bluuebunny/crossref_metadata_2025_split huggingface dataset:
POLLINATION IN FICUS RELIGIOSA L. AS CONNECTED WITH THE STRUCTURE AND MODE OF ACTION OF THE POLLEN POCKETS OF BLASTOPHAGA QUADRATICEPS MAYR
Authors: GALIL J. , SNITZER‐PASTERNAK YEHUDIT 
Published: May 2006

Summary Blastophaga quadraticeps, the legitimate pollinator of Ficus religiosa, possesses two thoracic pockets in which pollen is stored for subsequent introduction into the young figs. In nature, pocket‐loading takes place in the nearly ripe fig at the male phase. Impregnated female wasps leave their galls, approach the ripe anthers, and load the pockets by very swift movements of the forelegs. Then they leave the fig via narrow channels bored by the males. Upon entering young receptive figs, the female wasps begin oviposition, during which pocket‐emptying and pollination take place.The pollen pocket of Blastophaga quadraticeps is a complex and highly specialized structure rather than a mere depression or fold of the body wall. Each pocket is a small saccular organ with well‐defined openings. The two marginal exits are very narrow. The third opening is the largest. It gaps widely when the adjacent sternite is touched parallel to the inner border of the pocket and closes shortly afterwards.Loading of the pocket is achieved by two separate actions, which follow each other: The legs transfer the pollen to the thorax and then the pollen is absorbed by some inherent mechanism of the pocket itself, through the wide entrance which opens at the touch of the legs. A technique for artificial loading with various materials (spores, iron particles, etc.) affords good means of studying the inner structure of the pocket.As yet no satisfactory explanation can be offered as to which forces are responsible for the opening of the pocket and the mechanism of pollen absorption.
SITES OF EXUDATION OF14C‐LABELLED COMPOUNDS FROM WHEAT ROOTS
Authors: McDOUGALL BARBARA M. , ROVIRA A. D. 
Published: May 2006

SummaryThe combination of autoradiography and a filter paper ‘sandwich’technique using wheat plants labelled with14C has shown that roots of wheat exude two types of compounds, viz. (a) non‐diffusible material released from the apices of both primary and lateral roots and (b) diffusible material released along the whole length of the roots. The high amount of non‐diffusible material compared with diffusible material suggests that the former may be more significant than previously anticipated in relation to root functions and microorganisms in the rhizosphere.
STUDIES ON THE LIGNOTUBERS OF EUCALYPTUS OBLIQUA L'HERI.
Authors: BLAKE T. J. , CARRODUS B. B. 
Published: May 2006

SummaryA growth inhibiting substance has been extracted from mature tissues of Eucalyptus obliqua in which apical dominance occurs, but is absent in juvenile tissues of very young seedlings which show weak apical dominance. Sprouting from lignotubers in decapitated E. obliqua seedlings is correlated with a reduction in the level of inhibitory properties. Reapplied inhibitory substance, but not abscisic acid, reduced sprouting. The inhibitory substance has been partially purified and some of its properties tested, suggesting that it is not abscisic acid.
FURTHER REMARKS ON THE ‘LEAFLET THEORY’ OF THE OVULE
Authors: GUEDES M. , DUPUY P. 
Published: May 2006

SummaryThe study of teratological flowers of Coriaria ruscifolia L. (Coriariaceae) gives evidence which supports the ‘leaflet theory’ (foliolar theory) of the ovule. The latter appears to be homologous with a leaflet of the carpellary blade, as put forward by certain previous authors and more recently confirmed by the present writers. The fairly complete series of terata here studied support the somewhat theoretical final view of Čelakovský, that the nucellus is fundamentally terminal on the ovular leaflet. The ovule considered has only one integument; its significance may be easily determined. The appearance of an extra nucellus upon an ovular leaflet already provided with the usual nucellus is also described and interpreted.
THE TROPICAL FOREST AND SPORNE'S ADVANCEMENT INDEX
Authors: WOOD D. 
Published: May 2006

SUMMARYSporne found certain characters of dicotyledonous plants were correlated and also well represented in fossil Tertiary floras. He showed that this correlation could be explained by assuming the characters to be primitive and proposed an advancement index based on the proportion of these characters found in each family. By measuring the average advancement index of vegetation from different habitats and of the London Clay Flora, which is the Tertiary flora taken by Sporne as an ancestral standard, it is shown here that there is a clear relationship between the supposed primitive characters and woody habitats. As an alternative to Sporne's hypothesis that the correlated characters are primitive it is suggested that the correlations are a result of the adaptive nature of the characters, the supposedly primitive characters being adaptive to the woody habit, the supposedly advanced characters being adaptive to the herbaceous habit.
METABOLIC CHANGES AND SENESCENCE IN CULTURED PEA ROOT TISSUE
Authors: HABESHAW D. , HEYES J. K. 
Published: May 2006

SummaryThe changes occurring during the maturation, senescence and death of cells in pea roots grown in sterile culture were followed for 30 days after growth by cell extension had ceased. Gross analysis of DNA content and various enzyme activities, analyses of several nitrogen fractions showed that complex changes occurred between the cessation of cell expansion and the death of the root cells. Although the tissue analysed was not homogeneous in cell type, histochemical and anatomical investigations of the distribution and number of nuclei within the root, DNA content of these nuclei and acid phosphatase distribution enabled gross changes to be correlated with changes in the cells of various regions within the root cortex.From the changes observed in the root segment as a whole, two types of process were associated with changes in the cells of the root cortex. The first was a rise in the DNA and protein content of certain areas of the root cortex. It is suggested that this is a consequence of the interaction between the older and younger regions of the root and is not a general characteristic of senescence in cells. The majority of the changes observed were, in general, very similar to those already found in other higher plant systems such as ageing fruits and starving leaves, and were associated with the senescence and death of cortical cells.
QUINONES AND α‐TOCOPHEROL IN GREENING CALLUS CULTURES OF KALANCHOË CRENATA
Authors: THOMAS D. R. , STOBART A. K. 
Published: May 2006

SummaryDark‐grown Kalanchoë callus tissue subcultured into 16‐hour days produce chlorophyll only after several generations. Plastoquinone: chlorophyll molar ratios in extracts from green callus indicate that the level of plastoquinone is somewhat lower than in leaf tissue. This was confirmed in purified chloroplast preparations from callus and leaves. Hill reaction activity was lower in green callus chloroplasts than in those from mature leaves.α‐Tocopherol, although present in non‐green callus, increased with chlorophyll synthesis. D, L[214C]‐mevalonate feeding experiments seem to indicate active sites of α‐tocopherol synthesis other than the mature chloroplast.Changes in ubiquinone and α‐tocopherol content were observed during the growth of dark‐grown callus. Such changes may be due to an increase in mitochondrial populations and to the onset of senescence.
CARPEL PELTATION AND SYNCARPY IN CORIARIA RUSCIFOLIA L.
Authors: Guédès M. 
Published: May 2006

SummaryThe gynoecium of Coriaria ruscifolia is made up of five carpels joined in their lower parts. It is interpreted as syncarpous, not apocarpous, and is considered to represent five peltate carpels free above a very short ventral split and joined narrowly below the split along their median parts, as by so many longitudinal strips. The free part of each carpel consists of the unifacial style (without ventral split) and its short junction with the associate part of the carpel at the level of the ventral split. The joined parts are the ascidiate regions of the carpels with their solid basal union.The study of phyllodic gynoecia enables us to discover the homologies between carpel and leaf in Coriaria and to explain more clearly the peltation concept, which appears to have been misunderstood by English‐speaking botanists.
A SIMPLE METHOD FOR THE DETERMINATION OF CONDUIT LENGTH AND DISTRIBUTION IN STEMS
Authors: MILBURN J. A. , COVEY‐CRUMP P. A. K. 
Published: May 2006

SummaryA simple method for the determination of the lengths and distribution of conduits in plant stems and petioles is described using graphical and algebraic methods. The method proposed by Skene and Balodis (1968) is shown to give improper probability distributions. The data presented by these workers for Eucalyptus‘vessels’ is reinterpreted, giving different results, so far as the accuracy of the data will show. The need for great accuracy in determination of conduit lengths from injection profiles is emphasized.
BIOLOGICAL EFFECTS OF SURFACTANTS
Authors: HEALEY PATRICK L. , ERNST ROBERT , ARDITTI JOSEPH 
Published: May 2006

SummaryEffects of a nonionic surface active agent (lauroyl/myristoyl di (2‐hydroxyethyl) amide) and one anionic surfactant (sodium (linear) dodecylbenzene sulphonate) on cell ultrastructure were determined using Phalaenopsis protocorms. There were no observable effects after 5 days exposure to 1000 ppm of the nonionic. However, the anionic caused severe damage. Drastic changes in morphology, loss of membranes, swelling of thylakoids and appearance of dense osmophilic granules were evident in chloroplasts. Other effects include disintegration of polysomes into monosomes; swelling of mitochondria; dispersion of chromatin in the nucleus; appearance of unidentified vesicles in the cytoplasm and plasmolysis of cells. These ultra‐structural changes can be attributed to the possible emulsification of membrane lipids as well as precipitation and dispersion of cellular proteins.
THE BARNWELL STATION ARCTIC FLORA: A REAPPRAISAL OF SOME PLANT IDENTIFICATIONS
Authors: BELL FRANCES G. , DICKSON CAMILLA A. 
Published: May 2006

SummaryThe plant macrofossils described by Chandler from the classic site of the Barnwell Station beds of Cambridge have been re‐examined. A number of identifications, including all those of strictly Alpine and of extinct species, have been rejected. Some new finds have been added to the list. The changes made do not substantially alter Chandler's ecological interpretation of the flora.
SCANNING ELECTRON MICROSCOPY OF TILIA POLLEN
Authors: CHAMBERS T. C. , GODWIN H. 
Published: May 2006

SummaryA method is described for studying simultaneously the intact and the sectional view of pollen walls. Scanning electron micrographs of such fractured pollen grains of Tilia platypliyllos Scop., T. cordata Mill, and the putative hybrid T.×vulgaris Hayne assist in the interpretation of a number of observations made by light microscopy on the differences between these taxa and confirm and amplify our interpretation of T. platyphyllos made from early transmission electron microscopy of embedded and sectioned grains. The new information makes imperative the distinction between two types of exine reticulation, one bacula‐bordered and the other baculacentric (the Tilia type).
FOSSIL POLLEN OF TILIA FROM THE EAST ANGLIAN FENLAND
Authors: MITTRE VISHNU 
Published: May 2006

SummaryAnalysis of a large number of fossil pollen grains of Tilia from the East Anglian Fenland, led to examination of the characters that might be employed to separate T. platyphyllos from T. cordata. Certain characters were discarded but mesh structure and size in surface reticulation, characters since accepted by other authors, were regarded as satisfactory and made the basis for classifying fossil grains. The results indicated native British status for both species of lime from pollen‐zone Vila onwards, with T. cordata much the commoner, and very high relative frequencies of Tilia pollen in zone Vila and diminution zone by zone thereafter to levels below 0.5% of total tree pollen.
CARBOHYDRATE METABOLISM IN CHAETOMIUM GLOBOSUM
Authors: ADOMAKO D. , KAYE A. G. , LEWIS D. H. 
Published: May 2006

SummarySpecific ATP‐phosphotransferases for glucose, fructose and mannose, and glucosephosphate and mannosephosphate isomerases have been extracted from Chaetomium globosum. The fructokinase is stabilized by potassium whereas the glucokinase is activated by this cation, but is, otherwise, more stable than the former. The less‐studied mannokinase showed no requirement for potassium. The inhibition of the fructokinase by glucose and mannose, and of the glucokinase by mannose are detailed, together with pH optima, Km values and other properties of the enzymes. The level of glucosephosphate isomerase was found to be higher in fructose‐grown than in glucose‐grown mycelium. The role of the enzyme systems in the absorption and utilization of exogenous hexoses is discussed.
THE METABOLISM AND RADIAL MOVEMENT OF GROWTH REGULATORS AND HERBICIDES IN WILLOW STEMS
Authors: FIELD R. J. , PEEL A. J. 
Published: May 2006

SummaryThe metabolism of IAA, NAA, MCPA, 2.4‐D, 2.4.5‐T, MH, TCA and paraquat was investigated in bark strips and stem segments. Both IAA and NAA were extensively metabolized (up to 80% and 40% respectively of the applied compound was converted into other compounds in 24 hours). The principal metabolite of IAA appears to be IAA asp. 2.4‐D, paraquat, TCA and MH were metabolized to a small extent (maximum of 2% in 24 hours), whilst no metabolites were detected from MCPA‐i‐14C and 2.4.5‐T‐I‐14C. The decarboxylation rate of I‐14C‐labelled IAA, NAA and the phenoxyacetic acids was low, IAA having the greatest rate (maximum of 4% of the total activity applied given off as 14CO2 during 48 hours).Investigation of the relative mobilities of the non‐metabolized compounds from xylem to phloem, and from phloem to the xylem stream, revealed that MH, MCPA and 2.4‐D were the most mobile in both directions, TCA and paraquat the least mobile. A comparison of the mobilities of IAA and its metabolites, and NAA and its metabolites, centrifugally and centripetally across the wood was also made. NAA appears more mobile than its metabolites in both directions. In contrast, IAA seems to be more mobile than its metabolites only in a centripetal direction, the converse being found in centrifugal movement.
THE EMPETRUM POLLEN RECORD AS A CLIMATIC INDICATOR IN THE LATE WEICHSELIAN AND EARLY FLANDRIAN OF THE BRITISH ISLES
Authors: BROWN A. P. 
Published: May 2006

SummaryThe climatic patterns, in terms of relative oceanicity and continentality, of the British Isles, for the Late Weichselian and early Flandrian periods, may be derived from palynological records of Empetrum L. Climatic fluctuations in south‐western England in these periods differ dramatically from those of other western areas of the British Isles. A possible reason for the differences is the position of south‐western England in the boundary zone of the activity of the Atlantic and continental European air masses and the consequent increased sensitivity to movements of this boundary zone compared with other regions of the British Isles.
PLANT MICROFOSSILS FROM TERTIARY DEPOSITS OF THE ISLE OF WIGHT
Authors: MACHIN JANE 
Published: May 2006

SummaryPollen and spores have been examined from deposits of presumed Oligocene age occurring in the northern half of the Isle of Wight (southern England). A brief review of the geology and method of investigation is given. The plant microfossils identified are listed and it is shown that they represent a predominantly subtropical swamp vegetation comparable with the more calcareous areas of modern south‐east U.S.A., with an additional strong affinity to the modern swamp and more dry ground flora of subtropical/warm temperate south‐east Asia. In the highest beds investigated an increase in more temperate genera, qualitatively and quantitatively, is found. Comparisons are made with southern English Tertiary macrofossil floras, especially the Bembridge flora. It is shown that some separation within this series of beds can be made on the basis of pollen and spore assemblages and that it is possible to correlate one of these assemblage changes, namely that between the top of the Bembridge Beds and the base of the Hamstead Beds, with a boundary denned on pollen/spore change in the German Tertiary.
A SECTORIAL GREEN‐YELLOW LEAF CHIMERA IN THE POTATO
Authors: HOWARD H. W. 
Published: May 2006

SummaryThe distribution of green and yellow parts in the foliage of a mericlinal chimera suggested that there are six initial cells for layer 2 (L2) in potatoes. The L2 of leaves traces back to only two cells, resulting in some leaves which had green leaflets on one side and yellow on the other; other leaves were all green or all yellow. Layer 3 (L3) showed a behaviour similar to L2 in one year but in the following year a more complex pattern of sectors, leaves having light green as well as normal green and yellow parts, was found suggesting that cell divisions in L3 do not follow so regular a plan as do those in L2.
THE INFLUENCE OF TEMPERATURE ON THE PROCESS OF WATER UPTAKE BY DETACHED LEAVES AND LEAF DISCS
Authors: MILBURN J. A. , WEATHERLEY P. E. 
Published: May 2006

SummaryWhen a water deficit was induced in a mature fully turgid leaf of Ricinus communis L. the tissues could completely regain full turgidity by absorption of water at around 1° C. This was true of large water deficits (40%) which greatly exceeded the cell wall volume (12%). This uptake therefore included movement into the protoplasts and was not restricted to the cell walls alone as had been previously supposed (Weatherley, 1963).However, resaturation of leaf tissues taken from plants which had suffered from drought for more prolonged periods, could be separated into two fractions. An uptake at 1° C was attributable as before to recovery of turgor; an extra uptake at 25° C seemed to be a growth phenomenon inhibited at the lower temperature. This represented a rapid cell expansion following a period of growth arrestment due to water stress.The implications of these findings for the measurement of relative water content are discussed.
α‐N‐MALONYL‐D‐TRYPTOPHAN IN SEEDLING WHEAT ROOTS
Authors: ELLIOTT M. C. 
Published: May 2006

SummaryThe most prominent Ehrlich reactor present in the acid ethyl acetate fraction of extracts of seedling wheat roots is identified as α‐N‐malonyl‐D‐tryptophan. This compound is synthesized by roots fed with 14C‐labelled D‐tryptophan. The compound was without a significant effect on the growth of cultured excised wheat roots over the range 3.45 × 10−12 to 3.45 × 10−6 M.
GROWTH OF ANDROPOGON SCOPARIUS (LITTLE BLUESTEM)IN PHOSPHORUS DEFICIENT SOILS
Authors: WUENSCHER M. L. , GERLOFF G. C. 
Published: May 2006

SummaryThe capacity of a native prairie grass, Andropogon scoparius (little bluestem), to grow successfully in an extremely P deficient soil of central Wisconsin was investigated. This grass is invading ridges, but not depressions, of abandoned fields of Poa pratensis (Kentucky bluegrass). Ridge soils contain less available phosphorus than depression soils. The yield and P absorption of Andropogon and Poa were compared when grown in the low P soil and in nutrient sand culture at various levels of added P. The former consistently outyielded the latter at all levels of P in both soil and sand cultures. Andropogon, which exhibited less yield response to increasing P supply than did Poa when grown in the P deficient ridge soil, was able to absorb much more P from ridge soil. It also utilized absorbed P more efficiently in producing plant dry matter when grown under extreme P stress in sand culture. The critical P concentration for Andropogon was lower than for Poa.
POST‐POLLINATION PHENOMENA IN ORCHID FLOWERS
Authors: ARDITTI JOSEPH , JEFFREY DAVID C. , FLICK BRIGITTA H. 
Published: May 2006

SummaryNAA, in concentrations exceeding 0.01 μg/flower, initiates post‐pollination phenomena in Cymbidium (Orchidaceae) flowers similar to those brought on by pollination. These include stigmatic closure, swelling and loss of curvature of the column, wilting of the perianth, deformation of the calli, and anthocyanin production. Applications of relatively high concentrations of GA3 induce post‐pollination effects which, except for anthocyanin production, are less intense than those brought about by auxin. Kinetin does not induce post‐pollination phenomena, but in concentrations of 10 μg and 100 μg/flower causes slight stigmatic closure, and in some combinations with NAA it inhibits wilting. Stigmatic closure, loss of column curvature and changes in calli, all of them NAA induced, cannot be prevented by simultaneous applications of kinetin, GA3 or ABA. Some combinations of NAA and GA3 lowered anthocyanin content relative to separate treatments with either hormone. Flowers treated with GA3 plus kinetin wilted slightly in most cases, but columns did not swell and retained their curvature; calli did not develop colour and anthocyanin content was generally equal to that of flowers given only kinetin. GA3 and ABA when applied together brought on symtoms which were similar to those caused by ABA only but anthocyanin content was lower than in flowers treated with either hormone alone. This is also true for ABA‐kinetin mixtures, but intensities of the effects are different and, with certain concentration ratios, stigmatic closure occurs. The phenomena are discussed relative to fruit‐set, seed formation, anthocyanin production, senescence, orchid biology and the possible mode of action of each hormone.
CARBOHYDRATE METABOLISM IN THE FUNGUS DENDRYPHIELLA SALINA
Authors: IIOLLIGAN P. M. , JENNINGS D. H. 
Published: May 2006

SummaryStarved cultures of Dendryphiella salina were transferred to defined liquid media containing different carbon sources. Mannitol was accumulated in the mycelium in all except arabitol media. By contrast, the rapidly utilized carbon sources gave high to moderate yields of arabitol whereas, with mannitol or carbon sources that were less readily assimilated, there was little or no increase in the level of pentitol.Variation of the nitrogen source in media containing glucose had a significant effect on the accumulation of arabitol but not of mannitol. The results indicate that the quantity of arabitol synthesized is related to the activity of the pentose‐phosphate pathway which in turn is influenced by the form of nitrogen supplied to the fungus.The activities of certain enzymes were determined and these are discussed in relation to Polyol synthesis.