FLOWER DEVELOPMENT IN THE LOWBUSH BLUEBERRY

1955 ◽  
Vol 33 (3) ◽  
pp. 251-258 ◽  
Author(s):  
Hugh P. Bell ◽  
Jane Burchill
Keyword(s):  
Flower Development ◽  
Subsequent Development ◽  
Late Winter ◽  
Reproductive Tissue ◽  
Active Growth ◽  
Polygonum Type ◽  
Lowbush Blueberry

In the lowbush blueberry, floret primordia appear during June. Floral parts appear in acropetal succession during July. Ontogenetically the carpels are at first appendicular and later receptacular. The epigynous floret, in miniature, is formed by the first of August. During this month, some reproductive tissue is differentiated in both ovary and stamens. The characteristic resting stage is assumed during the autumn. Mitosis was observed in material collected during January and by late winter a number of ovules had two adjacent archesporial cells, the outer one later becoming functional. Definite differentiation starts during March. Active growth, including the initiation of meiosis, becomes general during April. Meiosis is completed in the anthers during the first week of May and about a week later in the ovules. Subsequent development in the ovule is of the Polygonum type. The flower is mature by the last week in May.

Embryological studies in the compositae, I. Sporogenesis, Gametogenesis, and Embryogeny in Cotula australis (Less.) Hook. F

1962 ◽  
Vol 10 (1) ◽  
pp. 1 ◽  
Author(s):  
GL Davis
Keyword(s):  
Mother Cell ◽  
Megaspore Mother Cell ◽  
Embryo Sac ◽  
Subsequent Development ◽  
Pollen Grains ◽  
Archesporial Cell ◽  
Polygonum Type ◽  
Wall Formation ◽  
Chalazal Megaspore

Cotula australis has a discoid heterogamous capitulum in which the outermost three whorls of florets are female and naked. The bisexual disk florets are fully fertile and have a four-lobed corolla with four shortly epipetalous stamens. The anthers contain only two microsporangia. Wall formation and microsporogenesis are described and the pollen grains are shed at the three-celled condition. The ovule is teguinucellate and the hypodermal archesporial cell develops directly as the megaspore mother cell. Megasporogenesis is normal and the monosporio embryo sac develops from the chalazal megaspore. Breakdown of the nucellar epidermis takes place when the embryo sac is binucleate and its subsequent development follows the Polygonum type. The synergids extend deeply into the micropyle and one persists until late in embryogeny as a haustorium. The development of the embryo is of the Asterad type, and the endosperm is cellular. C. coronopifolia agrees with C. australis in the presence of only two microsporangia in each anther and the development of a synergid haustorium.

Nitrogenase activity associated with Zostera marina from a North Carolina estuary

1982 ◽  
Vol 28 (4) ◽  
pp. 448-451 ◽  
Author(s):  
Garriet W. Smith ◽  
Steven S. Hayasaka
Keyword(s):  
North Carolina ◽  
Zostera Marina ◽  
Nitrogenase Activity ◽  
Growth Period ◽  
Winter Period ◽  
Late Winter ◽  
Active Growth ◽  
North Carolina Estuary ◽  
Active Growth Period

Nitrogenase activity (at in situ temperatures) associated with Zostera marina reflected the active growth periods of this plant in North Carolina coastal waters. During the plants most active growth period (late winter – spring) nitrogenase activity was primarily rhizospheric (8.47 μmol nitrogen fixed∙m−2∙day−1), while during its fall – early winter period it was primarily phyllospheric (8.03 μmol nitrogen fixed∙m−2∙day−1). No nitrogenase activity was detected during the warmer summer months when the plant is dormant. Phyllospheric nitrogenase activity (possibly the result of epiphytic heterocystic blue-green bacteria) was highest when plants were incubated aerobically in the presence of light.

scholarly journals Enhancing Early Spring Microclimate to Increase Carbon Resources and Productivity in June-bearing Strawberry

2002 ◽  
Vol 127 (3) ◽  
pp. 415-422 ◽  
Author(s):  
Lori J. Bushway ◽  
Marvin P. Pritts
Keyword(s):  
Plant Development ◽  
Flower Development ◽  
Leaf Growth ◽  
Early Spring ◽  
Plant Performance ◽  
Starch Accumulation ◽  
Late Winter ◽  
Carbohydrate Reserves ◽  
Photosynthetic Rates ◽  
Growth Chambers

Effects of early spring cultural practices and microclimate manipulation on `Jewel' strawberry (Fragaria ×ananassa Duch.) plant development, carbohydrate reserves, and productivity were measured in the field and under simulated early spring conditions in growth chambers. With traditional winter straw mulching practices of the northeastern and midwestern United States, starch content of overwintering leaves, crowns, and roots in the field declined by 51%, 78% and 69%, respectively, during late winter and early spring. There was also a net loss in root biomass over winter and no new leaf growth before mid-April, suggesting that carbohydrate reserves could be limiting plant performance during the critical early growth and flowering phase in spring. In growth chambers, exposure to CO2 levels between 700 to 1000 mL·L-1 significantly increased photosynthetic rates of overwintering and spring leaves compared to ambient CO2 levels. Elevated CO2 in growth chambers also accelerated flower development, reduced depletion of starch reserves in roots, and increased starch accumulation in crowns. In the field, early removal of straw and application of spunbonded rowcover accelerated plant development, increased starch accumulation in the leaves, and increased photosynthetic rates of overwintering and spring leaves. Elevating the CO2 levels under rowcover further increased photosynthetic rates and advanced plant development and starch accumulation, but not significantly above rowcover alone. Carbohydrate losses later in the season during flower development were reduced when rowcover was applied in early spring. Total fruit yield was as much as 48% higher for plants under rowcover in early spring than those that had no cover and an additional 9% higher when CO2 was elevated. Yield improvements were attributed mostly to an increase in the number of marketable secondary and tertiary fruit than to an increase in mean fruit size. The economics of rowcover use is favorable if the material is reused. The added expense of CO2 gas and the resulting marginal gains would not make field CO2 enrichment an economically viable practice for strawberry growers using the method herein.

Inhibition of flower development in Chenopodium rubrum by a photosynthetic inhibitor

1971 ◽  
Vol 49 (12) ◽  
pp. 2233-2237 ◽  
Author(s):  
Ramma Sawhney ◽  
Bruce G. Cumming
Keyword(s):  
Ascorbic Acid ◽  
White Light ◽  
Flower Development ◽  
Detrimental Effect ◽  
Subsequent Development ◽  
Chenopodium Rubrum ◽  
Low Intensity ◽  
Dimethyl Urea ◽  
Floral Primordia ◽  
Inductive Period

Cumming 1969 has demonstrated that the short-day plant Chenopodium rubrum (60°47′ N) is induced to flower if inductive darkness is substituted by a relatively long exposure to a low intensity light of a low red/far-red ratio (light emitted by BCJ lamps). DCMU (3(3,4-dichlorophenyl)-1,1-dimethyl urea), a photosynthetic inhibitor, inhibited flowering if applied during this inductive BCJ light period.Our experiments show that ascorbic acid and dichlorophenol-indophenol (which have been used as reducing agents in photosynthesis by various workers) overcome the effect of DCMU on flowering. Sugars are also effective in overcoming the DCMU effect. This indicates that DCMU acts specifically on photosynthesis and that there are no side effects.In Cumming's experiments DCMU was supplied at the start of a BCJ inductive period and then washed off at the end of the BCJ period. However, there are indications that DCMU may persist in the plant for several days after the medium on which plants are growing has been thoroughly washed off. This raises the question whether the action of DCMU is on induction in BCJ light or on subsequent development in white light. By applying DCMU during the BCJ period and terminating its effect by ascorbic acid + dichlorophenol-indophenol or sugars at the time of transferring to white light, no inhibition of flowering was found. This suggests that inhibition of photosynthesis during the inductive BCJ light had no detrimental effect on flowering. The inhibition of flowering by DCMU might be a result of inadequate photosynthesis in white light for development of floral primordia.

Tolerance of Five Warm-Season Turfgrass Species to Flumioxazin

2014 ◽  
Vol 28 (2) ◽  
pp. 340-350 ◽  
Author(s):  
Thomas V. Reed ◽  
Patrick E. McCullough
Keyword(s):  
Weed Control ◽  
Warm Season ◽  
Late Winter ◽  
Active Growth ◽  
Seashore Paspalum ◽  
Annual Bluegrass ◽  
Initial Injury ◽  
Annual Weeds

Flumioxazin provides PRE and POST, annual weed control in dormant bermudagrass, but applications during active growth may be injurious. Flumioxazin could also provide an alternative chemistry for POST annual bluegrass control in other turfgrasses, but research is limited on tolerance levels. The objective of this research was to evaluate tolerance of five warm-season turfgrasses to flumioxazin applied at various rates and timings. Late-winter applications of flumioxazin at 0.21, 0.42, or 0.84 kg ai ha−1caused acceptable (< 20%) injury to bermudagrass, seashore paspalum, St. Augustinegrass, and zoysiagrass at 3, 6, and 9 wk after treatment (WAT) in both years. In 2012, late-winter applications to centipedegrass caused unacceptable injury at 6 WAT, but turf recovered to acceptable levels by 9 WAT at all rates. Applications made during active turfgrass growth caused unacceptable initial injury to all species. However, bermudagrass, seashore paspalum, St. Augustinegrass, and zoysiagrass recovered to < 20% injury by 9 WAT from all rates. In 2012, centipedegrass treated in midspring had 0, 24, and 74% injury from flumioxazin at 0.21, 0.42, and 0.84 kg ha−1, respectively, at 9 WAT. In 2013, midspring applications to centipedegrass caused 13, 48, and 71% injury from 0.21, 0.42, and 0.84 kg ha−1, respectively at 9 WAT. Overall, flumioxazin has the potential to control annual weeds in bermudagrass, seashore paspalum, St. Augustinegrass, and zoysiagrass with late-winter applications before greenup, but all turfgrasses may be excessively injured during active growth.

Micropatterning of Permalloy Films by Electron Lithography

1976 ◽  
Vol 34 ◽  
pp. 448-449
Author(s):  
J. K. Maurin
Keyword(s):  
Electron Beam ◽  
Subsequent Development ◽  
Electron Optical System ◽  
Microelectronic Device ◽  
Magnetic Bubble ◽  
Control Beam ◽  
Photosensitive Material ◽  
Direct Exposure ◽  
Electron Lithography ◽  
Scanning Electron

Conductor, resistor, and dielectric patterns of microelectronic device are usually defined by exposure of a photosensitive material through a mask onto the device with subsequent development of the photoresist and chemical removal of the undesired materials. Standard optical techniques are limited and electron lithography provides several important advantages, including the ability to expose features as small as 1,000 Å, and direct exposure on the wafer with no intermediate mask. This presentation is intended to report how electron lithography was used to define the permalloy patterns which are used to manipulate domains in magnetic bubble memory devices.The electron optical system used in our experiment as shown in Fig. 1 consisted of a high resolution scanning electron microscope, a computer, and a high precision motorized specimen stage. The computer is appropriately interfaced to address the electron beam, control beam exposure, and move the specimen stage.

MEDIA SOCIALIZATION OF PERSONALITY IN THE CONTEXT OF INMUTATION IN THE MASS MEDIA

2021 ◽  
pp. 104-109
Author(s):  
Chernysh O.O.
Keyword(s):  
Mass Media ◽  
Negative Impact ◽  
Effective Interaction ◽  
Individual Characteristics ◽  
Media Culture ◽  
Active Growth ◽  
Media Space ◽  
The Media ◽  
The Individual

The urgency of the researched problem is connected with the growing role of mass media in modern conditions leads to change of values and transformation of identity of the person. The active growth of the role of the media, their influence on the formation and development of personality leads to the concept of “media socialization” and immutation in the media. The aim of the study is to outline the possibilities of the process of media socialization in the context of immutation in the media. The methods of our research are: analysis of pedagogical, psychological, literature, synthesis, comparison, generalization. The article analyzes the views of domestic and foreign scientists on the problem of immutation in the media and the transformation of the information space. In the context of the mass nature of the immutation of society, the concept of “media socialization” becomes relevant, which is the basis for reducing the negative impact of the media on the individual.The author identifies the lack of a thorough study of the concept of “media socialization” in modern scientific thought. Thus, media socialization is associated with the transformation of traditional means of socialization, and is to assimilate and reproduce the social experience of mankind with the help of new media.The article analyzes the essence of the concepts “media space”, “mass media” and “immutation”. The influence of mass media on the formation and development of the modern personality is described in detail.The study concluded that it is necessary to form a media culture of the individual, to establish safe and effective interaction of young people with the modern media system, the formation of media awareness, media literacy and media competence in accordance with age and individual characteristics for successful media socialization. The role of state bodies in solving the problem of media socialization of the individual was also determined. It is determined that the process of formation of media culture in youth should take place at the level of traditional institutions of socialization of the individual.The author sees the prospect of further research in a detailed analysis and study of the potential of educational institutions as an institution and a means of counteracting the mass nature of the immutation of society.Key words: immutation, media socialization, mass media, media space, information.

Severe Head Injury linked to Subsequent Development of Malignant Brain Tumour within a Short Period- A Case Report

2018 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Head Injury ◽  
Brain Tumour ◽  
Severe Head Injury ◽  
Case Reports ◽  
Subsequent Development ◽  
Malignant Brain Tumour ◽  
Tumour Development ◽  
Short Period ◽  
The Brain

There have been a few case reports of head injury leading to brain tumour development in the same region as the brain injury. Here we report a case where the patient suffered a severe head injury with contusion. He recovered clinically with conservative management. Follow up Computed Tomography scan of the brain a month later showed complete resolution of the lesion. He subsequently developed malignant brain tumour in the same region as the original contusion within a very short period of 15 months. Head injury patients need close follow up especially when severe. The link between severity of head injury and malignant brain tumour development needs further evaluation. Role of anti-inflammatory agents for prevention of post traumatic brain tumours needs further exploration.

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