scholarly journals Inherited dimorphism in cleistogamous flower production in Portulaca oleracea: a comparison of 16 populations growing under different environmental conditions

2019 ◽  
Author(s):  
Tomoyo Furukawa ◽  
Tomoyuki Itagaki ◽  
Noriko Murakoshi ◽  
Satoki Sakai
Keyword(s):  
Environmental Conditions ◽  
Adaptive Strategy ◽  
Plant Size ◽  
Climatic Conditions ◽  
Portulaca Oleracea ◽  
Original Population ◽  
Flower Production ◽  
Temperature Conditions ◽  
Previous Hypothesis ◽  
Cleistogamous Flower

Abstract Background and Aims Cleistogamy is considered to be an adaptive strategy resulting in plasticity in CH and CL flower production depending on environmental conditions and plant size. The aim of this study was to investigate whether CH and CL flower production in Portulaca oleracea is genetically differentiated among populations in association with climatic conditions. Methods First, we conducted growth experiments with P. oleracea seedlings from 16 populations under two temperature conditions. Second, we sowed seeds originating from the parents in the first experiment and grew the resulting plants to investigate whether flower production is heritable and plants in the same population show the same pattern of flower production. Key Results Two types of plants that produced only CH or CL flowers (referred to as CH and CL plants, respectively) were mainly observed, and the growing temperature conditions did not affect flower production. The frequency of CL plants increased with a decrease in the mean temperature in the original population. CL plants tended to begin reproduction earlier than CH plants, and the probability that a CH plant would flower decreased under the low-growing temperature conditions. Thus, CL plants may have some advantages in unfavourable environments in which early reproduction is necessary due to a short growing season and/or CH flowers cannot open due to low temperatures. The progeny originating from CH and CL plants also produced only CH and CL flowers, respectively, suggesting that there is a genetic basis for the dimorphism in flower production in P. oleracea, represented by CH and CL plants. Conclusions In contrast to the previous hypothesis that the production of both CH and CL flowers would be plastic, the genotypes producing either CH or CL flowers occurred at different frequencies under varying climatic conditions.

scholarly journals Germination Ecology of Catchfly (Silene conoidea) Seeds of Different Colors

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
A. TANVEER ◽  
M.M. JAVAID ◽  
R.N. ABBAS ◽  
H.H. ALI ◽  
M.Q. NAZIR ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Environmental Conditions ◽  
Climatic Conditions ◽  
Burial Depth ◽  
Weed Species ◽  
Successful Management ◽  
Nacl Concentration ◽  
Seed Polymorphism ◽  
Emergence Percentage ◽  
Annual Herb

ABSTRACT Catchfly (Silene conoidea), an annual herb, is usually recognized as an emerging weed species in Eurasia and North America. The presence of somatic seed polymorphism might aid in the adaptation of this weed in different climatic conditions. We conducted laboratory and greenhouse experiments to study the seed polymorphism and influence of various environmental factors like temperature, salt stress, osmotic stress and burial depth on the germination and emergence characteristics of catchfly. Optimum germination of seeds of all colors was recorded at a temperature of 15 oC. Germination of catchfly seeds of all colors followed decreasing trend as NaCl concentration increased from 50 mM to 200 mM. Seed germination was maximum (87-96%) at 0 MPa but gradually decreased to 40% as osmotic stress increases up to -0.4 MPa and completely inhibited at 0.6 MPa of all seed colors. A slight increase (from 60 to 95%) in the germination of seeds of black and dark brown colors was observed when seeding depth increased from 0 to 2 cm but decreased when seeding depth increased from 2 to 4 cm in seeds of all colors. There was no emergence of catchfly at seeding depth of 6 cm or greater. Our results concluded that catchfly seeds have the potential to germinate and emerge in various environmental conditions, but germination/emergence percentage of seeds of all colors will be different in different environmental conditions. Soil amendments including deep ploughing may aid for the successful management of this weed in cultivated areas.

scholarly journals First report on cyanobacterial flora from Masirah Island, Sultanate of Oman

Algologia ◽  
2020 ◽  
Vol 30 (4) ◽  
pp. 440-451
Author(s):  
M. Shamina ◽  
Keyword(s):  
Environmental Conditions ◽  
Food Industry ◽  
Vital Role ◽  
Taxonomic Composition ◽  
Climatic Conditions ◽  
Taxonomic Classification ◽  
Biofuel Production ◽  
Sultanate Of Oman ◽  
First Report ◽  
First Time

Cyanobacteria are organisms which play a vital role in various molecular and biotechnological aspects in food industry, agriculture, pharmaceuticals, neutraceuticals, biofuel production, etc., it is necessary to understand its adaptability to various environmental conditions. Furthermore it is equally important to discover new cyanobacterial taxa and with it occasional changes in taxonomic classification, thus the author set out to study cyanobacteria in extreme climatic conditions of desert, where temperatures are mostly above 45 oC. The taxonomic composition of cyanobacteria of Masirah Island, Sultanate of Oman, was studied for the first time. The studied samples were collected during the period of 2017–2019. The ten samples belonged to two orders: Oscillatoriales Schaffner and Synechococcales L.Hoffmann, Komárek & J.Kastovsky. All of them were filamentous non-heterocyst forms. Three species belonged to the genus Leptolyngbya Anagn. & Komárek, the genera Oscillatoria Vaucher ex Gomont and Lyngbya C.Agardh ex Gomont were represented by two species each, while the genera Pseudanabena Lauterborn, Planktolyngbya Anagn. & Komárek and Geitlerinema (Anagn. & Komárek) Anagn. were one species.

scholarly journals Svalbard reindeer (Rangifer tarandus platyrhynchus) antler characteristics reflecting the local environmental conditions

2019 ◽  
Vol 46 (1) ◽  
pp. 16-23
Author(s):  
Jan Kavan ◽  
Veronika Anděrová
Keyword(s):  
Environmental Conditions ◽  
Rangifer Tarandus ◽  
Well Being ◽  
Climatic Conditions ◽  
High Mountain ◽  
Atmospheric Conditions ◽  
Individual Subject ◽  
Svalbard Reindeer ◽  
Invasive Method ◽  
Antler Size

AbstractA new non-invasive method based on picture analysis was used to estimate the conditions in Svalbard reindeer populations. The well-being of an individual subject is often expressed through visual indices. Two distinct reindeer populations were compared based on their antler parameters. Relative antler size and number of tines are variables supposed to reflect correspondingly the environmental conditions of sedentary populations within the growing season. The occurrence areas of two studied populations are distinctly isolated – separated with high mountain ridges, glaciers and fjords. The population in Petuniabukta occupies a sparsely vegetated region with harsh climatic conditions, whereas Skansbukta represents an area with continuous tundra vegetation cover, milder climatic conditions and, consequently, also a longer vegetation season. These environmental factors probably caused significant differences in the relative antler size and number of tines in the studied species. The Skansbukta population exhibited a larger relative antler size and higher number of tines than the population in Petuniabukta (both parameters differed significantly, p < 0.01). This difference reflects concisely the different environmental conditions of both locations. A comparison of Skansbukta population antler characteristics between years 2017 and 2018 did not reveal significant changes, most probably due to very similar atmospheric conditions in these two years (in terms of air temperature).

scholarly journals Peat decomposition – shaping factors, significance in environmental studies and methods of determination; a literature review

Geologos ◽  
2016 ◽  
Vol 22 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Danuta Drzymulska
Keyword(s):  
Chemical Composition ◽  
Literature Review ◽  
Ground Water ◽  
Environmental Conditions ◽  
Meteoric Water ◽  
Climatic Conditions ◽  
Review Of Literature ◽  
Forming Process ◽  
Physical And Chemical

Abstract A review of literature data on the degree of peat decomposition – an important parameter that yields data on environmental conditions during the peat-forming process, i.e., humidity of the mire surface, is presented. A decrease in the rate of peat decomposition indicates a rise of the ground water table. In the case of bogs, which receive exclusively atmospheric (meteoric) water, data on changes in the wetness of past mire surfaces could even be treated as data on past climates. Different factors shaping the process of peat decomposition are also discussed, such as humidity of the substratum and climatic conditions, as well as the chemical composition of peat-forming plants. Methods for the determination of the degree of peat decomposition are also outlined, maintaining the division into field and laboratory analyses. Among the latter are methods based on physical and chemical features of peat and microscopic methods. Comparisons of results obtained by different methods can occasionally be difficult, which may be ascribed to different experience of researchers or the chemically undefined nature of many analyses of humification.

Modern problems of regionalization of territories and human adaptation in regions with extreme natural and climatic conditions

2021 ◽  
Author(s):  
A.L. Maksimov
Keyword(s):  
Environmental Factors ◽  
Environmental Conditions ◽  
Allostatic Load ◽  
Climatic Conditions ◽  
Extreme Conditions ◽  
Human Adaptation ◽  
Nonspecific Resistance ◽  
Key Words Adaptation ◽  
High Level ◽  
Selection Of

The paper considers modern approaches to the zoning of territories and the selection of people for life in extreme environmental conditions, taking into account modern geopolitical challenges. It is shown that it is possible, based on the allostasis concept, to conduct not only the selection of persons with a high level of nonspecific resistance, but also to quantify the degree of extremity of environmental factors using the standard represpiration test. Key words: adaptation, extreme conditions, selection, hypoxia, cold, rerespiration, allostatic load.

scholarly journals Effects of life history stage and climatic conditions on fecal egg counts in plains zebras (Equus quagga) in the Serengeti National Park

2020 ◽  
Vol 119 (10) ◽  
pp. 3401-3413
Author(s):  
Peter A. Seeber ◽  
Tetiana A. Kuzmina ◽  
Alex D. Greenwood ◽  
Marion L. East
Keyword(s):  
Life History ◽  
Environmental Conditions ◽  
National Park ◽  
Climatic Conditions ◽  
Life History Stage ◽  
Gastrointestinal Parasite ◽  
Serengeti Ecosystem ◽  
Life History Stages ◽  
Lactating Females ◽  
Host Life

Abstract In wildlife, endoparasite burden can be affected by host life history stage, environmental conditions, host abundance, and parasite co-infections. We tested the effects of these factors on gastrointestinal parasite infection in plains zebras (Equus quagga) in the Serengeti ecosystem, Tanzania, using fecal egg counts of two nematode families (Strongylidae and Ascarididae) and the presence/absence of cestode (Anoplocephalidae) eggs. We predicted higher egg counts of Strongylidae and Ascarididae, and increased likelihood of Anoplocephalidae infection in individuals (1) during energetically costly life history stages when resource allocation to immune processes may decrease and in young zebras after weaning because of increased uptake of infective stages with forage, (2) when climatic conditions facilitate survival of infective stages, (3) when large zebra aggregations increase forage contamination with infective stages, and (4) in individuals co-infected with more than one parasite group as this may indicate reduced immune competence. Strongylidae egg counts were higher, and the occurrence of Anoplocephalidae eggs was more likely in bachelors than in band stallions, whereas Ascarididae egg counts were higher in band stallions. Strongylidae and Ascarididae egg counts were not increased in lactating females. Strongylidae egg counts were higher in subadults than in foals. Regardless of sex and age, Ascarididae infections were more likely under wet conditions. Co-infections did not affect Strongylidae egg counts. Ascarididae egg counts in adult females were higher when individuals were co-infected with Anoplocephalidae. We present evidence that parasite burdens in plains zebras are affected by life history stage, environmental conditions, and co-infection.

Methodologies for Evaluating and Qualifying External Pipeline Coatings for Northern Pipelines

2006 ◽  
Author(s):  
S. Papavinasam ◽  
A. Doiron ◽  
T. Panneerselvam ◽  
Y. Lafrenie`re ◽  
M. Attard ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Low Temperatures ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Climatic Conditions ◽  
Limited Data ◽  
The North

The design of coatings must be adequate to protect pipelines under long-term, severe environmental conditions, including the extreme climatic conditions that will apply in the North before the pipe is installed and operation begins. Practices and standardised methodologies for evaluating and qualifying pipeline coatings for application in northern pipelines are discussed. Results from laboratory and field experiments, carried out under the conditions to which coatings will be exposed during construction, are presented. Based on 1-year laboratory experiments in which samples were exposed to temperatures as low as −45°C and limited data from the field experiments, it is concluded that Canadian Standards Association (CSA) standards CSA Z662, CSA Z245.20 and CSA Z245.21 adequately cover evaluation of coatings for northern pipelines. However, in order to evaluate the effects of low-temperatures, the specimens should be exposed for at least 4 months. Coatings qualified by CSA Z245.21 (System B1 and B2) are less affected from exposure to low-temperatures than those qualified by CSA Z245.21 (System A1) and CSA Z245.20.

Neoseiulus baraki (Acari: Phytoseiidae) survival and walking in response to environmental stress

2019 ◽  
Vol 24 (3) ◽  
pp. 487 ◽  
Author(s):  
Vaneska Barbosa Monteiro ◽  
Girleide Vieira França ◽  
Manoel Guedes Correa Gondim Jr ◽  
Debora Barbosa Lima ◽  
Jose Wagner Silva Melo
Keyword(s):  
Relative Humidity ◽  
Environmental Stress ◽  
Survival Time ◽  
Environmental Conditions ◽  
Walking Speed ◽  
Tracking System ◽  
Climatic Conditions ◽  
Stress Factors ◽  
Neoseiulus Baraki ◽  
Increasing Temperature

Living organism is exposed to the influence of various environmental conditions. These environmental conditions can trigger stress and compromise the fitness of the organism. As living organisms, phytoseiid mites are frequently exposed to a range of environmental stressors. In the present study, we attempted to explore the responses of the Neoseiulus baraki to environmental stress factors (temperature and humidity). Initially, the effect of different temperature (18–33 °C) and relative humidity (10–95%) levels on the survivorship of unfed N. baraki females was evaluated. Next, we estimated the walking parameters (distance traveled and average walking speed) with a computerized tracking system and we tested how N. baraki is constrained in their effective displacement by their ability to walk and survive in absence of food. The proportion of surviving N. baraki as well as mean survival time decreased significantly with increasing temperature. The opposite trend was observed to relative humidity. The distance covered by N. baraki reduced with increasing temperature (when only taking the temperature dependence of the survival time but not of walking speed and neither the tortuosity of the walking path) ranged from 550 m at 18 ºC to 100 m at 33 ºC. Under climatic conditions representative for the Tropics (27 ºC and 75 % RH) N. baraki was able to survive up to 1.5 days (36 h) without feeding and covered 0.9 m in 10 min as displacement estimated by walking.

scholarly journals Morpho-anatomical features of underground systems in six Asteraceae species from the Brazilian Cerrado

2011 ◽  
Vol 83 (3) ◽  
pp. 981-992 ◽  
Author(s):  
Beatriz Appezzato-da-Glória ◽  
Graziela Cury
Keyword(s):  
Environmental Conditions ◽  
Lateral Roots ◽  
Adaptive Strategy ◽  
Herbaceous Species ◽  
Bud Bank ◽  
Brazilian Cerrado ◽  
Neotropical Savanna ◽  
Anatomical Features ◽  
Paulo State ◽  
Vegetation Regeneration

In the Brazilian Cerrado (neotropical savanna), the development of bud-bearing underground systems as adaptive structures to fire and dry periods can comprise an important source of buds for this ecosystem, as already demonstrated in the Brazilian Campos grasslands and North American prairies. Asteraceae species from both woody and herbaceous strata have subterranean organs that accumulate carbohydrates, reinforcing the adaptive strategy of these plants to different environmental conditions. This study aims to analyse the morpho-anatomy of underground systems of six species of Asteraceae (Mikania cordifolia L.f. Willd., Mikania sessilifolia DC, Trixis nobilis (Vell.) Katinas, Pterocaulon alopecuroides (Lam.) DC., Vernonia elegans Gardner and Vernonia megapotamica Spreng.), to describe these structures and to verify the occurrence and origin of shoot buds, and to analyse the presence of reserve substances. Individuals sampled in Cerrado areas in São Paulo State showed thick underground bud-bearing organs, with adventitious or lateral roots and presence of fructans. Xylopodium was found in all studied species, except for Trixis nobilis, which had stem tuber. The presence of fructans as reserve, and the capacity of structures in the formation of buds indicate the potential of herbaceous species of Asteraceae in forming a viable bud bank for vegetation regeneration in the Brazilian Cerrado.

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