scholarly journals Effect of abiotic stresses on germination behaviour of Ruta chalepensis

Botanica ◽  
2021 ◽  
pp. 23-33
Author(s):  
Aounia Hamdini ◽  
Zoheir Mehdadi ◽  
Mohammed Dadach ◽  
Ali Latreche
Keyword(s):  
Polyethylene Glycol ◽  
Sodium Chloride ◽  
Germination Percentage ◽  
Annual Rainfall ◽  
Latency Time ◽  
Optimum Temperature ◽  
Ruta Chalepensis ◽  
Different Temperatures ◽  
Germination Behaviour ◽  
Velocity Coefficient

This work aims to highlight the optimal temperature for the seed germination of Ruta chalepensis, an important threatened ethnomedicinal shrub, and assess its germination tolerance against salinity and water stresses as well. For this, the seeds were incubated firstly under different temperatures (5 to 30°C). After that, at 20°C, germination tests were performed under different sodium chloride (NaCl) concentrations (0 to 273.9 mM) and various polyethylene glycol solutions (PEG6000) (0 to -2.20 bar). Final germination percentage, velocity coefficient and latency time were subsequently the germination patterns determined and analysed. The optimum temperature for germination was 15°C, in which the maximum final germination percentage (85%) was noticed; germination fell steadily, however, above and below this temperature and completely ceased at 30°C. Germination behaviour of R. chalepensis seeds under osmotic stress conditions showed a significant effect of both NaCl and PEG6000. Germination decreased whether sodium chloride or polyethylene glycol was increased in the medium (p < 0.05). Moreover, the salinity tolerance threshold was 205.4 mM, equivalent to 16 g L-1 NaCl, while water stress was -1.16 bar, corresponding to 80 g L-1 PEG6000. Beyond these thresholds, germination stopped. Dropping in velocity coefficient and postponing in latency time with increasing both stresses were recorded either. The sensitivity of R. chalepensis seeds to environmental stresses should be taken into account for successful conservation programmes, which should be implemented by sowing seeds and planting seedlings in fresh habitats with sufficient annual rainfall.

scholarly journals Germination behaviour of seeds from herbicide treated plants of Chenopodium album L.

2009 ◽  
Vol 81 (4) ◽  
pp. 873-879 ◽  
Author(s):  
Asif Tanveer ◽  
Muhammad A. Nadeem ◽  
Asghar Ali ◽  
Muhammad Tahir ◽  
Muhammad S.I. Zamir
Keyword(s):  
Allium Cepa ◽  
Low Temperatures ◽  
Chenopodium Album ◽  
Germination Percentage ◽  
Allium Porrum ◽  
Different Temperatures ◽  
Germination Behaviour ◽  
Carry Over ◽  
Germinated Seeds ◽  
Carry Over Effect

The carry-over effect of sub-lethal herbicides was investigated on the germination of seeds collected from surviving Chenopodium album plants, which had received 1/8, 1/8 twice, 1/8 three times, 1/4, 1/2, 1/1 doses of either pre-emergence ioxynil or post-emergence bentazone in a previous onion (Allium cepa) crop. Seeds were also collected from surviving C. album plants, which had received 1/4, 1/2, 1/1 of either pre-emergence pendimethalin, propachlor and linuron, or 1/8, 1/8 twice, 1/8 three times, 1/4, 1/2, 1/1 of post-emergence ioxynil or linuron in a previous leek (Allium porrum) crop. Seeds of surviving plants were collected and tested for germination at temperature of 5, 10, 15, 20 and 25°C. The effect of different temperatures on the total number of germinated seeds was significant. Germination was minimum at low temperatures (5°C or 10°C). Herbicides did not show any effect on germination of C. album and resulted in the same final germination percentage as seeds collected from the unsprayed control plots.

Development, Evaluation and Optimization of Osmotic Controlled Tablets of Aceclofenac for Rheumatoid Arthritis Management

2019 ◽  
Vol 9 (1) ◽  
pp. 29-36
Author(s):  
Bijaya Ghosh ◽  
Niraj Mishra ◽  
Preeta Bose ◽  
Moumita D. Kirtania
Keyword(s):  
Rheumatoid Arthritis ◽  
Polyethylene Glycol ◽  
Sodium Chloride ◽  
Cellulose Acetate ◽  
Hydroxypropyl Methylcellulose ◽  
Release Profile ◽  
Polyethylene Glycol 400 ◽  
Permeable Membrane ◽  
Cumulative Release ◽  
The Core

Objective: Rheumatoid arthritis is a dreaded disease, characterized by pain, inflammation and stiffness of joints, leading to severe immobility problems. The disease shows circadian variation and usually gets aggravated in early morning hours. Aceclofenac, a BCS Class II compound is routinely used in the treatment of pain and inflammation associated with rheumatoid arthritis. The objective of this study was to develop an osmotic delivery system of Aceclofenac that after administration at bedtime would deliver the drug in the morning hours. </P><P> Methods: A series of osmotically controlled systems of aceclofenac was developed by using lactose, sodium chloride and hydroxypropyl methylcellulose K100M as osmogens. Cellulose acetate (2% w/v in acetone) with varying concentrations of polyethylene glycol-400 was used as the coating polymer to create semi permeable membrane and dissolution was carried out in 290 mOsm phosphate buffer. Formulation optimization was done from four considerations: cumulative release at the end of 6 hours (lag time), cumulative release at the end of 7 hours (burst time), steady state release rate and completeness of drug release. </P><P> Results: A formulation having swelling polymer hydroxypropyl methylcellulose in the core and lactose and sodium chloride as osmogens, polyethylene glycol-400 (16.39 %) as pore former, with a coating weight of 5% was a close fit to the target release profile and was chosen as the optimum formulation. Conclusion: Aceclofenac tablets containing lactose, HPMC and sodium chloride in the core, given a coating of cellulose acetate and PEG-400 (5% wt gain), generated a release profile for optimum management of rheumatoid arthritic pain.

scholarly journals GERMINATION AND VIGOUR IN SEEDS OF THE COWPEA IN RESPONSE TO SALT AND HEAT STRESS

2019 ◽  
Vol 32 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Luma Rayane de Lima Nunes ◽  
Paloma Rayane Pinheiro ◽  
Charles Lobo Pinheiro ◽  
Kelly Andressa Peres Lima ◽  
Alek Sandro Dutra
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
High Temperature ◽  
Low Temperature ◽  
Vigna Unguiculata ◽  
Salt Concentration ◽  
Dry Weight ◽  
Germination Percentage ◽  
Different Types ◽  
Different Temperatures

ABSTRACT Salinity is prejudicial to plant development, causing different types of damage to species, or even between genotypes of the same species, with the effects being aggravated when combined with other types of stress, such as heat stress. The aim of this study was to evaluate the tolerance of cowpea genotypes (Vigna unguiculata L. Walp.) to salt stress at different temperatures. Seeds of the Pujante, Epace 10 and Marataoã genotypes were placed on paper rolls (Germitest®) moistened with different salt concentrations of 0.0 (control), 1.5, 3.0, 4.5 and 6.0 dS m-1, and placed in a germination chamber (BOD) at temperatures of 20, 25, 30 and 35°C. The experiment was conducted in a completely randomised design, in a 3 × 4 × 5 scheme of subdivided plots, with four replications per treatment. The variables under analysis were germination percentage, first germination count, shoot and root length, and total seedling dry weight. At temperatures of 30 and 35°C, increases in the salt concentration were more damaging to germination in the Epace 10 and Pujante genotypes, while for the Marataoã genotype, damage occurred at the temperature of 20°C. At 25°C, germination and vigour in the genotypes were higher, with the Pujante genotype proving to be more tolerant to salt stress, whereas Epace 10 and Marataoã were more tolerant to high temperatures. Germination in the cowpea genotypes was more sensitive to salt stress when subjected to heat stress caused by the low temperature of 20°C or high temperature of 35°C.

Temperature Effect on Seed Germination Performance of a Local Variety of Onion in Bangladesh

2021 ◽  
Vol 1 (01) ◽  
pp. 27-30
Author(s):  
IRANI KHATUN ◽  
RIYAD HOSSEN
Keyword(s):  
Seed Germination ◽  
Temperature Effect ◽  
Performance Test ◽  
Germination Rate ◽  
Germination Percentage ◽  
Optimum Range ◽  
Local Variety ◽  
Different Temperatures ◽  
Local Farmers

Seed germination performance test of Taherpuri onion (a local variety of onion) under six different temperatures (15, 20, 25, 30, 35 and 40°C) was the main goal of this experiment. Germination percentage (GP) was calculated at highest 60.25% at 25°C, and the highest germination rate 20.08 was observed in the same temperature condition. The lowest germination performance (13.25 % germi-nation and 3.32 seeds per day as germination rate) was found at 40°C temperature. Finally, the authors mentioned the temperature 20 to 30°C as optimum range, and suggested the temperature 25°C as best suited for obtaining highest results in case of both germination percentage and germination rate of these seeds. To produce maximum seedlings of the local variety of onion, the mentioned temperature should be followed by the local farmers.

scholarly journals Physical characterization of Rhipsalis (Cactaceae) fruits and seeds germination in different temperatures and light regimes

2016 ◽  
Vol 76 (2) ◽  
pp. 367-373 ◽  
Author(s):  
A. B. Lone ◽  
R. C. Colombo ◽  
B. L. G. Andrade ◽  
L. S. A. Takahashi ◽  
R. T. Faria
Keyword(s):  
Seed Germination ◽  
Germination Percentage ◽  
Light Regimes ◽  
Total Absence ◽  
Germination Characteristics ◽  
Different Temperatures ◽  
Medium Time ◽  
Seeds Germination

Abstract The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.

scholarly journals Predatory activity of Arthrobotrys oligospora and Duddingtonia flagrans on pre-parasitic larval stages of cyathostominae under different constant temperatures

2001 ◽  
Vol 31 (5) ◽  
pp. 839-842 ◽  
Author(s):  
Clóvis de Paula Santos ◽  
Terezinha Padilha ◽  
Maria de Lurdes de Azevedo Rodrigues
Keyword(s):  
Optimum Temperature ◽  
Duddingtonia Flagrans ◽  
Arthrobotrys Oligospora ◽  
Egg Development ◽  
Free Living ◽  
Predatory Activity ◽  
Larval Stages ◽  
Different Temperatures ◽  
Reduction Percentage

The effect of different temperatures on the predatory activity of Arthrobotrys oligospora and Duddingtonia flagrans on the free-living larval stages of cyathostomes were evaluated in an experiment where feces of horses containing the parasites’ eggs were treated with these fungi and incubated under different constant temperatures (10°C, 15°C, 20°C, 25°C and 30°C ). The results indicated that the optimum temperature for egg development was 25°C. At 10°C the number of L3 recovered was practically zero, and at 15°C and 20°C, the percentage of larvae recovered was less than 3% of the total number of eggs per gram of feces. When these cultures subsequently were incubated for an additional period of 14 days at 27°C, they allowed the development of L3. In all the cultures inoculated with fungi a significant reduction in the number of larvae was observed. When incubated at 25°C or 30°C, the fungi caused reductions above 90%, in the number of L3. The samples cultivated at 10°C, 15°C, 20°C, 25°C and 30°C, when incubated for an additional period of 14 days at 27°C the reduction percentage of larvae was above 90% for A. oligospora. However, the same did not occur for D. flagrans. Here a reduction percentage between 47.5% and 41.8% was recorded when the cultures were incubated at 10°C and 20°C, respectively. The two species of fungi tested showed to be efficient in reducing the number of L3 when mixed with equine feces and maintained at the same temperature for the development of larval pre-parasitic stages of cyathostomes.

scholarly journals GERMINAÇÃO DE SEMENTES DE Vochysia bifalcata EM DIFERENTES SUBSTRATOS E TEMPERATURAS

FLORESTA ◽  
2014 ◽  
Vol 44 (4) ◽  
pp. 669 ◽  
Author(s):  
Helena Cristina Rickli ◽  
Antonio Carlos Nogueira ◽  
Henrique Soares Koehler ◽  
Katia Christina Zuffellato-Ribas
Keyword(s):  
Rio De Janeiro ◽  
Germination Percentage ◽  
Minas Gerais ◽  
Sao Paulo ◽  
São Paulo ◽  
Santa Catarina ◽  
Blotting Paper ◽  
Dense Forest ◽  
Germination Speed ◽  
Different Temperatures

Guaricica (Vochysia bifalcata) é uma espécie arbórea nativa do Brasil, presente na vegetação secundária da Floresta Ombrófila Densa dos estados do Paraná, Santa Catarina, São Paulo, Rio de Janeiro e Minas Gerais, sendo de grande importância na regeneração de áreas degradadas e para fins madeireiros. Este estudo teve por objetivo avaliar os efeitos de diferentes temperaturas (20, 25 e 30 °C) e substratos (rolo de papel, papel mata-borrão e vermiculita) na germinação de sementes de Vochysia bifalcata, as quais foram mantidas em germinadores sob luz constante. Foram realizadas avaliações diárias até o 20° dia após a semeadura, analisando-se as seguintes variáveis porcentagem de germinação, índice de velocidade de germinação, tempo médio de germinação e índice de sincronização. A temperatura de 25 °C, nos substratos papel mata-borrão e vermiculita apresentaram a maior germinação (70 e 73%, respectivamente) e maior índice de velocidade de germinação, porém com menor sincronismo. Assim, para o teste de germinação de guaricica, é recomendado o uso dos substratos papel mata-borrão ou vermiculita na temperatura de 25 °C.Palavras-chave:  Vochysiaceae; guaricica; índice de sincronização; índice de velocidade de germinação. AbstractGermination of Vochysia bifalcata under different substrates and temperatures. Guaricica (Vochysia bifalcata) is a native Brazilian tree species, present in the secondary vegetation of the Ombrophilous Dense Forest in the States of Paraná, Santa Catarina, São Paulo, Rio de Janeiro, and Minas Gerais. It is of great importance in degraded areas regeneration and for timber production. This research aimed to evaluate the effects of different temperatures (20, 25 and 30 ºC) and substrates (paper roll, blotting paper and vermiculite) during the germination of Vochysia bifalcata seeds. We conducted germination tests inside germination chambers under constant illumination. Until the 20th day after the installation, daily evaluations analyzed the following variables: germination percentage, germination speed index, average germination time, and synchronization index. The temperature of 25 °C in blotting paper and vermiculite substrate presented the highest germination (70 and 73%, respectively) and highest germination speed index, but with less synchronism. Therefore, it recommends use of blotting paper and vermiculite as substrates in a temperature of 25 ºC for the Vochysia bifalcata germination test.Keywords: Vochysiaceae; guaricica; index synchronization; germination speed index

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