bluuebunny/crossref_metadata_2025 huggingface dataset:
ELECTRON MICROSCOPY OF ISOLATED PLANT MITOCHONDRIA AND PLASTIDS USING BOTH THE THIN-SECTION AND NEGATIVE-STAINING TECHNIQUES
Authors: Parsons D. F. , Bonner Jr. W. D. , Verboon J. G.
Published: August 2008

Six types of plant mitochondria have been isolated by improved techniques and examined with the electron microscope by the thin-section and negative-staining techniques. In general, the mitochondria appeared well preserved. There was minimal contamination by endoplasmic reticulum but some plastids were present. The morphology of the plant mitochondria is compared with that of animal cell mitochondria. Negative staining showed that the inner membranes were covered with projecting knob-like subunits, as previously described for animal and insect cell mitochondria. The outer membrane showed a characteristic pitted appearance that was apparently due to 28 Å holes in the membrane. A preliminary report is also given of the appearance of negatively stained membranes of chloroplasts.
CHROMOSOME NUMBERS OF THE FAMILY CRUCIFERAE. II
Authors: Mulligan Gerald A.
Published: August 2008

Chromosome numbers and taxonomic discussions are given for North American material of species in the genera Braya and Cardamine. The following chromosome numbers are reported for the first time: Braya humilis s.l., n = 14 and 2n = 28; Cardamine angulata, n = 20, and 2n = 40; C. cordifolia, 2n = 24; C. microphylla, 2n = 32; C. occidentalis, n = 32 and 2n = 64; C. oligosperma, 2n = 16; C. pensylvanica, 2n = 64; C. umbellata, n = 24 and 2n = 48. It is concluded that the base number of Braya is x = 7 not x = 8 and that North American species of Cardamine have the base numbers x = 6, 8, and 10.
INFLUENCE OF NUTRIENTS ON PERITHECIAL PRODUCTION OF VENTURIA INAEQUALIS (CKE.) WINT.
Authors: Ross R. G. , Hamlin S. A.
Published: August 2008

Nitrates, urea, and amino acids were suitable sources of nitrogen, within a narrow range of concentrations, for perithecial development of Venturia inaequalis in a synthetic medium. Ammonium sulfate was not. The concentration of amino acid nitrogen required to inhibit the formation of perithecia varied with the amino acid. Zinc appeared to stimulate perithecial production. Amino acids differed in the nitrogen concentrations required to inhibit formation of perithecia. Perithecia developed in low concentrations of arabinose, glucose, sucrose, lactose, and maltose but did not develop in xylose, ribose, fructose, mannose, or galactose. The disaccharides were particularly suitable. Thiamine appeared to be necessary for ascospore formation.
THE GROWTH PATTERN OF CORN IN RELATION TO RESISTANCE TO ROOT AND STALK ROT
Authors: Wall R. E. , Mortimore C. G.
Published: August 2008

Single-cross hybrids resistant to root and stalk rot generally had greater growth rates, leaf areas, and stalk densities than susceptible single crosses. Differences in dry weight of tops were evident by the time of silk emergence and these differences became more pronounced as the hybrids approached maturity. Susceptible hybrids were characterized by a cessation of vegetative growth at pollination and a rapid senescence of leaves at or shortly after physiological maturity. Hybrids resistant to root and stalk rot were characterized by a continued increase in vegetative dry matter for several weeks after pollination, resulting in relatively heavy lower stalks and a high ratio of vegetative tissue to grain. The density of pith tissue from the lower stalk at physiological maturity was negatively correlated with subsequent stalk rot incidence.
FINE STRUCTURE OF THE AGARICUS CARPOPHORE
Authors: Manocha M. S.
Published: August 2008

The fine structure in the carpophore of the mushroom, Agaricus campestris, was studied with the electron microscope. The stipe consists of two types of cells (i) fundamental and (ii) long and thread-like. The pileus contains only the first type. The tramal cells of the gills are more elongated than broad, regularly arranged, and rich in cytoplasmic contents. The cross wall of the hyphal cells shows a conspicuous pore apparatus with dark septal swellings encased in the plasma membrane. The nuclear membranes are differentiated early during nuclear division and are highly alveolated around the interphase nucleus. In the maturing basidium, the mitochondria increase in number by division of pre-existing ones, and thus become small with few cristae. Numerous vacuoles appear in the upper portion of the basidium. Oil globules are also produced in the mature basidium but were not observed during the early stages of development of the basidium or in any other part of the carpophore. The young basidium has food reserve which is granular in nature. The basidiospore contains numerous large oil globules, few mitochondria, scanty endoplasmic reticulum, and a wall of three well-defined layers.
STEROL PRODUCTION BY SOME WOOD-ROTTING BASIDIOMYCETES
Authors: Milazzo Francis H.
Published: August 2008

Fourteen species (six genera) of wood-rotting basidiomycetes cultured in a chemically defined medium were examined for the presence of sterol material. These fungi were found to contain ergosterol in amounts that ranged in value from 0.017 to 0.42% of their mycelial dry weights. Such values are, in general, comparable to sterol values reported for other fungi.The synthesis of sterol by Fomes meliae was found to accompany active growth of the fungus and was quantitatively influenced by the composition of the growth medium. Hexose supported greater production of sterol than did pentose, and organic nitrogen was superior to inorganic nitrogen in respect to this synthesis. The combination of hexose and organic nitrogen supported the greatest synthesis of sterol.
THE EPIDEMIOLOGY OF THE JACK PINE – OAK GALL RUST (CRONARTIUM QUERCUUM) IN WISCONSIN
Authors: Nighswander James E. , Patton Robert F.
Published: August 2008

In studies of Cronartium quercuum (Berk.) Miyabe ex Shirai, temperature and moisture conditions necessary for spore production, spore germination, and oak and pine infection were determined. Seasonal development studies then revealed that a series of favorable events was necessary for an inoculum "buildup" to occur on oak. Initial infection of oak by aeciospores resulted from at least 10 hours of saturated air accompanied by free water with the temperature between 8° and 28 °C. Late spring frosts and dry weather during aeciospore dissemination limited the spread. Secondary spread by urediospores was limited by dry weather and the decreasing susceptibility of oak leaves with age. The susceptible foliage produced by sprouts from recently cut oak stumps tended to prolong uredial spread. Infection of pine was only possible when viable teliospores were present on oak. During the years 1955–1958 in central Wisconsin they were present from the first week in June until the first of July if secondary spread by urediospores did not occur, or for about 2 weeks longer if secondary spread did take place. A period of at least 13 hours of 100% relative humidity following a measurable rainfall was necessary for production and germination of basidiospores. These conditions occurred infrequently and in some years not at all in central Wisconsin.
A FURTHER STUDY OF CALLUS TISSUE DEVELOPMENT ON STEM CUTTINGS OF BALSAM POPLAR
Authors: Cormack R. G. H. , Lemay P. L.
Published: August 2008

When balsam poplar stem cuttings are grown in a saturated solution of CaSO4 (pH 11.0) for 10 days and then transferred to distilled water for another 10 days a resulting callus mass shows two distinct kinds of callus tissue. When the procedure is reversed, the position of the two kinds of callus tissue in a single callus mass is correspondingly reversed. The relationship of each kind of callus tissue to fungal infection and to the development of adventitious roots is briefly discussed.
ELECTRON MICROSCOPIC STUDY OF THE PROTOPLASMIC CONTINUITY IN CERTAIN BROWN ALGAE
Authors: Bisalputra T.
Published: August 2008

The protoplasmic continuity in the meristoderm and outer cortex of the blades of Egregia menziesii and Fucus evanescens is demonstrated by electron micros copy. Groups of small pores of the order of 37.5 mμ in diameter perforate the walls in these regions. Traversing the pores are protoplasmic strands connecting the adjacent protoplasts. It is concluded that these pores are plasmodesmata which occur in primary pit fields. Endoplasmic reticulum is not found within the plasmodesma.
A NEW LOCULOASCOMYCETE ON ABIES BALSAMEA (L.) MILL.
Authors: Reid James , Pirozynski K. A.
Published: August 2008

Pseudoscypha abietis J. Reid & Pirozynski gen. nov., sp. nov. associated with a needle blight of Abies balsamea (L.) Mill. is described as a new member of the Loculoascomycetes.
CONTROL OF CELLULASE ACTIVITY BY INDOLEACETIC ACID
Authors: Fan Der-Fong , Maclachlan G. A.
Published: August 2008

Apices of etiolated decapitated Alaska pea seedlings were painted with aqueous lanolin + IAA ± various inhibitors of RNA or protein synthesis. A subapical segment from the epicotyl was removed for measurements of growth and the soluble protein content and cellulase activity of enzyme extracts.During the first 18 hours, the main growth response to IAA was an increase in segment diameter; elongation was inhibited. The amount of extractable cellulase activity per segment and the diameter increased at exactly the same rates relative to controls. In the next 2 days IAA induced rapid cell division and the formation of root primordia. Cellulase activity per segment, per unit fresh weight, and per unit soluble protein all increased markedly to levels many times higher than in controls. Chloramphenicol, azaguanine, puromycin, and actinomycin D all interfered with protein synthesis, the growth responses, and the development of cellulase activity. In the absence of IAA, cellulase activity decreased.It is concluded that cellulase is subject to turnover in this tissue and that the rate of its synthesis is controlled by auxin concentration. It is proposed that cellulase action on microfibrils in vivo plays an essential role in a variety of growth processes, particularly lateral cell expansion.
INFLUENCE OF TEMPERATURE ON THE VIABILITY, VIRULENCE, AND PHYSIOLOGIC CHARACTERISTICS OF XANTHOMONAS PHASEOLI VAR. FUSCANS IN VIVO AND IN VITRO
Authors: Basu P. K. , Wallen V. R.
Published: August 2008

Xanthomonas phaseoli var. fuscans (Burkh.) Starr & Burkh. in naturally infected bean seeds stored at −20 to 35 °C retained its viability, virulence, and physiological properties for 3 years. Agar cultures of the pathogen maintained at −20 to 20 °C also retained their pathogenicity and physiological characters throughout the test period but showed less virulence than the seed-borne isolates by the end of 33 months. The viability of agar cultures held at 25, 30, and 35 °C was lost after 24, 18, and 9 months of storage, respectively.The effects of 24 carbon sources on the growth of the pathogen have been determined. The production of a brown diffusible pigment by the organism was influenced by temperature, aeration, and the carbon source. Sugar alcohols did not support good growth or inhibit pigment formation. Most carbohydrates, which supported good or fair growth of the organism, seemed to inhibit pigment production or its expression.
SELFING STUDIES WITH RACES 10 AND 11 OF WHEAT STEM RUST
Authors: Green G. J.
Published: August 2008

In selfing studies with four cultures of race 11 and one of race 10 of wheat stem rust (Puccinia graminis Pers. f. sp. tritici Erikss. and Henn.) segregation ratios indicated that a single dominant gene governs virulence on the varieties Arnautka and Mindum and single recessive genes govern virulence on the varieties Marquis-Sr8, Marquis-Sr9a, and Marquis-Sr11. Virulence on Marquis-Sr9b appeared to be recessive but the observed ratio was a poor fit to a single factor ratio.
EFFECT OF DAYLENGTH ON THE GROWTH OF WHEAT
Authors: Friend D. J. C. , Helson V. A. , Fisher J. E.
Published: August 2008

Leaf area per plant, total number of leaves and tillers, and total plant dry weight increased with increasing daylength over the range 8 to 24 h. The increase in the net assimilation rate and relative growth rate with increasing daily total radiation was similar to that obtained by raising the intensity of light given to plants grown under continuous illumination.During the vegetative phase of growth, the leaf area ratio decreased with increasing daylength, mostly because of an increased leaf thickness, again dependent on the level of total daily radiation. During the later stages of growth, earlier floral initiation at long daylengths caused an early decline in the leaf area ratio because of the rapid growth of the stem associated with inflorescence formation. This was a photoperiodic effect independent of the level of total daily radiation, as shown by supplementing an 8-h daylength with 8 h of low-intensity illumination.
INVESTIGATIONS OF THE MARINE ALGAE OF NOVA SCOTIA: II. SPECIES OF RHODOPHYCEAE NEW OR RARE TO NOVA SCOTIA
Authors: Edelstein T. , McLachlan J. , Craigie J. S.
Published: August 2008

Thirty-four species of Rhodophyceae are described and 25 of these are new records for Nova Scotia. A large number of these species were collected either in the sublittoral area, to a depth of 38 m, or in warm-water, salt-marsh habitats.
INVESTIGATIONS OF THE MARINE ALGAE OF NOVA SCOTIA: III. SPECIES OF PHAEOPHYCEAE NEW OR RARE TO NOVA SCOTIA
Authors: Edelstein T. , McLachlan J.
Published: August 2008

Twenty-nine species of Phaeophyceae are described, and 25 of these are new records for Nova Scotia. Six species are new to North America: Feldmania irregularis (Kützing) Hamel, Mikrosyphar polysiphonia Kuckuck, Phloeospora curta (Foslie) Jaasund, Sphacelaria saxatilis (Kuckuck) Sauvageau, Streblonema immersum Levring?, and S. tenuissimum Hauck?.
PRINCIPAL COMPONENTS ANALYSIS OF DATA FROM SAXICOLOUS BRYOPHYTE VEGETATION AT STEPS BRIDGE, DEVON: II. AN EXPERIMENT WITH HETEROGENEITY
Authors: Yarranton G. A.
Published: August 2008

It has been suggested that the presence of heterogeneity in data may obstruct the extraction of components in principal components analysis and this is tested as follows.Heterogeneity in species-contact data collected from saxicolous bryophyte vegetation at Steps Bridge is described. The division of each of two forms of the data into two clusters is demonstrated and the results of principal components analyses of the four clusters are presented. The informativeness of a principal components analysis of the whole data is compared with that of the analyses of its constituent clusters and is shown to be the same. It is concluded that heterogeneity of the level encountered here does not reduce the effectiveness of principal components analysis.
TORULA TERRESTRIS N. SP. FROM SOIL
Authors: Misra P. C.
Published: August 2008

Torula terrestris Misra, a new species isolated from Shorea robusta forest soil of Gorakhpur, India, is described and illustrated.
THE INCIDENCE OF CROWN ROT OF BOXED BANANAS IN RELATION TO MICROBIAL POPULATIONS OF THE CROWN TISSUE
Authors: Lukezic F. L. , Kaiser W. J. , Martinez Maria M.
Published: August 2008

During a period of 10 months, weekly samples were taken of rotted banana crowns to determine the microorganisms associated with rot. On a total of 648 crowns, Cephalosporium sp. occurred on 93%, Verticillium theobromae 81%, Fusarium roseum 'Gibbosum' 80%, F. moniliforme 14%, Botryodiplodia theobromae 12%, and Gloeosporium musarum 3%. Isolates of these organisms from green crowns, bracts, flowers, and petioles of the banana plant were able to rot crown segments in laboratory tests. Cephalosporium sp. has been shown for the first time to be capable of causing crown rot. Cultures of F. roseum from the air, grass, and Drosophila sp. were also pathogenic. A synergistic effect on rotting was demonstrated between F. roseum and bacteria isolated from crown tissue. Crown rot incidence fluctuated during the sample period, but this could not be correlated with changes in the occurrence of causal organisms present on the crowns.
BASIC CHROMOSOME NUMBER, CYANOGENETIC GLUCOSIDE VARIATION, AND GEOGRAPHIC DISTRIBUTION OF LOTUS SPECIES
Authors: Grant William F. , Sidhu B. S.
Published: August 2008

Leaves of 51 species and three varieties of Lotus (Leguminosae) were assessed quantitatively for hydrocyanic acid (HCN) reaction intensity and the data correlated with basic chromosome number and geographic distribution. The presence of HCN was determined from 0.05 grams of fresh leaf samples by the picric acid – filter paper technique. A gradation of 10 different color reactions (−), (±), and (+1 to +8) was used to compare the HCN reaction for each species. On the basis of potassium cyanide equivalents, each gram of fresh leaf material was estimated to contain an amount of HCN which varied between the different plants and accessions from 0.5 mg to 750 mg. Most of the Old World species were positive for HCN, whereas the reverse was true for the North American species. This would favor the previous separation of the North American species into a separate genus Hosackia. All of the n = 7 species have a greater concentration of HCN than the n = 6 species in both the Old and New World. None of the n = 6 species in the New World reacted positively. Therefore, there was a reduction of HCN with evolutionary development. Two colchicine-induced tetraploids (4x = 24, 28) gave a lower HCN reaction than their diploid counterparts. Leaves of L. siliquosus (n = 7) reacted negatively to the HCN test; however, the cotyledons gave a highly positive reaction supporting the retention of the generic name Tetragonolobus (T. siliquosus (L.) Roth.) for this species. Chromosome number determinations are reported for the first time for L. holosericeus Webb and Berth. (2n = 14), L. mascaensis Buchard (2n = 28), L. nevadensis Greene (2n = 14), L. helleri Britton (2n = 14), and L. oblongifolius var. nevadensis (Gray) Munz (2n = 14).
FREQUENCY OF LAMMAS GROWTH IN A PROVENANCE TEST OF RED PINE
Authors: Lester D. T. , Rehfeldt G. E.
Published: August 2008

Variation in the frequency of lammas growth among 18 Canadian seed sources and Wisconsin control stock at ages 11 and 13 was studied in a central Wisconsin plantation. Analyses of variance indicated a predominant effect of year of observation on frequency of lammas growth. Seed source effects were highly significant statistically, but contributed relatively little to total variance.
HISTOCHEMICAL CHANGES IN THE SHOOT TIP OF CAULIFLOWER DURING FLORAL INDUCTION
Authors: Sadik Sidki , Ozbun J. L.
Published: August 2008

Cauliflower plants were induced to flower after being grown at 42 °F for varying periods of time, depending on the cultivar. Some of the histochemical changes in the shoot apex at the beginning of, during, and after floral induction were studied. During floral induction there is about a 20-fold increase in the volume of nucleoli and about a 3-fold increase in volume of nuclei. Apices of vegetative plants stained with bromophenol blue at pH 2.3, show small and dense nucleoli, dense and granular nuclei, and a small amount of weakly staining cytoplasm. In contrast, cells of apices of induced plants stained with bromophenol blue at pH 2.3, show large and dense nucleoli, large and weakly staining nuclei; however, these cells contain more and denser cytoplasm. Sections of vegetative and induced apices stained with alkaline fast green stained differently from those stained with bromophenol blue. Nucleoli did not stain and cytoplasm stained faintly with fast green while chromosomes stained strongly. Deoxyribonucleic acid (DNA) content of vegetative and induced apices are similar. Shoot apices of vegetative plants contained little or no starch. However, shoot apices of plants grown at 42 °F accumulate large amounts of starch. Floral primordia which develop into functional flowers are glutted with starch, while floral primordia which abort are void of starch.
OCCURRENCE OF MONHYSTRELLA PLECTOIDES (NEMATODA: MONHYSTERIDAE) WITHIN THE WHITE OOGONIA OF CHARA ZEYLANICA
Authors: Harrington D. , Anderson R. G. , Bird G. W. , Mai W. F.
Published: August 2008

Monhystrella plectoides Cobb is reported within the white oogonia of two forms of Chara zeylanica Willd. This represents the first report of a nematode relationship with Chara. The nematode is apparently confined to the female gametangia, other parts of the plant organs being free of the organism.
STUDIES IN THE ARUNDINELLEAE (GRAMINEAE).: V. THE SERIES OF THE GENUS ARUNDINELLA
Authors: Phipps J. B.
Published: August 2008

The genus Arundinella is treated as consisting of 47 species (those listed by Phipps 1966) and is delimited after the manner of Bor (1955). There is no attempt here to resolve difficult specific limits.This paper presents the first key and classification into 15 series of all the Arundinella species in the world. It may be used in conjunction with Phipps (1966) which contains references to synonymy and generalised geographical distributions.
COLONY DIFFERENTIATION IN EUDORINA
Authors: Goldstein Melvin
Published: August 2008

A new pattern of colony differentiation was observed in a portion of a clone (5%) in the normally undifferentiated species, Eudorina elegans. The new form possesses somatic and generative cells arranged on opposite sides of the anterior–posterior axis of the colony and the somatic cells die gradually during colony maturation. The development and ultimate pattern of colony differentiation is described and compared with known patterns of differentiation in Eudorina illinoisensis and Eudorina (Pleodorina) californica. A possible mechanism to account for colony differentiation in Eudorina is discussed.
NOVA SCOTIAN FUNGI: GEOGLOSSACEAE
Authors: Grund Darryl W. , Harrison Kenneth A.
Published: August 2008

Recent studies in the mycological herbarium at Acadia University confirm previous reports and present additional data on the family Geoglossaceae occurring in Nova Scotia. This paper presents a key and detailed drawings of anatomical structures of 26 species in several genera of this family found in Nova Scotia, It is shown that one species name is being applied to species that are in different genera. One new species, Microglossum olivaceisquamulosum is described.
CYTOTAXONOMY OF FOLIOSE THISTLES (CIRSIUM SPP. AFF. C. FOLIOSUM) OF WESTERN NORTH AMERICA
Authors: Moore R. J. , Frankton C.
Published: August 2008

Four related Cirsium species of western North America are considered with respect to morphology, cytology and distribution: Cirsium acaulescens (2n = 34), C. congdonii (2n = 34), C. coloradense, and C. scariosum (2n = 34). A new Californian species, C. congdonii R. J. Moore & C. Frankton, is described. Phylogeny of these and other related species is discussed.
DEVELOPMENTAL POTENTIALITIES OF LEAF PRIMORDIA OF OSMUNDA CINNAMOMEA: THE INFLUENCE OF DETERMINED LEAF PRIMORDIA ON UNDETERMINED LEAF PRIMORDIA
Authors: Kuehnert Charles Carroll
Published: August 2008

In the fern Osmunda cinnamomea, leaf primorida may be excised and grown in sterile culture before or subsequent to their irreversible determination as leaves. It has been demonstrated that P3 primordia (third-oldest primordia) are not irreversibly determined as leaves at the time of excision for they exhibit a tendency to develop as shoots rather than leaves when cultured aseptically. When grown singly they become shoots 75.0% of the time; when grown in physiological contact as paired units they exhibit a tendency to become shoots at approximately the same level. The hypothesis that the active site of leaf determination is through the direct or indirect control of the shoot apical meristem is questioned and an alternative hypothesis is proposed which suggests that a morphogenetic factor is formed in older primordia which will diffuse to younger primordia to influence younger primordia to develop as leaves rather than shoots. The latter hypothesis is supported by experiments in which P3 primordia grown in physiological contact (as pairs) with P10 or P12 primordia produce more than twice as many leaves as unpaired or paired P3 primordia.
POLYPHENOLS AND DISCOLORATION IN THE ELM DISEASE INVESTIGATED BY HISTOCHEMICAL TECHNIQUES
Authors: Gagnon Camilien
Published: August 2008

Discoloration was produced in the xylem of seedlings of white elm (Ulmus americana) by injection of ethanol and buffer solutions; this was similar to the discoloration produced in elms infected by Ceratocystis ulmi. Histological changes produced during infection were studied. The distribution of polyphenols in healthy and diseased elms was compared by histochemical tests; the strong reaction in cells that in later stages of infection showed browning is an indication that pathological discoloration is due to oxidized phenolic compounds. These may originate by synthesis or by degradation of existing substances. Their role in the disease development may be to interfere with the sap movement either by their action on living cells or by their participation in the occlusion of vessels, and they may act also as toxins.
TWO SPECIES OF COPRINUS FROM ALKALI LAKES
Authors: Anastasiou C. J.
Published: August 2008

Two bipolar species of Coprinus are described from alkali lakes of British Columbia, C. amphibius sp. nov. and C. alkalinus sp. nov. Growth of C. alkalinus was found to be sensitive to variations in salt concentration of alkali lake water. Production of fruit bodies by Coprinus alkalinus is dependent on light. A spore color mutant segregating independently of mating types appears to be present in C. alkalinus.
Chemosystematic studies in the genus Picea (Pinaceae). III. The leaf oil of a Picea glauca × mariana hybrid (Rosendahl spruce)
Authors: Rudloff E. von , Holst M. J.
Published: August 2008

The terpene composition of the leaf oils of the Rosendahl spruce, white spruce, and black spruce as isolated from provenances derived from Cromwell, Minnesota, was determined by gas–liquid chromatography. The chemical composition was found to reflect the hybrid origin of the Rosendahl spruce. This confirms that the leaf oil composition of Picea species may serve as a biochemical character in chemo systematic studies.
The physiology of host–parasite relations. XIX. Further observations on nucleoprotein changes in wheat leaf nuclei during rust infection
Authors: Bhattacharya P. K. , Shaw Michael , Naylor J. M.
Published: August 2008

Cytophotometric measurements of DNA (Feulgen) and protein-bound lysine and arginine (fluorodinitrobenzene-Sakaguchi) were made on nuclei in mesophyll cells of infected and uninfected leaves of Little Club wheat at intervals of 2 to 4 days up to 13 days after inoculation with uredospores of race 15B of the stem rust fungus (Puccinia graminis tritici Erikss. and Henn.). No change in host DNA was found within 6 days after inoculation, but there were marked decreases in protein-bound lysine and arginine as early as 2 days after inoculation. The DNA/lysine and DNA/arginine ratios were higher in rust-affected host nuclei, but infection did not alter the ratio of protein-bound lysine to arginine. In another series of measurements it was shown that rust infection caused striking increases in the volume and the RNA and protein contents of host nucleoli. These changes persisted even in advanced infections.All the results are consistent with our earlier observations and indicate that profound changes in nuclear metabolism are induced by infection with the rust fungus.
A histochemical study of the shoot apical meristem of Rauwolfia with reference to differentiation of sclereids
Authors: Mia Abdul J. , Pathak Suman M.
Published: August 2008

The Rauwolfia apical meristem has three zones which are cytologically recognizable, viz. tunica, corpus, and pith-cell meristem. Histochemically, however, these zonations are not discernible. The entire meristem either reacts positively or negatively for a particular enzyme. The apical meristem and procambial strands give a strong positive reaction for cytochrome oxidase, succinic dehydrogenase, and total protein. The pith cells react positively with peroxidase, acid phosphatase, and phosphorylase. Alkaline phosphatase is distributed throughout the meristematic and non-meristematic areas of the shoot apex. Cells in these areas appear to give slight reaction for glucose-6-phosphatase and 5-nucleotidase. Activities of several enzyme systems, such as cytochrome oxidase, peroxidase, succinic dehydrogenase, and acid phosphatase, were localized in the sclereid initials. Commonly the sclereids give more intensified enzymatic reaction than the pith parenchyma cells.
Comatricha nodulifera, a new myxomycete from Texas
Authors: Wollman Constance , Alexopoulos Constantine J.
Published: August 2008

Comatricha nodulifera sp. nov., which developed on tree bark in a moist chamber, is described and its cultivation on agar media from spores discussed. This species differs from all other known comatrichas in bearing numerous, minute nodule-like swellings on the ultimate branches of the capillitium, a character which is stable when the organism is cultured on various media. The Plasmodium is an aphanoplasmodium.
Axillary bud traces in certain dicotyledons
Authors: Shah J. J.
Published: August 2008

The ontogenetic development of the axillary bud traces in two species of the family Verbenaceae, Clerodendrum inerme L. and C. splendens Gaertn. and one species of the family Myrtaceae, Syzygium cumini L., is described.Initially the two bud traces differentiate as branches of the leaf trace complex of the subtending leaf. Its further course in the bud may be due to direct differentiation of bud meristem cells as in Syzygium, or by the process of dedifferentiation and redifferentiation of certain sectors of the ground meristem intervening between the bud and the leaf trace of the subtending leaf as in Clerodendrum. Consequent to their further differentiation in the bud, the development of the primary vascular meristem of the bud occurs, initially as two arcs, later as an incomplete ring, and finally as a complete ring. It consists of residual meristem and procambium strands. The procambium strands form an anastomosing pattern of primary vascular system of the bud. Their ultimate origin can be traced to the two bud traces.An incorrect histogenic picture of the developing primary vascular system of a growing bud is obtained if one considers the vascular configurations of an arc or a complete or incomplete ring as bud traces. This histogenic development is a result of morphogenic interaction between the apical meristem of the bud and acropetally developing procambium strands of the bud trace. The vascular structures described as arcs, horseshoe-shaped, or ring are the phasic histogenic expressions of the gradual differentiation of the primary vascular system of the bud.
Comparative response of closely related species to reduced competition. I. Senecio sylvaticus and S. viscosus
Authors: Palmblad I. G.
Published: August 2008

A comparison of the reproductive and vegetative responses of Senecio sylvaticus and Senecio viscosus to the time and intensity of reduced competition is reported. The two species reacted similarly to thinning in terms of (1) reduced seed production per experimental population and increased seed production per individual, (2) reduced head production, (3) reduced vegetative dry weight, and (4) increased plant height.The two species of Senecio differed in their reaction to thinning in terms of (1) initial anthesis, (2) number of seeds per head, and (3) mortality. Thinning had no significant effect in altering the initial flowering of S. sylvaticus. Early thinning in S. viscosus advanced the flowering date while late thinning delayed flowering. S. sylvaticus was capable of increasing the number of seeds per head only if thinning occurred early, whereas the number of seeds per head in S. viscosus significantly increased at all thinning periods. Lastly, S. sylvaticus experienced much heavier mortality than S. viscosus.
Relative quantities of antifungal metabolites produced in resistant and susceptible soybean plants inoculated with Phytophthora megasperma var. sojae and closely related nonpathogenic fungi
Authors: Gray Griscelda , Klarman W. L. , Bridge Margaret
Published: August 2008

Resistant Harosoy 63 plants produced 7 times as much fungal inhibitor as susceptible Harosoy when both were inoculated with the soybean pathogen, P. megasperma var. sojae. When the challenging fungus was a nonpathogenic variety of P. megasperma, Harosoy 63 produced only twice as much inhibitor as Harosoy. A closely related fungus, P. cactorum, also nonpathogenic on soybean, stimulated equal amounts of inhibitor in both varieties. The three Phytophthora isolates did not differ significantly in their ability to stimulate inhibitor in Harosoy 63, but in Harosoy, both isolates of P. megasperma stimulated significantly less inhibitor than did P. cactorum. Inhibitor from the interaction of P. megasperma var. sojae × Harosoy 63 was most inhibitory to P. megasperma and least inhibitory to P. cactorum.
A new species of Columnea (Gesneriaceae) from Costa Rica
Authors: Raymond Marcel
Published: August 2008

A description is given of Columnea costaricensis Raymond, a new species of Gesneriaceae. The author suggests that, because of its unusual color, it may have a horticultural future.
Free sugars, amino acids, and soluble proteins in the embryo and female gametophyte of jack pine as related to climate at the seed source
Authors: Durzan D. J. , Chalupa V.
Published: August 2008

Non-stratified and dormant seeds from various geographic sources across the natural range of jack pine (Pinus banksiana Lamb.) were separated into embryo (diploid) and female gametophyte (haploid) and examined for their free sugars, free and bound amino acids, and soluble proteins. Climatic factors from not less than 8 and as many as 15 widely separated seed sources correlated well with most chemical components of the embryo and gametophyte. The composition of the dormant embryo was also highly correlated to levels of sugars and nitrogenous compounds in the female gametophyte. Climate at the seed source clearly affected the degree to which metabolism of carbon and nitrogenous compounds in the seed proceeded before and during incipient germination. Upon germination of seeds from one of the sources, the gametophyte was rapidly consumed, arginine level and protein pattern in the embryo changed, many soluble proteins disappeared and amide content increased greatly.
Some factors affecting growth of embryos of Dendrophthoe falcata in cultures
Authors: Bajaj Y. P. S.
Published: August 2008

This investigation deals with the effects of light, endosperm, endosperm extract, and position of the embryo on germination in vitro of the embryos of Dendrophthoe falcata, a stem-parasitic mistletoe.If the embryos are cultured while still enclosed in the endosperm, germination is delayed, the holdfast is massive, and occasionally there is a formation of buds on the holdfast. These effects have also been induced by the addition of endosperm extract to the medium. The embryos fail to germinate if they are completely immersed in the medium. At early stages, light does not seem to have any beneficial influence, but for healthy growth of the seedling, it is indispensible.
An analysis of vegetation–environment relationships in Saskatchewan sloughs
Authors: Walker B. H. , Coupland R. T.
Published: August 2008

This study examined the relationships between the distribution of herbaceous species and some of the major environmental factors in sloughs. Frequency distribution of species was studied in 64 stands. Environmental data, collected in 40 of these, included weekly readings of water level, fortnightly readings of pH and total dissolved solids in water, and texture and organic matter content of topsoil and subsoil. An association table of 24 leading dominants, arranged so that strongly associated species were close together, corresponded closely to their observed order along a moisture gradient. Environmental scalars were constructed to combine data on pH and total dissolved solids, as well as initial water depth and rate of water loss. The soil data showed very little association with species distribution. Synthetic scalars for water regime and for water chemistry were plotted against one another to obtain an arrangement of stands. Plotting the frequency distribution of the leading dominant species over the environmental arrangement of stands showed most of the species to be strongly affected by the water regime and somewhat less affected by salinity. A few were restricted to a very narrow range of one of these factors, while others flourished in all segments of the environment. The relationships suggested by this analysis are largely in agreement with those suggested by the vegetation analysis alone.
Transfers from Physaria to Lesquerella (Cruciferae)
Authors: Mulligan Gerald A.
Published: August 2008

Evidence is presented supporting the transfer of four species of Physaria to Lesquerella, as L. geyeri (Hooker) Mulligan, comb. nov.; L. oregona (Watson) Mulligan, comb, nov.; L. alpestris (Suksdorf) Mulligan, comb, nov.; and L. kingii Watson var. cordiformis (Rollins) Maguire and Holmgren. The following chromosome numbers are reported: L. geyeri, 2n = 8; L. oregona, 2n = 8; L. alpestris, 2n = 49–52 and 67–70; L. kingii var. cordiformis, 2n = 10.
Species of Puccinia attacking Veroniceae (Scrophulariaceae)
Authors: Savile D. B. O.
Published: August 2008

Microcyclic rusts on three host groups are discussed. Alpine Veronica spp. harbor: Puccinia albulensis Magn. ssp. albulensis on V. alpina (Alps, Scandinavia, Iceland, ?Labrador), V. wormskjoldii (Alaska to Colo.), V. cusickii (Wash.); P. a. ssp. cascadensis Savile ssp. nov. on V. cusickii (B.C., Wash.); P. rhaetica E. Fisch. ssp. rhaetica on V bellidioides (Alps); P. r. ssp. americana Savile ssp. nov. on V. cusickii (Wash., Ida.), V. wormskjoldii (Wyo.). Paederota, Veronicastrum, and lowland to montane Veronica harbor: P. veronicarum DC. on Veronica latifolia, V. ponae (Europe), and doubtfully Veronicastrum sibiricum (E. Asia), V'astrum virginicum (E. North America); P. veronicae Schroet. on V. montana (Europe), and doubtfully on V. morrisonicola (Formosa), V. spuria (Poland), V. stelleri (Japan); P. veronicae-longifoliae Savile sp. nov. on V. longifolia, V. spicata (Europe); P. paederotae Savile sp. nov. on Paederota ageria (Yugoslavia). Besseya, Synthyris, and Lagotis harbor: P. wulfeniae Diet. & Holw. ssp. wulfeniae on S. reniformis vars. (Ore., Calif.); P. w. ssp. saximontana Savile ssp. nov. on B. wyomingensis (Wyo.), and intergrading rusts on B. rubra (E. Wash.), S. missurica, S. platycarpa (Ida.); P. sp. near wulfeniae on L. clarkei (Sikkim); P. acrophila Peck on B. alpina (Colo.), B. ritteriana (Colo.), B. wyomingensis (Mont., Wyo.), S. laciniata (Utah), S. pinnatifida (Wyo., Utah), S. stellata (Wash.); P. gymnandrae Tranz. ssp. gymnandrae on L. minor (Urals), L. ? integrifolia (Pamir, Turkestan, Kashmir); P. g. ssp. yunnanensis Savile ssp. nov. on L. thomsonii (Tibet), L. yunnanensis (Yunnan); P. g. camscliatcensis Savile ssp. nov. on L. glauca (Kamchatka); P.g. ssp. alascensis Savile ssp. nov. on L. minor (Alaska).
A malate dehydrogenase of high molecular weight, from bean leaves
Authors: Habig William , Racusen David
Published: August 2008

Two forms of malate dehydrogenase (MDH) of widely differing molecular weight were found in primary leaves of Phaseolus vulgaris. Their molecular weights were estimated as 69 000 and 275 000 by sucrose density gradient centrifugation. The ratio of these two forms followed an orderly course in which the high molecular weight MDH increased from near zero in very young leaves to about 35% of the total MDH activity in leaves older than 2 weeks. Conditions which cause the high molecular weight MDH to dissociate to active normal molecular weight enzyme are discussed.
A comparison of cambial activity of white spruce in Alaska and New England
Authors: Gregory Robert A. , Wilson Brayton F.
Published: August 2008

White spruce trees (Picea glauca (Moench) Voss) producing annually the same number of tracheids had a much shorter season for cambial activity in Alaska (65° N) than in New England (43° N). We counted the number of potential dividing cells in the cambial zone (NCZ) and estimated the rate of cell division by determining the percentage of cambial zone cells in mitosis (MI) for trees of different vigor (annual tracheid production) from each region during the early summer period of relatively constant mitotic activity. Within each region, NCZ was dependent on tree vigor and MI was independent of tree vigor. Rate of tracheid production was higher in Alaskan trees because of their higher rate of cell division (higher MI).
Three morphological mutants in Avena strigosa
Authors: Dyck P. L.
Published: August 2008

Three morphological mutants in Avena strigosa, produced by treatment with X-rays, are described. Inheritance studies indicated that the mutant characters cluster panicle (pt-5), floretless (fl), and multiglume (mg) result from single gene mutations. Genes fl and mg were inherited independently.
The occurrence of Leptosphaeria maculons on Thlaspi arvense
Authors: Petrie G. Allan , Vanterpool T. C.
Published: August 2008

Ascocarps of Leptosphaeria maculons (Desm.) Ces. & de Not. have been collected for the first time on Thlaspi arvense L. Evidence is presented to demonstrate that L. maculans is the perfect state of a strain of Plenodomus lingam (Tode ex Fr.) Höhn. found commonly in Western Canada on T. arvense and other members of the Cruciferae.
Activity of N-ribosyl-adenosine ribohydrolase in potato leaves in response to Phytophthora infection
Authors: Page O. T. , Clark M. C.
Published: August 2008

Early response of potato leaves to infection by the fungus Phytophthora infestans resulted in an accumulation of adenine in leaf tissue. Mycelium of P. infestans and ground potato leaf tissue converted adenosine to hypoxanthine and adenine, respectively, when fungal and host cells were incubated together. The influence of adenosine concentration, pH, and temperature on the conversion of adenosine to adenine by potato leaf extracts was examined; conversion occurred more rapidly at 70 °C than at 20 °C. The enzyme effecting the conversion was determined to be N-ribosyl-adenosine ribohydrolase. Preparations of this enzyme were chromatographed and retained their capacity to hydrolyze adenosine.
On some relationships between Avena sativa and A. fatua (Gramineae) as studied from Canadian material
Authors: Baum Bernard R.
Published: August 2008

Many authorities consider that Avena sativa and A. fatua constitute a single species. This attitude is based mainly on morphology, because of the existence of different intermediate forms, and partly on the belief that A. sativa is a product of selection by man from A. fatua. More recently, because of the absence of chromosomal differentiation cytogeneticists have tended to support this contention that A. sativa and A. fatua constitute a single species. This paper reports the discovery of two new characters based on the detailed micromorphology of the lodicules and epiblasts. These new characters per se as well as in combination with other macromorphologic characters proved to be most reliable for the discrimination and recognition of these two taxonomically specific units. Observations on Canadian material revealed spontaneous F1 hybrids or F1-like phenotypes. An attempt is made to correlate the available cytologic and genetic data with the present findings. A one-way and restricted gene flow from A. fatua to A. sativa is assumed to occur between these two coexisting species.
Morphology and cytology of aeciospores and aeciospore germ tubes of host-alternating and pine-to-pine races of Cronartium flaccidum in northern Europe
Authors: Hiratsuka Y.
Published: August 2008

Host-alternating and pine-to-pine races of Cronartium flaccidum (Alb. & Schw.) Wint. (Peridermium pint Lév.) on Pinus sylvestris L. from northern Europe can be distinguished by differences in the morphology and cytology of aeciospores and aeciospore germ tubes. In the host alternating race, aeciospores were binucleate and, upon germination, two nuclei migrated into the germ tube. The nuclei remained undivided during migration. Septa were not observed and branching was dichotomous and irregular. Growth of germ tubes was indeterminate.In the pine-to-pine race, aeciospores were mostly binucleate but variable proportions (16% to 28%) were uninucleate. Upon germination nuclear division and septum formation occurred and the germ tubes were transformed into two, three, or four cells, each of which usually contained one nucleus. The germ tubes were straight and seldom exceeded 200 μ in length. One to three branches were observed. Despite the absence of basidiospores, the pine-to-pine race of C. flaccidum (= P. pini) is interpreted as having an endo-type life cycle with or without nuclear fusion and typical meiosis.
The effect of two audible sound frequencies on the germination and growth of a spring and winter wheat
Authors: Weinberger Pearl , Measures Mary
Published: August 2008

The effect of sound of 5 kc/s and 12 kc/s on the germination and growth of grains and seedlings of vernalized spring (Marquis) and winter (Rideau) wheats was investigated. Untreated controls were simultaneously followed, and all experimental series were replicated at least three times. Growth cabinets were systematically interchanged with the replications to eliminate other variables. Sound at both frequencies significantly stimulated the germination of Marquis grains maintained at 2° and 10 °C. At 25 °C the rate of germination was unchanged. An indication of a slightly elevated germination rate was observed in Rideau grains held at 2° and exposed to 5 kc/s. Neither frequency significantly affected germination at 10° or 25 °C.Growth of plants derived from fully vernalized grains was followed by measuring total plant height, wet and dry weight of "tops", number of roots, and their fresh and dry weights. Rideau wheat grew more vigorously at both sound frequencies. Continuous exposure to 5 kc/s both during vernalization and subsequent growth resulted in a 200% or greater increase in all parameters followed. The growth response of Marquis wheat was dependent upon treatment. Some conditions of sound exposure accelerated growth, whereas in others growth was depressed.
The generic concepts of Diplorhinotrichum and Dactylaria, and a new species of Dactylaria from soil
Authors: Bhatt G. C. , Kendrick W. Bryce
Published: August 2008

A new hyphomycete described from soil bridges the gap between the form generic concepts of Diplorhinotrichum Höhn. and Dactylaria Sacc., and the two genera are united under the earlier name. Nine new combinations into Dactylaria are made.
The effect of relative humidity and temperature on survival and growth of Botrytis cinerea and Sclerotinia sclerotiorum
Authors: Berg L. Van Den , Lentz C. P.
Published: August 2008

Tests with mycelium and conidia of five strains of Botrytis cinerea and mycelium of three strains of Sclerotinia sclerotiorum have shown that survival and growth of these organisms depended on relative humidity, temperature, and type and strain of organism. Survival of mycelium of both organisms in the absence of nutrients, for example, varied from 12 months at 95–100% relative humidity and 0 °C to less than 1 month at below 95% relative humidity and 20 °C, depending on strain. When nutrients were present growth occurred at solution equilibrium relative humidities over 93%; at equilibrium relative humidities below 93% no growth occurred and mycelium survived only up to 1 month. Growth rates of all strains of both organisms were similar between −0.8 and 35 °C with maximum rates at about 20 °C. Results also showed that mycelium and conidia of B. cinerea survive under the conditions at which vegetables are usually stored but that mycelium of S. sclerotiorum in most instances does not.
A new species of Aspergillus versicolor group—A. lucknowensis spec. nov., from Indian alkaline soils
Authors: Rai J. N. , Tewari J. P. , Agarwal S. C.
Published: August 2008

The new species, Aspergillus lucknowensis spec. nov., characterized by the presence of bright-yellow mycelium and very late-developing yellow-green conidial heads, is described from Indian 'usar' soils (pH 8.0).