroplasts depend on the plant cell nucleus and cytoplasmic protein synthesizing machinery for the synthesis of many of their structural and enzymatic components.
STUDIES ON THE NUTRITION AND GROWTH OF DROSERA SPECIES WITH REFERENCE TO THE CARNIVOROUS HABIT
Authors: CHANDLER G. E. , ANDERSON J. W. 
Published: May 2006

SUMMARY Drosera whittakeri was grown in sand cultures supplemented with inorganic salt solutions lacking either nitrogen, sulphur, phosphorus or the microelements. Application of the insect Drosophila melanogaster to the tentacles of plants raised on nitrogen or sulphur deficient medium, enhanced growth, which on nitrogen deficient medium was accompanied by decreased nitrogen content per unit weight although the total nitrogen per plant was unaffected. Application of insects to plants on media deficient in phosphorus or the microelements had no effect on growth but significantly increased the phosphorus content of plants grown on a complete nutrient solution or media deficient in phosphorus or nitrogen. Insects would not serve as a heterotrophic carbon source for the realization of maximum growth of plants grown at very low light intensities.Optimum growth of Drosera binata (and usually D. whittakeri) was attained by applying insects to plants raised on nitrogen‐free medium; addition of inorganic nitrogen (as nitrate) to the nutrient solution to plants raised under these conditions inhibited growth. Optimum growth was not achieved by growing plants on a complete nutrient solution in the absence of insects.Up to 50% of the phosphorus in the tubers of D. whittakeri occurred as inositol hexaphos‐phate. Phosphorus was rapidly transferred to the growing parts of the plant on emergence. During the growing season, plants with higher than average phosphorus content developed new rhizomes on which new tubers formed. The indigenous distribution of Drosera species in southeastern Australia is not restricted to soils of very low phosphorus, nitrogen and sulphur status.
BIOCHEMICAL AND CYTOLOGICAL EFFECTS OF SULPHUR DIOXIDE ON PLANT METABOLISM
Authors: MALHOTRA S. S. , HOCKING D. 
Published: May 2006

SUMMARYBiochemical effects of sulphur dioxide arise from its unique ability to act as an oxidizing or a reducing agent. Among some of the important metabolic effects are direct interference with photosynthetic CO2fixation (competitive inhibition of ribulose diphosphate carboxylase by SO3−) and with energy metabolism (inhibition of mitochondrial ATP production by SO3=). Many indirect effects result from formation of sulphites and organic sulphonates with other cell constituents. These compounds can cause inhibition of a variety of metabolic enzyme systems. All these factors are probably instrumental in the gross disruption of chloroplast and mitochondrial ultrastructure. Injurious effects result when sulphur dioxide is taken up in excess of the capacity of the tissue to incorporate sulphur into the normal metabolic activities.The ubiquitous presence of small amounts of SO, and the subtle and varied nature of its biochemical effects suggest that crop losses to SO, pollution may be more widespread and serious than is generally suspected.
THE MECHANISM OF CHILL‐ AND DROUGHT‐HARDENING OF PHASEOLUS VULGARIS LEAVES
Authors: WILSON J. M. 
Published: May 2006

SUMMARYDrought‐hardening at 25° C, 40% R.H. by witholding water from the roots for 4 days is as effective in preventing chilling‐injury to the leaves of Phaseolus vulgaris as 4 days chill‐hardening at 12° C, 85% R.H. During chill‐hardening the degree of unsaturation of the fatty acids associated with the phospholipids increased and this was considered to prevent water loss and electrolyte leakage by lowering the temperature at which phase changes occur in the membrane lipids to below 5° C (Wilson and Crawford, 1974b). However, drought‐hardening at 25° C, 40% R.H. resulted in no increase in the degree of unsaturation of the phospholipids or glycolipids suggesting that lipid phase changes are not the primary cause of chilling‐injury. Furthermore, a re‐examination of the conditions under which water and electrolytes leak from the leaves of P. vulgaris indicates that phase changes in the membrane lipids of the plasmalemma and other organelles at 5° C are only of minor importance in determining the extent and speed of chilling‐injury. The primary cause of chilling‐injury to P. vulgaris leaves on transfer from 25° C, 85% R.H. to 5° C, 85% R.H. is leaf dehydration due to the opening of the stomata at a time when the permeability of the roots to water is low. The primary factor inducing hardening against chilling‐injury in P. vulgaris is a water stress and not low temperature per se.
AGEING IN EXCISED ROOTS OF TOMATO
Authors: WESTON GEOFFREY D. 
Published: May 2006

SUMMARYIncubation of roots in glucose medium drastically enhanced ageing on subsequent subculture in. sucrose medium. The pretreatment of sector as opposed to tip cultures in 5% glucose reduced the period required to 36 h from the previously lowest figure of 72 h. Excision of root tips caused a reduction in both cell division and enlargement whilst FUDR, hydroxyurea and colchicine reduced the effect of glucose on ageing. The results are discussed in terms of the hypothesis that cell division is required during the glucose treatment for ageing to be enhanced.
ION LOCALIZATION AND SALT SECRETION IN SPOROBOLUS ARENARIUS (GOU.) DUV.‐JOUV.
Authors: RAMATI A. , LIPHSCHITZ NILI , WAISEL Y. 
Published: May 2006

SUMMARYThe secretion of ions from salt glands and the salt content of Sporobolus arenarius leaves were investigated. The NaCl concentration of the test solution was positively correlated with that of the secreted fluid and of the leaves.Electron probe analysis revealed different contents of sodium, potassium and chloride in mesophyll and gland cells. Variations in the relative and absolute content of these ions suggest that an active secretion mechanism is located within the gland cells.
PLANT GROWTH RESPONSES TO VESICULAR‐ARBUSCULAR MYCORRHIZA
Authors: MOSSE B. , POWELL C. LI. , HAYMAN D. S. 
Published: May 2006

SUMMARYInteractions between vesicular‐arbuscular (VA) mycorrhiza, utilization of rock phosphate and nodulation were examined in three legumes (clover, Stylosanthes and Centrosema) and in onions, grown in eight P‐deficient soils ranging from pH 8.1 to 5.3. Irrespective of pH, inoculation with VA endophytes increased P uptake in all host plants in all the soils when the indigenous endophytes had been removed by irradiation, but appreciable increases in plant dry weight only occurred when P concentrations of the uninoculated plants were low, generally below 0.15%. In the acid soils adding rock phosphate generally improved growth of the non‐mycorrhizal plants and inoculation with VA endophytes greatly improved its utilization. The effects persisted when the soil was used a second time. In neutral and alkaline soils rock phosphate was unavailable to non‐mycorrhizal plants and remained so after inoculation with VA endophytes.Legumes inoculated with the appropriate Rhizobium strain only nodulated in the most P‐deficient soils when they were also mycorrhizal, and added rock phosphate greatly improved nodulation and nitrogen fixation of the mycorrhizal plants. Some pilot experiments in unsterile soils are also described and the bearing of these results on field inoculation with VA endophytes is discussed.
‘STALAGMIFORM’ ROOTS IN LIMESTONE CAVES
Authors: LAMONT BYRON B. , LANGE B. J. 
Published: May 2006

SUMMARY‘Stalagmiform’ roots are here defined as dense, stalagmite‐like aggregations of roots and rootlets which protrude from the sandy floor of certain limestone caves. Paper chromatography showed these structures were associated with large trees of Eucalyptus gomphocephala growing above the caves. They seem to form in response to localized abundance of water at sites beneath drip‐points in the cave ceiling.The anatomy of ectomycorrhizal and non‐infected stalagmiform rootlets was similar to that of Eucalypt rootlets. Non‐pathogenic endophytes were also often present, giving many rootlets an endomycorrhizal character. This unusual combination of features places the stalagmiform root in a separate category from other specialized root structures.
SEQUESTRATION OF CYTOPLASMIC ORTHOPHOSPHATE BY MANNOSE AND ITS DIFFERENTIAL EFFECT ON PHOTOSYNTHETIC STARCH SYNTHESIS IN C3 AND C4 SPECIES
Authors: HEROLD A. , LEWIS D. H. , WALKER D. A. 
Published: May 2006

SUMMARYLeaf tissues from many C3 species respond to exogenous mannose in the light by a marked stimulation of starch synthesis. This is attributed to a decreased movement of triose phosphate from the chloroplast following sequestration of cytoplasmic orthophosphate as mannose phosphate and interference with the phosphate translocator. By contrast, in most C4 species, feeding of mannose inhibits starch synthesis. It is concluded that, in these plants, the principal effect of sequestration of orthophosphate is interference with the regeneration of the CO2‐acceptor.
HORMONES IN PLANTS BEARING NITROGEN‐FIXING ROOT NODULES: THE DISTRIBUTION OF CYTOKININS IN VICIA FABA L.
Authors: HENSON I. E. , WHEELER C. T. 
Published: May 2006

SUMMARYCytokinin activity in extracts of nodules, roots, stems and leaves of Vicia faba L. was estimated using the soybean callus bioassay. High levels of cytokinins were present in nodules and leaves while the amounts detected in roots and stems were much lower. Cytokinin levels in the root nodules were as much as twelve to thirteen times those detected in the roots.At least three kinds of cytokinins were present in the plant, two of which had similar chromatographic properties to the cytokinin zeatin and its riboside. The third cytokinin had properties which distinguished it from any of the known cytokinins. This peak was predominant in the leaves while the zeatin riboside‐like peak was the main cytokinin detected in the root nodules and roots.
DAILY PATTERNS OF SHOOT ELONGATION IN PINUS RADIATA AND EUCALYPTUS REGNANS
Authors: CREMER K. W. 
Published: May 2006

SUMMARYDiurnal patterns of shoot elongation, obtained by mechanical growth recorders, were compared with those of leaf elongation and stem radius; the relationships of these to environmental factors were studied in the field and in growth chambers.In sunny weather, minimal elongation (or shrinkage) occurred during the mornings, and maximal elongation rates during late afternoons. On rainy days, elongation patterns tended to be undefined.The observed patterns appeared related to diurnal changes in water balance, air temperature and light. There was no evidence of an endogenous rhythm. Rising evaporative demand during sunny mornings resulted in contractions in shoot and leaf lengths and in the thickness of the stem live bark. Re‐expansion occurred in the evening and at night, or during the day when evaporative demand was reduced by cloud cover and rain. Shoots also contracted on frosty nights, but expanded rapidly following thawing early in the mornings. Temperature also positively influenced growth (i.e. irreversible increase in size). Light appeared to inhibit shoot growth in the mornings, but this effect was confounded with the tendency of shoots to shrink in length due to dehydration.Since growth and reversible changes in shoot length often occurred simultaneously in different portions of the same shoot and since the zones of reversible change and growth overlapped, the measurement and analysis of hourly growth responses can be complicated; a distinction must therefore be made between growth (which is irreversible) and elongation (which may include both growth and reversible changes in shoot length).
SCANNING ELECTRON MICROSCOPIC OBSERVATIONS ON THE GAMETOPHYTE AND SPERM OF THE BRACKEN FERN, PTERIDIUM AQUILINUM (L.) KUHN
Authors: ELMORE H. W. , ADAMS R. J. 
Published: May 2006

SUMMARYThe three‐dimensional structure of the gametophyte and sperm of the bracken fern is described. The sperm consists of a body with approximately three gyres and approximately forty cilia. The cilia are attached to the anterior end and oriented in a latero‐posterior fashion.
THE ORIGINS OF ASPLENIUM CRETICUM AND A. HAUSSKNECHTII
Authors: BROWNSEY P. J. 
Published: May 2006

SUMMARYCytogenetic evidence from experimental hybrids is presented to show that Asplenium haussknechtii, a widespread fern of Asia Minor, is an allotetraploid species which has originated from hybridization between the two diploid species, A. aegaeum and A. ruta‐muraria subsp. dolomiticum. The morphology of the three species is consistent with this hypothesis. Cytogenetic evidence from other experimental hybrids indicates that A. creticum, a fern endemic to Crete, is also allotetraploid, sharing one parent with A. haussknechtii and having A. viride as its second parent. Morphological evidence confirms that A. creticum is most likely to have arisen from hybridization between A. viride and A. aegaeum. Elucidation of the parentage of these two species means that the evolutionary origins of all the tetraploid species of Asplenium known from continental Europe have now been determined. The origins of these species and the development of the Asplenium flora of Crete are discussed in relation to the Pleistocene glaciations.