Genetic Determination of Erect and Prostrate Growth Habit in Five Shrubs From Windswept Headlands in the Sydney Region

1992 ◽  
Vol 40 (1) ◽  
pp. 1 ◽  
Author(s):  
TD Auld ◽  
DA Morrison
Keyword(s):  
Growth Habit ◽  
Morphological Characteristics ◽  
Genetic Determination ◽  
Specific Variation ◽  
Banksia Ericifolia ◽  
Growth Habits ◽  
Genetically Determined ◽  
Different Characteristics ◽  
Prostrate Growth

In the Sydney region, many plants from populations on windswept headlands have a more prostrate growth habit compared with plants from populations of the same species occurring away from the coast. To determine whether these different growth habits are genetically determined, plants from four populations of each of five species (Acacia rnyrtifolia, Acacia suaveolens, Banksia ericifolia, Casuarina distyla, Hakea teretifolia) were grown under uniform glasshouse conditions. Multivariate analyses of six morphological characteristics indicate that, for four of these species, the offspring are similar to their maternal parent; we thus conclude that the habit differences are genetically fixed in these populations. The same trend is apparent for <I.C. distyla , although significant variation occurs in the offspring. Univariate analyses indicate that different characteristics reflect the habit differences in different species. For conservation biology, the implications of this intra-specific variation are that attempts should be made to conserve viable populations of all genetically isolated taxa within a species.

scholarly journals Growth Habit Determination of Genotypes of African Bermudagrass

HortScience ◽  
2007 ◽  
Vol 42 (7) ◽  
pp. 1513-1516 ◽  
Author(s):  
Kevin E. Kenworthy ◽  
Dennis L. Martin ◽  
Charles M. Taliaferro
Keyword(s):  
Growth Habit ◽  
Leaf Angle ◽  
Angle Measurements ◽  
The Common ◽  
Cynodon Transvaalensis ◽  
Growth Habits ◽  
Common Bermudagrass ◽  
Prostrate Growth

Six African bermudagrass (Cynodon transvaalensis Burtt-Davy) genotypes, one common bermudagrass [C. dactylon (L.) Pers. var. dactylon] genotype, and ‘Tifway’ (C. dactylon × transvaalensis) hybrid bermudagrass were evaluated for shoot type, leaf angle, and shoot angle. Evaluations were conducted to determine if these measurements could be used to differentiate among upright, intermediate, and prostrate growth habits. Significant differences were found for all three techniques, but attempts to group plants together as having prostrate, intermediate, or upright growth habits was not possible. ‘Tifway’ was intermediate between the African bermudagrass genotypes and the common genotype for shoot type observations, but was more similar to upright-growing African bermudagrass for leaf angle and the more prostrate-growing common bermudagrass for shoot angle. Quantification of shoot type and leaf angle did not appear as useful as shoot angle measurements for screening germplasm to identify upright or prostrate growth habits in bermudagrass.

GENETICS AND METABOLISM

PEDIATRICS ◽  
1960 ◽  
Vol 25 (4) ◽  
pp. 565-571
Author(s):  
Barton Childs
Keyword(s):  
Mutant Gene ◽  
Human Populations ◽  
Affected Patient ◽  
Adrenal Hyperplasia ◽  
Genetic Determination ◽  
The Subject ◽  
Definition Of ◽  
Genetically Determined ◽  
Or Genes

IT IS the part of wisdom when about to give a dissertation which one hopes will at once instruct and entertain, to provide at the outset some definition of the subject matter. Genetics is the study of the heritable components of variation; the heritable factors which determine the range or extent of diversity. So, genetics is concerned with heritable differences and likenesses between individuals and between species. One emphasizes the differences because one can be certain of genetic determination of a particular characteristic only when it exists in a population in two or more alternative forms. It is the variants which catch the eye and hold the attention of the investigator, and which by their presence suggest more than one form of the gene or genes which determine that particular characteristic. I would like in what follows to present some examples of investigations of some aspects of genetics in human populations. ADRENAL HYPERPLASIA Several years ago Dr. Melvin Grumbach and I studied the genetics of adrenal hyperplasia, using as our material the patients of Dr. Lawson Wilkins. Since the disease occurs in more than one member of a sibship and since parents are unaffected, we suspected that it was genetically determined and that the affected patient possessed a double dose of a mutant gene; that is, the characteristic was recessive.

scholarly journals Genetic determination of migration strategies in large soaring birds: evidence from hybrid eagles

2018 ◽  
Vol 285 (1884) ◽  
pp. 20180855 ◽  
Author(s):  
Ülo Väli ◽  
Paweł Mirski ◽  
Urmas Sellis ◽  
Mindaugas Dagys ◽  
Grzegorz Maciorowski
Keyword(s):  
Bird Species ◽  
Migration Strategy ◽  
Genetic Determination ◽  
Timing Of Migration ◽  
Habitat Suitability Modelling ◽  
Migration Strategies ◽  
Soaring Birds ◽  
Genetically Determined ◽  
Migratory Movements

The relative contributions of genetic and social factors in shaping the living world are a crucial question in ecology. The annual migration of birds to their wintering grounds and back provides significant knowledge in this field of research. Migratory movements are predominantly genetically determined in passerine birds, while in large soaring birds, it is presumed that social (cultural) factors play the largest role. In this study, we show that genetic factors in soaring birds are more important than previously assumed. We used global positioning system (GPS)-telemetry to compare the autumn journeys and wintering ranges of two closely related large raptorial bird species, the greater spotted eagle Clanga clanga and the lesser spotted eagle Clanga pomarina , and hybrids between them. The timing of migration in hybrids was similar to that of one parental species, but the wintering distributions and home range sizes were similar to those of the other. Tracking data were supported by habitat suitability modelling, based on GPS fixes and ring recoveries. These results suggest a strong genetic influence on migration strategy via a trait-dependent dominance effect, although we cannot rule out the contribution of social interactions.

Yellow Foxtail(Setaria lutescens)Biotype Studies: Growth and Morphological Characteristics

Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 632-636 ◽  
Author(s):  
C. A. Schoner ◽  
R. F. Norris ◽  
W. Chilcote
Keyword(s):  
United States ◽  
Medicago Sativa ◽  
Growth Habit ◽  
Leaf Shape ◽  
Morphological Characteristics ◽  
Dry Weight ◽  
Field Conditions ◽  
Eastern United States ◽  
Prostrate Growth ◽  
Shape And Size

Seed of yellow foxtail(Setaria lutescens(Weigel) Hubb.) biotypes collected in Connecticut, Iowa, Massachusetts, Pennsylvania, and California were grown under field conditions at Davis and Woodland, California. Three biotypes collected in California alfalfa(Medicago sativaL.) fields all exhibited only a prostrate growth habit; the biotypes from the eastern United States all had an upright growth habit. The California biotypes were always glaucous; those collected in the east were not glaucous. Ratio of culm height to culm length were near unity for the eastern biotypes but averaged 1.5 to 1.7 for the California biotypes. Variations existed between biotypes in days from planting to heading, number of nodes per culm, leaf shape and size, and in final dry weight per plant.

Screening of Infectious Causes of Diarrhea and Genetic Determination of Diarrheagenic E. coli using Multiplex PCR in under 5 Years Children in Egypt

2020 ◽  
Vol EJMM29 (4) ◽  
pp. 27-34
Author(s):  
Yosra M. Hassan ◽  
Saha r M. Khairat ◽  
Nada N. Nawar ◽  
Maha M. Gaafar ◽  
Dina M Hassan ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Infectious Diarrhea ◽  
Genetic Determination ◽  
E Coli ◽  
Single Positive ◽  
Life Threatening ◽  
Stool Specimens ◽  
Genetically Determined ◽  
Microbiological Procedures

Background: Infectious diarrhea represents a life-threatening problem among children in developing countries. Objectives: This work aimed to study bacterial, viral and parasitic causes of acute diarrhea; with genetic determination of diarrheagenic E. coli (DEC) in <5 years children. Methodology: Stool specimens were collected from 206 diarrheal children. Bacterial agents were isolated and identified by standard microbiological procedures. Multiplex PCR was done for genetic determination of DEC subtypes. ELISA was used for detection of viral and parasitic agents. Results: Stool specimens with at least single positive enteropathogen accounted for 98.5% with bacterial, viral and parasitic rates of 98.5%, 42.7% and 25.2%, respectively. Isolated bacteria were DEC (98.5%); Campylobacter (14%), Shigella (3.8%) and Salmonella (1.4%). Rota and Noroviruses showed prevalence of 32.5% and 5.3%, respectively. Conclusion: Infectious diarrhea were mostly due to bacterial agents. DEC and Campylobacter were predominant. EAEC and EPEC were the most genetically determined DEC subtypes.

Bryozoan growth habits: Classification and analysis

1998 ◽  
Vol 72 (3) ◽  
pp. 418-436 ◽  
Author(s):  
Steven J. Hageman ◽  
Philip E. Bock ◽  
Yvonne Bone ◽  
Brian Mcgowran
Keyword(s):  
Environmental Conditions ◽  
Common Ground ◽  
Growth Form ◽  
Growth Habit ◽  
Morphological Characteristics ◽  
Growth Forms ◽  
Marine Fauna ◽  
Form Analysis ◽  
Growth Habits

Bryozoans are an important part of the benthic marine fauna in a wide variety of modern environments and are found in rock forming abundance in a number of settings throughout much of the Phanerozoic. Bryozoologists and nonspecialists have grouped taxa into colonial growth forms (e.g., erect fenestrates or encrusting sheets), both to simplify analyses and because correlations exist between some colony growth forms and the environmental conditions in which the organism lived. These correlations allow for the possibility of paleoenvironmental analyses based on skeletons alone. Existing bryozoan colonial growth form classifications do not, however, fully exploit the ecological information present in colony form.A new scheme is proposed here (Analytical Bryozoan Growth Habit Classification), which provides a list of colony-level morphological characteristics for bryozoan growth habits. This differs from previous approaches to bryozoan growth form analysis in that it is a classification of growth habit characteristics rather than a classification of morphological groups as such. The classification is based on eleven character classes, which describe the orientation of the colony and its occupation of, and placement in space. The overall colony shape is described based on the arrangement of modules in colonial growth. This classification provides a common ground for systematic comparison of character states among varied bryozoan growth habits. This approach allows for the evaluation of correlations among observed morphological character states and specific environmental conditions in which they develop. In addition, these growth habit characters can be used to recognize, characterize, evaluate, and apply more traditional growth form groups in broader studies.

Scanning Transmission Electron Microscopy of Polyethylene Crystals

1980 ◽  
Vol 38 ◽  
pp. 242-245
Author(s):  
F. Khoury ◽  
L. H. Bolz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallization Temperature ◽  
Scanning Transmission Electron Microscopy ◽  
Growth Habit ◽  
Lateral Growth ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Growth Habits

The lateral growth habits and non-planar conformations of polyethylene crystals grown from dilute solutions (<0.1% wt./vol.) are known to vary depending on the crystallization temperature.1-3 With the notable exception of a study by Keith2, most previous studies have been limited to crystals grown at <95°C. The trend in the change of the lateral growth habit of the crystals with increasing crystallization temperature (other factors remaining equal, i.e. polymer mol. wt. and concentration, solvent) is illustrated in Fig.l. The lateral growth faces in the lozenge shaped type of crystal (Fig.la) which is formed at lower temperatures are {110}. Crystals formed at higher temperatures exhibit 'truncated' profiles (Figs. lb,c) and are bound laterally by (110) and (200} growth faces. In addition, the shape of the latter crystals is all the more truncated (Fig.lc), and hence all the more elongated parallel to the b-axis, the higher the crystallization temperature.

Growth and Branching Responses of Portulaca grandiflora to Foliar Applications of Chemical Growth Regulators

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447c-447
Author(s):  
T.J. Banko ◽  
M.A. Stefani
Keyword(s):  
Growth Regulators ◽  
Growth Habit ◽  
Stem Elongation ◽  
Block Design ◽  
Shoot Elongation ◽  
Main Shoot ◽  
Randomized Complete Block Design ◽  
Portulaca Grandiflora ◽  
Prostrate Growth ◽  
Secondary Shoot

During container production of portulaca, growth of long, prostrate, sparsely branched stems makes handling of plants difficult, and reduces their commercial appeal. Growers prefer to minimize shoot elongation while increasing branching to provide a full, compact plant. The objectives of this study were to evaluate growth regulators for promotion of branching and inhibition of stem elongation. Container-grown plants ≈21 cm in diameter were treated with sprays of ProShear (benzylaminopurine) at 62.4, 125, and 250 ppm; Promalin (benzyaminopurine + gibberellins 4+7) at 125, 250, and 500 ppm; Atrimmec (dikegulac) at 250, 500, and 750 ppm; and Florel (ethephon) at 250, 500, and 750 ppm. These treatments were compared with untreated controls in a randomized complete-block design. Main shoot lengths were measured at 16, 31, and 51 days after treatment (DAT). Numbers of new shoot breaks were counted 16 DAT. The growth habit, that is, tendency to grow upright or prostrate, was also evaluated 16 DAT. The most-effective material for retarding primary shoot elongation and for stimulating secondary shoot development was ProShear. At 16 DAT, 250 ppm ProShear reduced shoot elongation by 25% compared to control plants. This treatment also increased the number of secondary shoot breaks by 143%. Promalin increased the number of new shoot breaks, but it also increased the lengths of all shoots. High rates of Florel and Promalin caused shoots to grow predominantly upright rather then prostrate. ProShear, however, caused more prostrate growth as rate increased.

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