bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytochemical localization of peroxidase A′ in developing stem tissues of extreme dwarf tomato
Authors: Gordon Albert R. , Alldridge Norman A.
Published: September 2008

Four soluble and two cell wall bound peroxidases account for most of the peroxidase activity in sections of tomato stem tissues. These peroxidases differ in heat sensitivity when incubated in acidic media. Two of the six peroxidases are inactivated at higher temperatures in tissue sections than in tissue extracts treated in the same way. Under defined conditions of heating, all but one of the tomato peroxidases can be inactivated in tissue sections and extracts. A cytochemical peroxidase method is described and used to determine the cellular distribution of this heat-stable peroxidase in developing stem tissues. Changes in the activity and cellular distribution of this peroxidase occur in tissues of the stem during development.
Rhizophydium patellarium and R. capillaceum (Chytridiales)
Authors: Barr D. J. S.
Published: September 2008

The morphology and physiology of two pure culture isolates of Rhizophydium patellarium Scholz have been compared with two isolates of R. capillaceum Barr. The species differ in method of zoospore discharge: R. patellarium by dissolution of part of sporangium wall and R. capillaceum by dissolution of papillae. In physiology there are differences between isolates of each species but there is no useful physiological criterion for distinguishing species. It is proposed to reduce R. collapsum Karling as a synonym of R. patellarium.
Production of the nutritional requirements for growth of Cronartium ribicola by a nonhost species
Authors: Harvey A. E. , Grasham J. L.
Published: September 2008

Tissue cultures derived from the cortex of Pseudotsuga menziesii provided the nutrients required to support growth of Cronartium ribicola, a rust fungus. In nature, this obligate parasite is sustained by Pinus and Ribes spp. only. The pathogen was separated from its source of nutrients by a cellulose membrane. These experiments demonstrated that the nutritional factors required for growth of this rust are not host-specific and have small molecular size.
Callose in megasporogenesis of Diarrhena (Gramineae)
Authors: Schwab Charlotte A.
Published: September 2008

The presence of callose in cell walls during megasporogenesis is reported in Diarrhena (Gramineae). This phenomenon was previously unreported for the family. The appearance and distribution of callose beginning at the megasporocyte stage was studied using the callose – aniline blue fluorescence method on paraffin sections. This information greatly aided the interpretation of the developmental sequence.
The genus Arthroderma Berkeley
Authors: Padhye A. A. , Carmichael J. W.
Published: September 2008

A key to 13 known species is given, followed by descriptions and illustrations of the perfect and imperfect states of each species. The imperfect states are referred to the form genera Chrysosporium and Trichophyton. The name Trichophyton flavescens is proposed for the conidial state of Arthroderma flavescens.
Flavonoid components of Dicentra canadensis (Fumariaceae)
Authors: Fahselt Dianne
Published: September 2008

A survey was made of the flavonoid components in Dicentra canadensis to investigate its relationship with other species in the genus. This study supports the view that D. canadensis is most closely allied to D. cucullaria. Flavonoids suggest an even closer alliance between the two than does morphology, while alkaloid data reported in the literature would suggest a more distant one. Thus, the degree of relationship supported by morphological evidence is intermediate to what is supported by two different types of biochemical evidence. A large proportion of the total flavonoids in D. canadensis is detected with considerably less than 100% frequency within the species. This variability may reflect some genetic variability between populations, and is almost certainly due in part to the difficulty in detection of weaker spots.
Anatomical and cytological studies of an intergeneric hybrid, Oryzopsis hendersonii × Stipa lemmonii (Gramineae)
Authors: Spellenberg Richard W. , Mehlenbacher Lyle E.
Published: September 2008

A hybrid between Oryzopsis hendersonii and Stipa lemmonii is reported and formally described. In a population in central Washington where the two parent species are sympatric 12 hybrid plants were found. The hybrids are morphologically and anatomically intermediate; O. hendersonii, which occupies drier sites, has xeromorphic modifications in the leaves not found in S. lemmonii. Both parents and the hybrid have 2n = 34 chromosomes. Meiosis in the hybrid is abnormal with some unpaired chromosomes, clumping of the chromosomes at diakinesis, and lagging univalents at later stages. Univalents tend to divide synchronously at anaphase I, following the division of bivalents. An average of about 11 bivalents is determined. These studies may be interpreted as supporting the transfer of this Oryzopsis to Stipa which is presented here, and it is suggested that several species of Oryzopsis have evolved independently from stipoid stock.
Physiologic races of wheat stem rust in Canada from 1919 to 1969
Authors: Green G. J.
Published: September 2008

The races of wheat stem rust found in Canada and identified by the "standard" and "formula" methods are described. Seven races or race groups made up 90.8% of the isolates. In 1964 a new system of race identification was introduced. It makes use of virulence formulas consisting of the numbers of effective resistance genes in the numerator and ineffective genes in the denominator. Resistance genes Sr6, Sr8, Sr9a, Sr9b, and Sr13 confer resistance to most isolates obtained since 1964, but no single gene confers resistance to all isolates. Experience shows that 250 isolates per year are sufficient to establish the trends of prevalence of the main races. The detection of rare, new combinations of virulence requires screening varieties carrying combinations of resistance genes. The main races in the past 50 years have been 56 and 15B. Race 56 is uniform with a single subrace but 15B is variable with many subraces. There is no evidence that unnecessary virulence is harmful or that "stabilizing selection" is operative in Canada, nor is there evidence that virulence on resistance genes Sr6 and Sr11 is harmful to the rust.
The ultrastructure of Arceuthobium pusillum
Authors: Tainter F. H.
Published: September 2008

The endophytic system (ES) of Arceuthobium pusillum in Picea mariana, a compatible host, ramified throughout branchlets composing witches' brooms, and its cells contained numerous nonmembranebound droplets composed largely of neutral fats which occupied much of the cytoplasmic volumes and which persisted in senescent cells. The ES in the less compatible Larix laricina was found to persist mostly in tissues adjacent to and in spur shoots, and, in less vigorous infections, it accumulated fewer lipid droplets. In more successful infections of larch, many droplets were observed. Although the droplets probably serve for storage of high-energy fats, their accumulation in L. laricina appears to be reflected in the degree of success which the parasite has in this host. The more successful the infection, the more abundant are lipid droplets. Rapid lipid synthesis by the parasite may help to maintain a sharp carbohydrate diffusion gradient from host to parasite. The lipid droplets in both hosts were often in physical contact with smaller, single membrane-bound, evenly staining bodies which may have been involved in synthesis or use of these lipids. Germinating seeds, aerial shoots, and ES of the parasite in both hosts contained functional chloroplasts that structurally resemble those in the Gramineae that use the C4-dicarboxylic acid pathway.
Grasslands of the North Fork Valley, Glacier National Park, Montana
Authors: Koterba Wayne D. , Habeck James R.
Published: September 2008

A series of 40 grassland communities occurring in the North Fork Valley in Glacier National Park was subjected to detailed phytosociological investigation. These grasslands are somewhat phytogeographically isolated from other northern Rocky Mountain grasslands in Washington, Idaho, and Montana in the United States, and from the Alberta fescue grasslands in Canada. Compositionally, the North Fork grasslands display features characteristic of grassland vegetation on both the west and east sides of the Continental Divide. The four major grass species achieving dominance in the North Fork Valley are Agropyron spicatum, Festuca idahoensis, Festuca scabrella, and Danthonia intermedia. Environmental factors possibly important in the distribution, composition, and maintenance of these grasslands are discussed.
The influence of fertilization with KNO3 and NH4NO3 on some nitrogen fractions in tomato seedling tissues
Authors: Ward Gordon M. , Miller Marcia J.
Published: September 2008

The application of KNO3 and NH4NO3 fertilizers to tomato seedlings growing in soil resulted in the rapid absorption and conversion of nitrogen in a 24-h period. Total nitrogen increased in all tissues but nitrate tended to accumulate more in conductive tissue. Conversion of NH4NO3 to amino acids proceeded faster than that of KNO3 and produced higher levels of most free amino acids 24 h after feeding. However, proline, aspartic acid, and some other amino acids in some tissues were produced more abundantly from KNO3.
Plant indicators of pH and water level in peatlands at Candle Lake, Saskatchewan
Authors: Jeglum John K.
Published: September 2008

Quantitative data on vegetation, depth to water level, and pH of both moist peat and water from 113 stands of peatland near Candle Lake, Saskatchewan, are used to demonstrate relationships of peatland species to classes of pH and depth to water level, and to recognize plant indicators for the various classes. Weighted average and similarity coefficient techniques are used to estimate pH and depth to water level from total species lists and restricted lists of important species. Total species lists, combined with either weighted average or similarity coefficient techniques, yield indices with the highest correlations with the true values and the lowest standard errors of estimate. Depth to water level and pH are recognized as two important environmental correlates with floristic and vegetational variation in peatlands.
Host–parasite relations in mycoparasite. I. Fine structure of host, parasite, and their interface
Authors: Manocha M. S. , Lee K. Y.
Published: September 2008

A mycoparasite, Piptocephalis virginiana, shows resemblance to other fungal parasites of higher plants in the fine structure of hyphae and haustoria. The mode of penetration of the host cell, Choanephora cucurbitarum, probably involves mechanical forces. Although the presence of a cell wall degrading enzyme was not detected by conventional techniques, its role in penetration can not be ruled out. A collar around the haustorial neck is formed as an extension of the host cell wall. No papilla was detected although appressorium was seen during penetration. The young haustorium is enclosed in highly invaginating plasmalemma of the host cell and numerous cisternae of endoplasmic reticulum (ER). Appearance of an electron-dense sheath around the mature haustorium seems to coincide with the disappearance of cisternae of ER from the host cytoplasm in the vicinity of the haustorium. The role of host cytoplasm, particularly of ER, in the development of the sheath is discussed. Extensive accumulation of spherosome-like bodies, containing lipids, is found in haustorium, parasite, and host hypha.
Notes on Hyphomycetes. II. Additions to the genus Sciniatosporium Kalchbrenner
Authors: Morgan-Jones G.
Published: September 2008

Five species which were previously accepted in the genus Stigmina Sacc., and one in Thyrostroma Hohnel, are transferred to Sciniatosporium Kalchbr. S. pusillum (Karst.) Morgan-Jones and S. vleuge-lianum (Bubák) Morgan-Jones are redescribed and illustrated.
Fluoride injury symptoms in epiphytic lichens and mosses
Authors: LeBlanc Fabius , Comeau Gilberte , Rao D. N.
Published: September 2008

This study was conducted in Arvida, Quebec, where volatile fluorides and HF are released into the atmosphere from an aluminum factory. Lichen and moss-bearing bark discs, cut out from trees in an unpolluted area, were fixed in groups of six in rectangular wooden boards. All discs were photographed in color as well as in black and white. Fifteen sites, in addition to a control site, were selected in different directions from the factory. At each site two boards were fixed with nails in a vertical position at a height of 8–10 m on a tree. One board was removed after 4 months exposure and the other after 12 months. The lichens and mosses exposed in control and polluted areas were compared with respect to their color, external morphology, plasmolysis in algal cells, loss of green color, the nature of reactions towards neutral red and 2,3,5-triphenyl-2H-tetrazolium chloride (TTC), absorption spectra of chlorophyll, and fluoride concentration. Results indicate that F-pollution affects moisture balance, causes chlorophyll damage, and produces other symptoms of injury which could lead to ultimate death of these organisms.
Gibberellic acid: effect on genetic tumor induction
Authors: Ames Ira H.
Published: September 2008

Young seedlings of the amphiploid Nicotiana suaveolens × N. langsdorffii, grown aseptically on nutrient medium, were treated with several concentrations of gibberellic acid (GA3). The incidence of tumor formation was scored for 18 days subsequent to exposure. At a concentration of 5 × 10−3 M, GA3 caused a striking reduction in the rate of tumor formation and a marked enhancement of stem growth in this tumor-prone amphiploid. These results are discussed in relation to the problem of the trigger mechanism for tumor induction in Nicotiana hybrids.
Natural pigment differences distinguish first and sequent periderms of conifers through a cryofixation and chemical techniques
Authors: Mullick D. B.
Published: September 2008

Field observations revealed distinctness of the first and sequent periderm pigmentation in each of 40 species from 13 genera of conifers. These distinctions in Abies amabilis (Dougl.) Forbes, Abies grandis (Dougl.) Lindl., Thuja plicata (Donn), and Tsuga heterophylla (Raf.) Sarg. were confirmed by a cryofixation and chemical techniques. The former technique depends upon fixation of tissues by freezing, and microscopic observation of cryostat sections in a frozen state, thus revealing the natural color of the pigments. The first periderm of the aforementioned four species is dark brown. It is replaced invariably by a reddish sequent periderm which always abuts the rhytidome. Additional reddish sequent periderms may continue to arise producing an ever-thickening rhytidomal zone. A second type of sequent periderm, dark brown in color, was found in three of the four species studied. This periderm, whenever present, was found abutting a reddish periderm and never abutting the rhytidome. The pigments are localized exclusively in phellem. The significance of the brownish sequent periderm in rhytidomal scaling and en masse sloughing, and its similarities to the first periderm are discussed.
Effect of intensity and quality of light on peroxidase activity associated with Septoria leaf spot of tomato
Authors: Benedict W. G.
Published: September 2008

Extracts of tomato (Lyeopersicon esculentum Mill. cultivar Heinz 1350) leaves infected by Septoria lycopersici Speg. were examined for peroxidase activity throughout the period of infection and disease development. These experiments were made to determine whether peroxidase activity was influenced by light, and, if so, the degree of effect of various wavelengths and intensities, other environmental conditions being constant. Consequently, paper electrophoresis scans of peroxidase isozymes showed a bimodal pattern of a conspicuous increase in staining intensity reflecting a high level of enzymatic activity of major components in leaves 4 days after their inoculation with the fungus. At 6 days minimal values were obtained, whereas somewhat enhanced isozyme activity occurred at later stages in the progression of the disease and the maturation of pycnidia and pycnospores. As well, decreased light intensity increased both the severity of the disease and the peroxidase activity in the infected leaf. This effect of light intensity was most evident 10 days after inoculation. Furthermore, treatment with various wavelengths of light produced the most marked effects on enzyme activity in the later rather than in the earlier stages of disease development. Maximal peroxidase activity occurred 10 days after inoculation, with a major peak in green light and a second peak in red light. These results indicate that the light regime is an important factor to consider in evaluating not only symptom expression but also analyses of the enzyme activity in this leaf spot disease.
Phloem in the haustorium of Castilleja (Scrophulariaceae)
Authors: Kuijt Job , Dobbins David R.
Published: September 2008

This note documents for the first time the presence of phloem in the haustorium of Castilleja sulphurea Rydb. From electron microscope studies the phloem was found to occur in the internal portion of the endophyte and on the periphery adjacent to cortical cells of the host.
Protein bodies from the cotyledons of Cucurbita maxima
Authors: Lott John N. A. , Larsen Per L. , Darley James J.
Published: September 2008

The structure of protein bodies from cotyledon tissue of dormant squash seeds was studied using several different preparative techniques. Four major components, the proteinaceous matrix, the protein crystalloid, the soft globoid, and the globoid crystal were found and verified to be present in protein bodies from the large mesophyll cells. Some of these four components were found to be absent in protein bodies of epidermal cells or in protein bodies near the nucleus of mesophyll cells. The globoid crystal, which was hard and electron dense after osmium fixation, is probably the site of phytin storage. The globoid crystal was usually surrounded by the soft globoid, a material of undetermined composition which tended to smear during freeze-etching. Some protein bodies contained several of these globoid regions although most protein bodies seemed to have only one globoid region. One or several protein crystalloids were usually found in protein bodies. Both the protein crystalloids and the globoid regions were surrounded by a proteinaceous matrix substance.Glutaraldehyde–permanganate fixation of tissue clearly showed the presence of the proteinaceous ground substance and the protein crystalloid but the globoid structures were absent. In tissue chemically fixed with glutaraldehyde–osmium all four components were sometimes found but interpretation, on the basis of this fixation alone, was difficult because of the presence of fixation artifacts. Isolation of protein bodies from cotyledon tissue made faster and better quality osmium or glutaraldehyde–osmium fixations possible. In such protein body pellets all four components were seen. Freeze-etching of tissue verified the presence of the globoid crystal and the soft globoid in most protein bodies from cotyledon mesophyll cells. In dormant seed tissue the two proteinaceous components usually were not distinguishable by the freeze-etching technique however. Thus only through the use of several different preparative techniques was it possible to locate and verify the presence of the various structural components in protein bodies from squash cotyledons.
Changes in chlorophyll and carotenoid content in oats associated with the expression of adult plant resistance to stem rust conferred by gene pg-11
Authors: Harder D. E. , Martens J. W. , McKenzie R. I. H.
Published: September 2008

The expression of adult plant oat stem rust resistance conferred by gene pg-11 is associated with a reduction of chlorophyll and carotenoid pigments in the leaf and stem tissue. Seedlings that possess gene pg-11 are susceptible to stem rust and have near normal pigment levels but with increasing age the pigment content decreases more rapidly than in plants without the gene and the plants become moderately resistant to stem rust. The ratio of chlorophyll to carotenoids remains unchanged at all stages of plant development. This gene has effects unlike any other known gene for stem rust resistance in oats.
Electrical stimulation and its effects on growth and ion accumulation in tomato plants
Authors: Black J. D. , Forsyth F. R. , Fensom D. S. , Ross R. B.
Published: September 2008

The effect of small increments of direct current on the growth and ion uptake in Scotia tomato plants was determined. The natural endogenous current in the plant was first assessed and the current applied to reinforce or oppose the natural with three treatment durations per day. Significant increases in linear growth (5 to 30%) were obtained and also significant increases in uptake by the plants of K, Ca, and P when currents were between 15 and 3 μA per plant with the plant negative to the ground. A reduction in growth occurred when the plants were treated with 15 μA positive to the ground or with any currents of magnitude greater than 30 μA per plant. The increased ion accumulation seems not to be merely a passive movement under the applied potential, and it is thought that small currents may stimulate active ion pumps or alter the internal distribution of growth-regulating compounds in a somewhat erratic manner.
In vitro growth and differentiation of Gladiolus plants from callus cultures
Authors: Simonsen J. , Hildebrandt A. C.
Published: September 2008

Callus was induced from isolated gladiolus cormel stem tips on modified Murashige and Skoog media. The callus was then induced to differentiate virus-symptomless plants with corms. Morphogenesis from the callus included meristematic zones on or within the callus, organoids with vascular tissue, stems, leaves, and plants with roots. Callus production and differentiation of plants were more frequent on agar than in liquid media.
Increased participation of pentose phosphate pathway in response to afterripening and gibberellic acid treatment in caryopses of Avena fatua
Authors: Simmonds J. A. , Simpson G. M.
Published: September 2008

The rates of oxygen consumption of dormant and non-dormant excised embryos of Avena fatua L. before germination are similar. Gibberellic acid (GA) treatment stimulates germination of dormant embryos without affecting oxygen consumption. Thus dormancy is not the result of restricted oxygen uptake. The fat content of dormant and non-dormant caryopses remains constant during germination. Dormant and non-dormant embryos have respiratory quotients near unity supporting the hypothesis that starch degradation occurs before germination. 6-Phosphogluconate dehydrogenase, a key enzyme of the pentose phosphate pathway, is present in dormant and non-dormant dry embryos but the pre-germination C6/C1 ratio of non-dormant embryos is markedly lower than that of dormant embryos, indicating a greater participation of the pentose phosphate pathway in the respiratory metabolism of non-dormant embryos. Release from dormancy is associated with a shift in metabolism from the glycolytic pathway to the pentose phosphate pathway. GA treatment, which stimulates germination of dormant embryos, causes a similar qualitative change in the oxidative metabolism of dormant embryos. Thus the action of GA is to cause the increased degradation of glucose via the pentose phosphate pathway, which is an essential step in the preparation for germination.
An addition to the genus Coryneum Nees ex Fr.
Authors: Morgan-Jones G.
Published: September 2008

Exosporium calophylli Sydow is considered best classified in Coryneum Nees ex Fr., and is transferred to that genus. The fungus is redescribed and illustrated.
Observation of plant roots in situ
Authors: Waddington J.
Published: September 2008

A technique is described which permits the determination of root penetration, distribution, and density with minimal disturbance to the plant. A small diameter tunnel is made in the soil and fitted tightly with a glass or transparent plastic tube. A fiber optics probe is used to observe the arrival of roots at the wall of the tube at various depths and to estimate their distribution and density. The probe consists of a light source and fiber bundle for illumination, a coherent fiber bundle for image transfer to the surface, a right angle viewing attachment at the objective end, and adjustable lenses.
Genera coelomycetarum. I. Urohendersonia
Authors: Raj T. R. Nag , Kendrick Bryce
Published: September 2008

Study of type material of Urohendersonia platensis, U. indica, and U. stipae reveals that structures described by their original authors as ‘basidia’ or ‘pedicels’ (in contemporary parlance, conidiophores) are, in fact, apical conidium appendages. The true conidiophores and the processes of conidiogenesis are described and illustrated. Urohendersonia has unilocular, ostiolate pycnidia producing three-septate, colored conidia that are enclosed from an early stage of development in a sheath which extends apically as a hyaline, filiform process. Urohendersonia and Hendersonia are delineated. Revised descriptions are given for Urohendersonia and its four species. A fifth species, U. mysorensis, is described as new. A key to the five species is given.
Oligocene woods from the Cypress Hills Formation in Saskatchewan, Canada
Authors: Roy S. K. , Stewart W. N.
Published: September 2008

This is a report of investigations of the petrified woods from the Cypress Hills Formation (Oligocene) of Saskatchewan. Families represented are Pinaceae (Pinoxylon hanlinei sp. nov.), Taxodiaceae (Sequoioxylon gypsaceum (Gothan) Greguss), Magnoliaceae (Magnolioxylon michelioides Hofmann), Simaroubaceae (Ailanthoxylon canalosum sp. nov.), Hamamelidaceae (Liquidambaroxylon speciosum Felix), and Juglandaceae (Eucaryoxylon canadensis sp. nov.). It is interesting to note here that except for the Pinaceae none of these families is now a part of the flora of this region. Presently genera of the other families occur in the eastern and southwestern United States, in the southeastern part of Canada (Carya), or in eastern Asia.
Palynology of Oligocene sediments from central British Columbia
Authors: Piel K. M.
Published: September 2008

Plant microfossils have been recovered from Oligocene sediments which outcrop along the Fraser River in the central interior of British Columbia, Canada. The sediments are composed of interbedded clays, sands, gravels, and lignites which were deposited as a part of an ancestral Fraser River system.The most commonly encountered members of the assemblage are Quercus, Alnus Carya, Liquidambar, Ulmus/Zelkova, Juglans, Pterocarya, Osmunda, and members of the Taxodiaceae, with infrequent occurrences of Engelhardtia, Prosopis, ?Psilotum, Ephedra, and ?Dorstenia. This assemblage suggests a warm temperate to near subtropical climate. A warm polar sea, a lowered Coast Range to the west, and a greater elevation of the Rockies to the east are suggested as a possible explanation for the climate.One new genus and 11 new species have been erected. Several species, including Prosopis quesneli, Diervilla echinata, Triporate B, and Taxodium rousei appear to be restricted to these beds, and may well be good index fossils for the Oligocene of western Canada.
Conidium ontogeny in Coelomycetes. II. Some Melanconiales which possess phialides
Authors: Morgan-Jones G.
Published: September 2008

An illustrated account of conidium ontogeny is given for Colletotrichum spp., Cylindrogloeum trillii (Ell. and Everh.) Arx, Discogloeum veronicae (Libert) Petrak, Gloeosporidiella spp., Rhynchosporina meinersii (Sprague) Arx, Monostichella spp., Cryptocline spp., Cryptosporium spp., and Melanophora spp.
A comparison of the soluble seed proteins of certain Acer species
Authors: Ziegenfus Theodore T. , Clarkson Roy B.
Published: September 2008

Seed proteins of seven taxa of Acer native to eastern North America were obtained by extraction in 2.5% saline buffer, pH 7.0. These were investigated using the techniques of polyacrylamide disc electrophoresis, immunoelectrophoresis, and double diffusion. Groupings indicated by our protein data were compared with groupings by other researchers based on morphological data. The members of the section Saccharina, A. saccharum subsp. saccharum, A. s. subsp. nigrum and A. s. subsp. floridanum, were found to have close protein similarity. A. negundo, thought by several workers to be the most distinct of the maples, was found to have relatively high protein similarity with the members of the section Saccharina. A. rubrum and A. spicatum were shown to have the least protein similarity to the other taxa investigated. There is low protein similarity between these two taxa, however, indicating they are divergent. The traditional placement of A. rubrum and A. saccharinum in the same section was supported by the relatively high protein similarity of these taxa. Data obtained by serological techniques and polyacrylamide disc electrophoresis were found to be complementary. However, polyacrylamide disc electrophoresis was more sensitive in detecting the protein differences among the taxa investigated.
Sporulation and pathogenicity of an Australian isolate of wheat rust grown in vitro
Authors: Bose A. , Shaw Michael
Published: September 2008

Colonies of Puccinia graminis Pers. f. sp. tritici Erikss. & Henn., race ANZ 126-6,7 were grown from uredospores on Czapek's mineral salts, 3% glucose, 0.1% Evans' peptone, plus defatted bovine serum albumen. Dikaryotic vegetative hyphae apparently developed from centers of germ tube anastomosis, without the formation of typical infection structures. Typical pigmented uredospores and teliospores were formed after 6 to 8 weeks growth. Both spore forms were coated with a layer of material which was visible under the scanning electron microscope and was not observed on uredospores grown on intact wheat leaves. The uredospores were capable of infecting the mesophyll of wheat leaves exposed by stripping back the lower epidermis. The possibility is considered that the surface coating of uredospores grown in vitro is related to their inability to infect intact leaves via the stomata.
Pigmentation in iris hybrids: the nature and development of flavonoid pigments and their effect on flower color in cultivated hybrids of Iris germanica
Authors: Ashtakala S. S. , Forward D. F.
Published: September 2008

The development of flavonoid pigments has been investigated in six cultivars of Iris germanica L. with a wide range of flower color but containing essentially the same pigments. Content and localization of anthocyanin and anthoxanthin pigments were observed throughout bud and flower development. All varieties, both cyanic and acyanic, showed a common pattern of initial development in early stages, with leucoanthocyanins preceding anthoxanthins, and anthocyanin appearing later. Pigment concentration reached a maximum in half-grown buds, and quantitative differences among varieties were established. Varieties with high anthocyanin content also had high anthoxanthin content. Relative concentrations of pigments rather than different chemical species appear to be a major factor in determining flower color.
Conditioning circadian rhythmic control of betacyanin content in Chenopodium rubrum by temperature and light intensity cycles during germination
Authors: Wagner Edgar , Frosch Silvia
Published: September 2008

Evidence is presented that a circadian rhythm in betacyanin accumulation in Chenopodium rubrum seedlings (ecotype 50°10′ N, 105°35′ W, selection 184) was initiated or synchronized by the cyclic temperature and light conditions that were imposed during germination. This rhythm was probably free-running in the constant light conditions that preceded the imposition of darkness. Rhythmic fluctuations in the time course of betacyanin content during darkness, which are probably due to betacyanin turnover, showed correlations with the alternating germination conditions, thus indicating that the rhythm is not initiated or rephased by the transition from light of 600 or 3000 ft-c to darkness. Light following darkness increased the respective level of betacyanin accumulation but did not alter the phasing of the rhythm as compared with darkness. The metabolic activity of the seedlings in the light, following darkness, depends on the specific phase of the endogenous rhythm at the time of the dark: light transition.
Verticillium wilt of chrysanthemum: suppression of fungal colonization of leaves and prevention of wilt symptom development by foliar applications of benomyl
Authors: Busch Lloyd V. , Hall Robert
Published: September 2008

This report describes the use of a systemic fungicide in a study of the relation between fungal colonization of a plant and symptom expression. The systemic fungicide benomyl (methyl 1-(butylcarbamoyl)-2-benzimidazolecarbamate) was used to selectively suppress development of Verticillium dahliae in leaves of chrysanthemum plants infected via the roots.Benomyl sprayed or painted onto foliage at weekly intervals as a 20 mg/liter solution in 0.25% aqueous Tween 20 restricted development of V. dahliae in leaves and prevented wilt symptom development. Numbers of propagules of V. dahliae recovered from stems of symptomless benomyl-treated plants were similar to those recovered from stems of untreated inoculated plants expressing wilt symptoms. Material toxic to Verticillium was detected in leaves but not in stems of plants receiving foliar paint applications of benomyl. Benomyl applied repeatedly to a single leaf on an inoculated plant suppressed fungal growth and symptom development in that leaf while untreated leaves wilted and became necrotic in the usual way. The observations support the hypothesis that symptom expression in leaves of chrysanthemum plants infected with Verticillium is largely due to fungal activity within infected leaves rather than fungal activity in the roots or stem.
Pathogenicity and developmental differences of three saprophytically growing isolates of the flax rust fungus Melampsora lini, race 3
Authors: Turel Franziska L. M.
Published: September 2008

Small mycelial cultures from four isolates of Melampsora lini (Pers.) Lév., subcultured on agar media for up to 1[Formula: see text] years, infected detached flax cotyledons in culture through the wounds. Uredospores formed after 4 to 10 weeks at 16 °C under fluorescent lighting for 8 to 16 h/24 h, especially on media containing 5% sucrose. These spores infected whole greenhouse plants and testing on differential hosts proved all isolates to belong to race 3. Persistent differences between isolates in mycelial and spore development are described.
Effects of prior environmental conditions on the subsequent uptake and release of carbon dioxide in the light
Authors: Steward F. C. , Craven G. H. , Weerasinghe S. P. R. , Bidwell R. G. S.
Published: September 2008

Rates of uptake and simultaneous evolution of carbon dioxide in the light were measured on leaves from various plants by a 14CO2–12CO2 technique under standardized conditions. The measurements were made on leaves from rice, potato, and carrot plants grown under conditions of long or short days combined with high or low night temperatures. The rates of uptake and release of carbon dioxide in the light, and the relationships between them, were affected by the prior conditions that obtained during growth (day length and night temperature), by the age of the leaves, and by the developmental stage of the plants. Since the total uptake of carbon dioxide and its release in the light did not always respond to these variables to the same extent, or even in the same direction, the effectiveness of photosynthesis was often markedly affected. The implications of these observations are, therefore, discussed.
Regenerative studies on the detached leaves of Echeveria elegans. Patterns of regeneration of leaves in sterile culture
Authors: Raju M. V. S. , Mann Henry E.
Published: September 2008

Entire detached leaves (L30 and older) and leaf-halves of Echeveria elegans Bgr. were cultured aseptically on an agar medium to study their regenerative capacity. The entire leaves with their bases intact produced shoots and roots regardless of whether they were placed erect, inverted, or flat on the medium. Similar leaves with their bases severed and placed erect produced roots from their cut ends. The proximal leaf-halves showed a regeneration pattern similar to the entire leaves depending on, of course, whether the leaf bases were cut or not. The regeneration in the distal halves was identical to the proximal halves whose bases had been removed. In the inverted position, a few distal halves and proximal halves with their bases removed produced shoots and roots. In all leaf types, inverted, erect, or flat, the regeneration occurred at the proximal end and in some exceptional cases, roots were formed at the distal cut end too. In general, the regeneration potential appeared to be much greater in the proximal parts than in the distal parts of detached leaves and the anatomy in the former was more favorable for regeneration than in the latter. Cutting the leaf base altered the regeneration pattern in the detached leaf but it did not have any effect on the capacity for regeneration to produce differentiated organs. The leaf fragments showed strict polarity in shoot formation which occurred only in the proximal region. The roots, on the other hand, appeared at proximal and distal ends.
Extracellular ribonuclease secretion by Ustilago hordei
Authors: Bech-Hansen N. T. , Person C. O.
Published: September 2008

RNase assays and gel electrophoresis of culture media have provided evidence that U. hordei, grown in vitro during the haploid (non-parasitic) phase, produced several extracellular RNases. The secretion of the RNases occurred during the end of log phase and at the beginning of stationary phase. Secretion was not affected by the addition of RNA, or by varying the inorganic phosphate concentration; it was enhanced in media of increased glucose content.
Ultrastructure and development of urediospore ornamentation in Melampsora lini
Authors: Littlefield L. J. , Bracker C. E.
Published: September 2008

The urediospores of Melampsora lini (Ehrenb.) Lev. are echinulate, with spines ca. 1 μ long over their surface. The spines are electron-transparent, conical projections, with their basal portion embedded in the electron-dense spore wall. The entire spore, including the spines, is covered by a wrinkled pellicle ca. 150–200 Å thick. The spore wall consists of three recognizable layers in addition to the pellicle. Spines form initially as small deposits at the inner surface of the spore wall adjacent to the plasma membrane. Endoplasmic reticulum occurs close to the plasma membrane in localized areas near the base of spines. During development, the spore wall thickens, and the spines increase in size. Centripetal growth of the wall encases the spines in the wall material. The spines progressively assume a more external position in the spore wall and finally reside at the outer surface of the wall. A mutant strain with finely verrucose spores was compared to the wild type. The warts on the surface of the mutant spores are rounded, electron-dense structures ca. 0.2–0.4 μ high, in contrast to spines of the wild type. Their initiation near the inner surface of the spore wall and their eventual placement on the outer surface of the spore are similar to that of spines. The wall is thinner in mutant spores than in wild-type spores.
Studies on the endogenous respiration of the psychrophilic fungus, Typhula idahoensis
Authors: Dejardin Rosamund A. , Ward E. W. B.
Published: September 2008

The effect of exogenous substrates on the endogenous respiration of intact mycelium of the snow mold fungus Typhula idahoensis Remsb. was studied by manometric and isotopic techniques. Endogenous respiration was stimulated by glucose at 5 °C and 20 °C and by acetate at 5 °C. Stimulation by glucose tended to be greater at 5 °C than 20 °C in unstarved and 24-h-starved medium. The extent of stimulation increased at both temperatures after longer periods of starvation.Glucose oxidation also increased after starvation, indicating that it was normally suppressed by high levels of endogenous reserves. Between 5 °C and 20 °C, exogenous respiration of glucose and acetate increased three- and four-fold respectively while endogenous respiration only doubled. Oxidative assimilation of glucose at 5 °C and 20 °C and acetate at 5 °C was extremely high; lower amounts of acetate were assimilated at 20 °C. Comparison of 14C distribution with and without the use of acid to terminate experiments indicated that considerable 14C material was released from the mycelium upon acidification.The results are discussed with relation to the possible existence of separate pools of endogenous reserves and the thermosensitivity of some aspects of endogenous metabolism.
Phenols and coumarins of tomato plants
Authors: Méndez J. , Brown Stewart A.
Published: September 2008

Vanillic and salicylic acids, and the coumarins marmesin, herniarin, esculetin, and bergapten were identified as constituents of whole tomato plants by paper and thin-layer chromatography and ultraviolet spectroscopy in the presence of diagnostic reagents. Strong evidence for the occurrence of p-hydroxybenzoic, syringic, ferulic, and p-hydroxycinnamic acids was obtained on the basis of chromatographic data and chromogenic reactions. Only the last two compounds and salicylic acid had been reported to occur in tomato plants. Biosynthetic implications of the occurrence of these phenolics are considered.
Changes in the phenolic metabolism of tomato plants infected by Agrobacterium tumefaciens
Authors: Méndez J. , Brown Stewart A.
Published: September 2008

Within 1 week after inoculation of young tomato plants with Agrobacterium tumefaciens marked qualitative differences from wounded controls were observed in the pattern of carboxylic acids liberated by acid hydrolysis of whole-plant extracts. Salicylic and gentisic acids were detected in the controls but not in the infected plants. In contrast, p-hydroxybenzoic acid and an unidentified acid giving a chromogenic reaction with diazotized sulfanilic acid were found only in the diseased plants. No qualitative differences persisted 2 weeks from inoculation, but beyond the first week salicylic and gentisic acids had not only appeared in the infected plants but the level of the latter considerably exceeded that in the controls. The syringic acid content of the diseased plants appeared to be higher throughout the 4-week duration of the experiment.
The major glycoprotein in germinating bean seeds
Authors: Racusen David , Foote Murray
Published: September 2008

Bean seeds (Phaseolus vulgaris) yielded a soluble glycoprotein that accounted for about 35% of the total protein as determined by combined analysis with DEAE-cellulose and disc electrophoresis. Germination for up to 114 h had little effect on this glycoprotein or on the total soluble protein. The glycoprotein had an apparent molecular weight of 130 000 (6.1 S), contained 14.7% nitrogen, and yielded mannose, glucosamine, and some pentose upon hydrolysis.
The effect of imbibition of solutions of aniline on germination, growth, and red pigmentation of seedlings
Authors: Nozzolillo Constance
Published: September 2008

Seeds of 10 species of dicotyledons were placed into varying concentrations of solutions of aniline (C6H5NH2) for 16 h. All three parameters studied, germination, growth, and pigmentation, were adversely affected in runner bean, Phaseolus coccineus; bush bean, P. vulgaris; mung bean, P. aureus; buckwheat, Fagopyrum esculentum; radish, Raphanus sativus; flax, Linum usitatissimum; eggplant, Solanum melongena; and tomato, Lycopersicon esculentum, by imbibition of a 0.05 M solution. By contrast, pigmentation in sweet basil, Ocimum Basilicum, and sensitive plant, Mimosa pudica, was enhanced. Competition by aniline in hydroxylase reactions and in sugar-requiring processes via a postulated glycosylation detoxication reaction is suggested as a possible mode of action.
On the identity of three species of Cylindrosporium described by Preuss
Authors: Raj T. R. Nag , Kendrick Bryce
Published: September 2008

A study of the presumed type specimens of Cylindrosporium crassipes Pr., Cylindrosporium inflatipes Pr., and Cylindrosporium longipes Pr. has shown that their transfer to Chalara by previous authors is justified. Chalara inflatipes (Pr.) Sacc. is an earlier name for Chalara insigne (Sacc., Rouss. & Bomm.) Hughes. A collection in B (Botanisches Museum, Berlin-Dahlem, Germany) as Chalara longipes forms the basis for a new species.
Daily germination of Cronartium comandrae aeciospores
Authors: Powell J. M.
Published: September 2008

Cronartium comandrae Pk. aeciospores were collected daily from individual cankers and pustules on Pinus contorta Dougl. var. latifolia Engelm. Germination was high for the initial 2 to 4 weeks, but much lower during the second half of the sporulation period. Most individual cankers and pustules showed similar trends in their daily spore germination. Germination and weather conditions had no consistent relationship. However, wet spores rapidly lost color and germinated poorly. Contamination from the associated microflora, especially Penicillium spp., Cladosporium spp., and bacteria, increased as the season progressed, and contributed to the reduced spore viability.
Effects of tritiated water on the metabolism and germination of jack pine seeds
Authors: Durzan D. J. , Mia A. J. , Wang B. S. P.
Published: September 2008

Tritium, imbibed as tritiated water, which evoked the germination of jack pine, was recovered from alcohol-soluble and insoluble components of seeds. At 12 h, tritium labeled nonexchangeably a few but not all free amino acids. By 96 h, all amino acids contained tritium but in seeds killed by heat no radioactive amino acids were detected. Radioactivity in glutamic acid, alanine, proline, and γ-aminobutyric acid implicated key roles for α-ketoacids and semialdehydes during germination. Two neutral fractions accounted for over 80% of the tritium in alcohol-soluble compounds.Levels of tritium above 1.0 mCi/ml water per gram dry seed inhibited water intake after 1 h and inactivated the germination of seeds by 96%. The total soluble N and amide content were also significantly reduced as alanine N increased. Specific activities of glutamine and γ-aminobutyric acid but not of all amino acids were proportional to tritium dose. Radioactivity in glutamine was not associated with the amide N supporting the specific labeling by tritium at the α-carbon of glutamic acid. At high levels of tritium radioactivity was concentrated in the insoluble (protein) fraction and was accompanied by brittleness of tissues and subcellular disruption. Tritium although localized mostly in the cytoplasm was more concentrated per unit area throughout chromatin regions of the nucleus than in the cytoplasm.