Morphophysiological dormancy, germination, and cryopreservation in Aristolochia contorta seeds

2018 ◽  
Vol 151 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Nina M. Voronkova ◽  
Alla B. Kholina ◽  
Marina N. Koldaeva ◽  
Olga V. Nakonechnaya ◽  
Vitaliy A. Nechaev
Keyword(s):  
Liquid Nitrogen ◽  
Adaptive Strategies ◽  
Optimal Conditions ◽  
Deep Freezing ◽  
Morphophysiological Dormancy ◽  
Breaking Dormancy ◽  
Aristolochia Contorta ◽  
Germination Experiments ◽  
First Time ◽  
Aristolochia Species

Background and aims – Aristolochia contorta is a valuable medicinal plant, a relict of the Tertiary flora. Little is known about the germination biology of Aristolochia. The specific objectives of the present study were to (1) determine the type of dormancy in seeds of A. contorta, (2) describe the embryo development, and (3) explore the influence of deep freezing of the seeds in liquid nitrogen on their germinability.Methods – Seeds were germinated in Petri dishes in sand previously sterilised at high temperature; germination experiments were carried out at 27±2°C under natural light. All measurements of seeds and embryos were done using light microscopy (LM). For cryopreservation, fresh seeds were placed in aluminium foil bags, immersed into liquid nitrogen (-196°С), and stored for twelve months.Key results – The seeds of Aristolochia contorta have non-deep simple morphophysiological dormancy. A variety of embryo forms were revealed for Aristolochia species for the first time. Two cases of polyembryony were noted in A. contorta. The seeds of A. contorta are resistant to cryopreservation in liquid nitrogen.Conclusions – High variability in dormancy depth and the extended germination period of A. contorta seeds can be considered as adaptive strategies for survival in unfavourable conditions and renewal of germination under optimal conditions. Cryopreservation helped maintain the viability of A. contorta seeds but did not lead to the breaking of the dormancy; hence, for successful germination, it is necessary to use methods of breaking dormancy after freezing.

scholarly journals Study of the Cryopreservation Conditions for seed Materials of Chartolepis intermedia Boiss.

2021 ◽  
Vol 38 ◽  
pp. 00046
Author(s):  
Margarita Ishmuratova ◽  
Saltanat Tleukenova ◽  
Alibek Ramasanov ◽  
Elena Gavrilkova ◽  
Dmitrii Ageev
Keyword(s):  
Seed Germination ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Germination Rate ◽  
Plastic Container ◽  
In The Wild ◽  
First Time ◽  
Karaganda Region

For the first time, the depending of germination rate and energy of germination of Chartolepis intermedia seeds, collected in the wild of Karaganda region, from morphology of seeds and conditions of cryopreservation is investigated. The maximum results for viability are fixed for dark-colored average or large seeds. The best results are determined for variant of cryopreservation in plastic container with future defrosting at the room temperature. For the increasing parameters of seed germination we recommended to freeze Chartolepis intermedia seeds with using cryoprotector sucrose in concentration 20%. As the results of the study, we developed algorithm of cryopreservation of Chartolepis intermedia seeds in liquid nitrogen.

scholarly journals Density-dependent effect of allelopathy on germination and seedling emergence in two Ipomoea species

2019 ◽  
Vol 92 (1) ◽  
Author(s):  
Zoila Mercedes Aguilar-Franco ◽  
Alejandro Flores-Palacios ◽  
Alejandro Flores-Morales ◽  
Irene Perea-Arango ◽  
José de Jesús Arellano-García ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seedling Emergence ◽  
Single Species ◽  
Allelopathic Effect ◽  
Plant Interactions ◽  
Species Trials ◽  
Germination Experiments ◽  
Action Modes ◽  
First Time ◽  
Seed Extracts

Abstract Background Density in inter and intraspecific plant-plant interactions affects the action modes of allelopathy (autotoxicity, negative and positive allelopathy). Some seeds exude compounds that inhibit the germination of others. Ipomoea murucoides and I. pauciflora are sympatric tree species that form patches at the local scale where one or the other dominates, possibly due to allelopathy in the seeds. The objective of this study was to determine the possible density-dependence of the allelopathic effect among seeds of these species through the measure of seed germination and seedling emergence. Methods In both species, allelopathy was measured as: a) germination in mixed sowing of both species at different proportions, b) germination in single-species trials at different densities after adding seed extracts of both species, and c) seedling emergence in seed mixtures of both species sown at different proportions beneath canopies of the two Ipomoea species. Results Seed germination of I. murucoides was increased by the presence of I. pauciflora and diminished at higher densities of its own seeds; however, seed germination of I. pauciflora was not affected by the presence of I. murucoides seeds. The addition of extracts (either from conspecifics or congeneric) diminished the germination of both species and at higher seed densities the germination was lower. Seedling emergence did not depend on the species under which the seeds were sown nor on the density of the seeds. Conclusions The germination experiments evidenced positive allelopathy and/or autotoxicity, while there was no evidence of allelopathic effects in seedling emergence. The allelopathic activity is reported in the seeds of these species for the first time.

scholarly journals Agropopulations of Trifolium hybridum (Fabaceae) on the coal mining spoils in the forest-steppe of the Kuznetsk basin

2020 ◽  
Vol 24 ◽  
pp. 00080
Author(s):  
Natalia Sheremet ◽  
Tatyana Lamanova ◽  
Vladimir Doronkin
Keyword(s):  
Coal Mining ◽  
Growth And Development ◽  
West Siberia ◽  
Kuznetsk Basin ◽  
Forest Steppe ◽  
Optimal Conditions ◽  
Disturbed Areas ◽  
First Time ◽  
Open Coal ◽  
Zonal Soils

The agropopulations of Trifolium hybridum L. were studied in the agricultural phytocenoses established on the levelled coal mining spoils in the Kuzbas mining region (West Siberia, Russia). The clover was found to last in such agrophytocenoses for more than 20 years, whereas in agricultural phytocenoses on the zonal soils it lasted usually for 5-8 years. All studied communities were dominated by virginal and young generative plants. The optimal conditions for the clover growth and development in the disturbed areas were observed in the mixed (legumes and grasses) agrophytocenosis on the hydraulic dump. For the first time T. hybridum was found to be a species perspective for restoring vegetation cover in areas disturbed by open coal mining.

scholarly journals Dormancy in native fruit seeds of the Brazilian South Region

2021 ◽  
Vol 17 (3) ◽  
Author(s):  
Kelli Pirola ◽  
Américo Wagner Junior ◽  
Marcelo Dotto ◽  
Darcieli Aparecida Cassol ◽  
Jean Carlo Possenti ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Native Species ◽  
Fruit Trees ◽  
Germination Percentage ◽  
Hot Water ◽  
Morphophysiological Dormancy ◽  
Fruit Species ◽  
Breaking Dormancy ◽  
Technological University

The aim of the present study was to investigate whether seeds from six native fruit species ofthe South Brazilian regionhad any type of dormancy, as well as, to verify if they havephotoblastism. The work was carried out at the Plant Physiology Laboratoryofthe Federal Technological University of Paraná –Câmpus Dois Vizinhos, Paraná State, Brazil. The influence of photoperiod factors and techniques for overcoming dormancy were tested on the germination of Eugenia uniflora L.(Surinan cherry), Plinia peruviana(native jabuticaba), Plinia cauliflora(hybrid jabuticaba), Eugenia involucrataDC. (Rio Grande cherry), Myrcianthes pungens(guabiju) and Campomanesia guazumifolia(sete capoteiro). The seeds were exposed in a condition of total darkness or photoperiod of 24 hours, being the levels of one of factors tested. The techniques for breaking dormancy tested werethe immersion in gibberellic acid solution (200 mg L-1); stratification at 5°C for 30 days; immersion in water at room temperature for 24 hours; immersion in hot water (80°C) for five minutes; immersion in sulfuric acid solution (96%) for five minutes; and manual physical scarification with 120 grit sandpaper. The seeds were also tested without using any technique, making up the controlstreatments with or without light. The experimental design was completely randomized, in a 2 x 7 factorial scheme (luminosity x treatment for breaking dormancy), with four replications of 100 seeds. After 60 days, germination (%), percentage of accumulated germination, germination speed index and average germination time were analyzed. The seeds of most of the studied native species do not present dormancy or the effect of photoblastism, except for “sete capoteiro”seedswho are supposed to have morphophysiological dormancy, with negative photoblastism. The use of hot water or sulfuric acid in the seeds of native fruit trees is not recommended.

scholarly journals Modeling the Optimal Conditions for Improved Efficacy and Crosslink Depth of Photo-Initiated Polymerization

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 217 ◽  
Author(s):  
Jui-Teng Lin ◽  
Hsia-Wei Liu ◽  
Kuo-Ti Chen ◽  
Da-Chuan Cheng
Keyword(s):  
Light Intensity ◽  
Light Exposure ◽  
Spatial Average ◽  
Type I ◽  
Optimal Conditions ◽  
Action Process ◽  
Temporal Profiles ◽  
First Time ◽  
Concentration Diffusion

Optimal conditions for maximum efficacy of photoinitiated polymerization are theoretically presented. Analytic formulas are shown for the crosslink time, crosslink depth, and efficacy function. The roles of photoinitiator (PI) concentration, diffusion depth, and light intensity on the polymerization spatial and temporal profiles are presented for both uniform and non-uniform cases. For the type I mechanism, higher intensity may accelerate the polymer action process, but it suffers a lower steady-state efficacy. This may be overcome by a controlled re-supply of PI concentration during the light exposure. In challenging the conventional Beer–Lambert law (BLL), a generalized, time-dependent BLL (a Lin-law) is derived. This study, for the first time, presents analytic formulas for curing depth and crosslink time without the assumption of thin-film or spatial average. Various optimal conditions are developed for maximum efficacy based on a numerically-fit A-factor. Experimental data are analyzed for the role of PI concentration and light intensity on the gelation (crosslink) time and efficacy.

Natural bee honey and Conservation of drone semen in liquid nitrogen

2022 ◽  
pp. 17-22
Author(s):  
A. Gulov ◽  
A. Laskin
Keyword(s):  
Liquid Nitrogen ◽  
Honey Bees ◽  
Rock Type ◽  
Egg Yolk ◽  
Deep Freezing ◽  
Glass Capillaries ◽  
Fertilizing Ability ◽  
June July ◽  
Selection Of ◽  
Stimulation Of

Purpose: Conducting a honey diluent test for creeples of sperm of a drone honey bee.Materials and methods. The material for the research served a sperm of the milled drone drums of the "Prioksky" type of the Midway breed of bees. The selection of sperm was carried out in June-July 2020 g by the method of artificial stimulation of the turning of the endofalosha in half-armed drones aged 25-30 days. The rock type "Prioksky" of the middle Russian breed of bees. Before freezing, the sperm was stored in glass capillaries in the cooled state at 3 ° C for 2 months. The following composition of the diluent was tested - 10% honey, lactose, sucrose, egg yolk and dimethyl sulfoxide.Results. Studies have shown the viability of sperm at 64.0 ± 1.8% (41.5-83.7), and a total mobility of 2.2 ± 0.6% (0-11.5). To evaluate the fertilizing ability of sperm, carried out artificial insemination of 10 bee modules. In 4 seeded bees dykens, the presence of sperm in a seed-hearter with a concentration of sperm from 0.22-4.4 million / μl is revealed. In paired eggs of three other seeded matters, the presence of sperm and the complete absence of spermatozoa in the seed-receptionist are recorded.Conclusion. Tests of the honey diluent for deep freezing sperm of the drone honey bees in liquid nitrogen confirmed its cryophylactic properties.

Evaluation of Thermally Crosslinked Poly(Acrylic Acid-Co-Maleic Acid) (PAMA)/Poly(Vinyl Alcohol) (PVA) Microneedle Arrays

2019 ◽  
Vol 819 ◽  
pp. 45-50 ◽  
Author(s):  
Nway Nway Aung ◽  
Yin Yin Myat ◽  
Tanasait Ngawhirunpat ◽  
Theerasak Rojanarata ◽  
Prasopchai Patrojanasophon ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Maleic Acid ◽  
Vinyl Alcohol ◽  
Transdermal Drug Delivery ◽  
Poly Vinyl Alcohol ◽  
Optimal Conditions ◽  
Microneedle Arrays ◽  
First Time ◽  
Polymer Ratio ◽  
Poly Acrylic Acid

This study aimed to evaluate the optimal conditions for crosslinked of PAMA/PVA microneedle (MN) arrays. Poly (acrylic acid-co-maleic acid) (PAMA)/poly (vinyl alcohol) (PVA) MN arrays were fabricated for the first time using the micromolding technique. The PAMA/PVA MN arrays at the polymer ratio of 1:4 were sharp, homogenous and perfectly formed with an elegant appearance. The successfully crosslinking MN arrays were determined using FTIR and water insolubilization. The results showed that increasing the crosslinking temperature and time, the degree of crosslinking also improved, which results in a decline in water uptake. The optimal crosslinking condition for PAMA/PVA MN arrays was 130°C for 1 h. Moreover, the highest swelling was observed from crosslinked PAMA/PVA MN arrays at 90°C for 0.5 h. These studies suggest that the combination of PAMA and PVA for fabrication of MN arrays could have a great potential to develop both hydrogel and dissolving MN devices for transdermal drug delivery.

scholarly journals Pd-Catalyzed Cyclocarbonylation of Allylic Alcohol under Benign Conditions with Ionic Liquid as Stabilizer

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2093
Author(s):  
Nasrin Nemati ◽  
Reza Eslamloueyan ◽  
Amalie Modvig ◽  
Anders Riisager
Keyword(s):  
Ionic Liquid ◽  
Catalyst System ◽  
Allylic Alcohol ◽  
Allylic Alcohols ◽  
Optimal Conditions ◽  
Consecutive Reactions ◽  
Partial Pressures ◽  
Palladium Catalyzed ◽  
First Time ◽  
Time Of Reaction

Homogeneous palladium-catalyzed (Pd-catalyzed) cyclocarbonylation of unsaturated allylic alcohols and alkynols in the presence of hydrogen forms lactone products with important applications in the food, perfume, and polymer industry. In this work, the cyclocarbonylation of 2-methyl-3-buten-2-ol was studied for the first time using a very active Pd-DPEphos (bis[(2-diphenylphosphino)phenyl]ether) catalyst in the presence of the ionic liquid (IL) [BMIM]Cl (1-butyl-3-methylimidazolium chloride) in dichloromethane to selectively produce 4,4-dimethyl-γ-butyrolactone. The effect of different parameters such as temperature, gas partial pressures, time of reaction, substrate and ligand concentrations were investigated and found to provide optimal conditions for lactonization (95 °C, 28 bar (CO/H2/N2: 20/5/3)), 18 h, 0.1 M substrate, and 16 mol% DPEphos), which were significantly milder than previously reported systems for cyclocarbonylation. Importantly, the study further showed that presence of the IL in the reaction mixture provided stabilization of the catalyst system and prevented formation of Pd-black, which allowed reuse of the catalytic system in consecutive reactions after intermediate extraction of the lactone product.

scholarly journals Inventory and Distribution of Rock Glaciers in Northeastern Yakutia

Land ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 384
Author(s):  
Vasylii Lytkin
Keyword(s):  
Arid Regions ◽  
Remote Sensing Data ◽  
Field Studies ◽  
Optimal Conditions ◽  
North East ◽  
The North ◽  
Rock Glaciers ◽  
Detailed List ◽  
First Time ◽  
North And South

Rock glaciers are common forms of relief of the periglacial belt of many mountain structures in the world. They are potential sources of water in arid and semi-arid regions, and therefore their analysis is important in assessing water reserves. Mountain structures in the north-east of Yakutia have optimal conditions for the formation of rock glaciers, but they have not yet been studied in this regard. In this article, for the first time, we present a detailed list of rock glaciers in this region. Based on geoinformation mapping using remote sensing data and field studies within the Chersky, Verkhoyansk, Momsky and Suntar-Khayata ranges, 4503 rock glaciers with a total area of 224.6 km2 were discovered. They are located within absolute altitudes, from 503 to 2496 m. Their average minimum altitude was at 1456 m above sea level, and the maximum at 1527 m. Most of these formations are located on the sides of the trough valleys, and form extended sloping types of rock glaciers. An assessment of the exposure of the slopes where the rock glaciers are located showed that most of the rock glaciers are facing north and south.

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