scholarly journals Discontinuous hydration alters seed germination under stress of two populations of cactus that occur in different ecosystems in Northeast Brazil

2017 ◽  
Vol 27 (4) ◽  
pp. 292-302 ◽  
Author(s):  
Ayslan T. Lima ◽  
Marcos V. Meiado
Keyword(s):  
Seed Germination ◽  
Stress Responses ◽  
Environmental Stresses ◽  
Arid Ecosystems ◽  
Saline Stress ◽  
Mean Germination Time ◽  
The Mean ◽  
Two Populations ◽  
Hydration And Dehydration ◽  
Water And Saline Stress

AbstractThe water uptake by the seed in arid and semi-arid ecosystems may not be continuous, but may occur in hydration and dehydration cycles (HD). In order to investigate the benefits of discontinuous hydration on seed germination of Pilosocereus catingicola subsp. salvadorensis subjected to environmental stresses, an imbibition curve was determined and times X, Y and Z selected, corresponding to 25, 50 and 75% of the first phase of imbibition, respectively. Seeds of two populations (Caatinga and Restinga) were subjected to 0, 1, 2 and 3 HD cycles, with 48 h of dehydration. Water and saline stress responses were tested at five osmotic potentials (0.0, –0.1, –0.3, –0.6 and –0.9 MPa). Discontinuous hydration provided greater tolerance to water and saline stress in the seeds from the Caatinga region. When the seeds were subjected to water stress, the reduction of the mean germination time (MGT) provided by HD cycles decreased with increasing concentration of the solution. In saline stress, the reduction of MGT was greater in the solutions with the highest concentrations. We conclude that the seeds of the same species collected from populations located in different ecosystems have different germination responses after passage through discontinuous hydration and HD cycles. This provides greater tolerance to environmental stresses but with different responses among populations.

scholarly journals Does discontinuous hydration of Senna spectabilis (DC.) H.S. Irwin & Barneby var. excelsa (Schrad.) H.S. Irwin & Barneby (Fabaceae) seeds confer tolerance to water stress during seed germination?

2018 ◽  
Vol 40 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Ayslan Trindade Lima ◽  
Paulo Henrique de Jesus da Cunha ◽  
Bárbara França Dantas ◽  
Marcos Vinicius Meiado
Keyword(s):  
Water Stress ◽  
Seed Germination ◽  
Stress Conditions ◽  
Hydration Time ◽  
Senna Spectabilis ◽  
Mean Germination Time ◽  
Polyethylene Glycol 6000 ◽  
Osmotic Potentials ◽  
Germination Parameters ◽  
Hydration And Dehydration

Abstract: Seed hydration memory is the ability of seeds to retain biochemical and physiological changes caused by discontinuous hydration. This study aimed to determine if Senna spectabilis (DC.) H.S. Irwin & Barneby var. excelsa (Schrad.) H.S.Irwin & Barneby (Fabaceae) present seed memory and evaluate the effects of hydration and dehydration cycles (HD) on the seed germination of this species when submitted to conditions of water stress. Seeds underwent HD cycles (0, 1, 2 and 3 cycles) corresponding to the hydration times X (6 hours), Y (16 hours) and Z (24 hours), determined from the imbibition curve, with 5 hours of dehydration and submitted to water stress conditions. Germination was evaluated at 0.0, -0.1, -0.3, -0.6 and -0.9 MPa, obtained with polyethylene glycol 6000 solution. Germinability (%), mean germination time (days) and hydrotime (MPa d-1) were calculated. The seeds of S. spectabilis var. excelsa are sensitive to the low osmotic potentials tested in this study, however, when submitted to the HD cycles of 16 hours hydration (time Y), the tolerance to water stress conditions is increased. In addition, the observed benefits on the evaluated germination parameters show that S. spectabilis var. excelsa present seed hydation memory.

scholarly journals Qualitative and Quantitative Evaluation Protocol of Baccharis Seed Germination

2019 ◽  
Vol 11 (3) ◽  
pp. 421 ◽  
Author(s):  
María Alejandra Moreno-Pizani ◽  
Asdrubal Jesus Farias-Ramirez ◽  
Hugo Thaner dos Santos ◽  
Ana Dionisia da Luz Coelho Novembre ◽  
Lorena Isabel Guevara-Orozco ◽  
...  
Keyword(s):  
Experimental Data ◽  
Seed Germination ◽  
Curve Fitting ◽  
Growth Pattern ◽  
Quantitative Information ◽  
Qualitative And Quantitative ◽  
Evaluation Protocol ◽  
Mean Germination Time ◽  
The Mean ◽  
Baccharis Trimera

Baccharis trimera (Less.) DC (E1) and Baccharis crispa Spreng. (E2) possess potential antimicrobial and anti-inflammatory properties. Qualitative and quantitative information on seed germination on these species is scarce. The objective of this investigation was to establish a protocol for evaluating seed germination of E1 and E2 and to analice the scoring and curve fitting by the Germinator package, for different periods of germination were between 0.93 and 0.99. Both species showed differences in germinability and mean germination time, 27 days for E1 and 20 days for E2. The germination dispersion showed that E1 germination was homogeneous, with differences in growth pattern, whereas the results on germination of E2. The mean speed of germination determined with the experimental data was close to the values obtained by the Germinator package, with a maximum germination of more than 34%, proving that the software was efficient for evaluating germination.

scholarly journals Effect of pre-sowing treatment on seed germination and seedling vigour in endive and chicory

2009 ◽  
Vol 36 (No. 3) ◽  
pp. 117-125 ◽  
Author(s):  
G. Tzortzakis N
Keyword(s):  
Seed Germination ◽  
Essential Oil ◽  
Plant Growth ◽  
Seedling Emergence ◽  
Fresh Weight ◽  
Seedling Vigour ◽  
Gibberelic Acid ◽  
Mean Germination Time ◽  
The Mean

The influence of pre-sowing treatments using hydropriming, osmopriming and halopriming in laboratory and/or nursery tests on seedling emergence, seedling weight and plant growth of endive and chicory was examined. Halopriming (KNO<sub>3</sub>) or growth regulators (gibberelic acid; GA<sub>3</sub>) improved the rate of germination of endive and chicory and reduced the mean germination time needed. 30 min pre-sowing treatment with NaHClO<sub>3</sub>, methyl jasmonate and dictamus essential oil decreased seed germination as well as seed radicle length in vitro. In the nursery tests, pre-sowing treatments had in some extent impact on the upper part (fresh weight) of the seedling, while no major changes were observed for leaf number and root fresh weight. 6-benzylaminopurine (BAP) or NaHClO<sub>3</sub> treatment reduced plant growth of both species. The present study suggests that KNO<sub>3</sub> and secondly GA<sub>3</sub> treatments may improve rapid and uniform seedling emergence and plant development in nurseries and/or in greenhouses, which is easily applicable by nursery workers with economic profits.

scholarly journals Application of Silica Nanoparticles Induces Seed Germination and Growth of Cucumber (Cucumis sativus)

2019 ◽  
Vol 28 (1) ◽  
pp. 57-68
Author(s):  
H. El-Ramady H. El-Ramady
Keyword(s):  
Seed Germination ◽  
Cucumis Sativus ◽  
Dry Weight ◽  
Nano Silica ◽  
Vigor Index ◽  
Germination Speed ◽  
Mean Germination Time ◽  
The Mean ◽  
Growth Development ◽  
Germination And Growth

Five rates of nano-silica (NS) suspensions (0, 100, 200, 300 and 400 mg L-1) were used to study their effects on seed germination and growth development of cucumber (Cucumis sativus). The rate of 200 mg L-1 significantly increased final germination%, germination speed, vigor index, and germination index by 28.7, 70.3, 46.7 and 68.8 %, respectively, compared to untreated seeds. However, it reduced the mean germination time by 31.7%. Similarly, 200 mg L-1 NS had the highest fresh and dry weight of germinant. However, all NS treatments enhanced the seed germination and growth development in comparison to control.

scholarly journals Seed germination of three endangered subspecies of Discocactus Pfeiff. (Cactaceae) in response to environmental factors

2018 ◽  
Vol 40 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Joana Paula Bispo Nascimento ◽  
Marcos Vinicius Meiado ◽  
José Alves Siqueira-Filho
Keyword(s):  
Seed Germination ◽  
Water Availability ◽  
Abiotic Factors ◽  
Saline Stress ◽  
Optimum Temperature ◽  
Light Conditions ◽  
Continuous Darkness ◽  
Germination Process ◽  
Osmotic Potentials ◽  
Water And Saline Stress

Abstract: Temperature, light, water availability and excessive salt in the soil are among the abiotic factors that most influence the germination process in semiarid ecosystems. The aim of the present study was to determine the effect of these abiotic factors on seed germination in three subspecies of cactus: Discocactus bahiensis, D. zehntneri subsp. petr-halfarii and D. zehntneri subsp. zehntneri. Seeds were set for germination under two light conditions (12-h light/dark photoperiod and continuous darkness) and 10 temperature treatments [eight constant temperatures (10, 15, 20, 25, 30, 35, 40 and 45 °C) and two alternating temperatures (30 to 20 °C and 35 to 25 °C)]. Polyethylene Glycol (PEG) 6000 and sodium chloride (NaCl) were used to simulate water and saline stress, respectively, with the following osmotic potentials: 0.0, -0.2, -0.4, -0.6, -0.8 and -1.0 MPa. Three subspecies were positive photoblastic. The optimum temperature for germination was 25 to 35 ºC for D. bahiensis and D. zehntneri subsp. zehntneri, and 30 to 35 ºC for D. zehntneri subsp. petr-halfarii. The seeds of all three subspecies exhibited tolerance to water and saline stress, as germination was observed at potentials for up to -0.6 MPa in the PEG and NaCl solutions.

Germination and initial growth of triticale seeds under stationary magnetic fields

2014 ◽  
Vol 2 (2) ◽  
pp. 72-79 ◽  
Author(s):  
Mercedes Florez ◽  
Elvira Martinez ◽  
Victoria Carbonell
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Seed Vigor ◽  
Initial Growth ◽  
Practical Application ◽  
Biochemical Processes ◽  
Mean Germination Time ◽  
Nutrition Value ◽  
The Mean ◽  
Growth Of Seedlings

The main objective of this study is to determine the effects of 125 mT and 250mT magnetic treatment on the germination and initial growth of triticale seeds. This objective has a practical application in agriculture science: early growth of triticale. An increase in the percentage and rate of germination of seeds and a stimulation of growth of seedlings as positive response to magnetic field treatment in rice, wheat, maize and barley seeds have been found in previous studies. Germination tests were carried out under laboratory conditions by exposing triticale seeds to magnetic field for different times. The effect was studied by exposure of seeds prior sowing. The mean germination time were reduced for all the magnetic treatments applied. Most significant differences were obtained for time of exposure of 1 and 24 hours and maximum reductions was 12%. Furthermore, seedlings from magnetically treated seeds grew taller than control. The longest mean total length was obtained from seedlings exposed to 125 and 250 mT for 24 hours. External magnetic fields are assumed to enhance seed vigor by influencing the biochemical processes by stimulating activity of proteins and enzymes. Numerous studies suggested that magnetic field increases ions uptake and consequently improves nutrition value.

Alleviation of dormancy in annual ryegrass (Lolium rigidum) seeds by hydration and after-ripening

Weed Science ◽  
2004 ◽  
Vol 52 (6) ◽  
pp. 968-975 ◽  
Author(s):  
Robert S. Gallagher ◽  
Kathryn J. Steadman ◽  
Andrew D. Crawford
Keyword(s):  
Seed Germination ◽  
Relative Humidity ◽  
Germination Rate ◽  
Dormancy Release ◽  
Annual Ryegrass ◽  
Dormant Seed ◽  
Lolium Rigidum ◽  
Time Model ◽  
Treatment Regimens ◽  
Two Populations

The effect of hydration (priming) treatment on dormancy release in annual ryegrass seeds from two populations was investigated. Hydration duration, number, and timing with respect to after-ripening were compared in an experiment involving 15 treatment regimens for 12 wk. Seeds were hydrated at 100% relative humidity for 0, 2, or 10 d at Weeks 1, 6, or 12 of after-ripening. Dormancy status was assessed after each hydration treatment by measuring seed germination at 12-hourly alternating 25/15 C (light/dark) periods using seeds directly from the hydration treatment and seeds subjected to 4 d postpriming desiccation. Seeds exposed to one or more hydration events during the 12 wk were less dormant than seeds that remained dry throughout after-ripening. The longer hydration of 10 d promoted greater dormancy loss than either a 2-d hydration or no hydration. For the seed lot that was most dormant at the start of the experiment, two or three rather than one hydration event or a hydration event earlier rather than later during after-ripening promoted greater dormancy release. These effects were not significant for the less-dormant seed lot. For both seed lots, the effect of a single hydration for 2 d at Week 1 or 6 of after-ripening was not manifested until the test at Week 12 of the experiment, suggesting that the hydration events alter the rate of dormancy release during subsequent after-ripening. A hydrothermal priming time model, usually used for modeling the effect of priming on germination rate of nondormant seeds, was successfully applied to dormancy release resulting from the hydration treatments.

Heart rate responses and plasma cortisol concentrations in ewes: comparison between cervical and laparoscopic intrauterine insemination and their associated handling procedures

1998 ◽  
Vol 66 (2) ◽  
pp. 383-387 ◽  
Author(s):  
M. Khalid ◽  
W. Haresign ◽  
D. G. Bradley
Keyword(s):  
Heart Rate ◽  
Stress Responses ◽  
Plasma Cortisol ◽  
Intrauterine Insemination ◽  
Management Practice ◽  
Treatment Groups ◽  
Cortisol Responses ◽  
The Mean ◽  
Pre Treatment ◽  
Mean Heart Rate

AbstractThis study consisted of two experiments. In experiment 1, stress responses of sheep which were restrained either in a laparoscopy cradle or a roll-over cradle were compared. The results of this experiment indicated that restraint in roll-over cradle is less (P < 0·05) stressful than that in a laparoscopy cradle when assessed in terms of the elevation and duration of both the mean heart rate and plasma cortisol responses. Experiment 2 compared the stress responses of sheep subjected to restraint in a laparoscopy cradle, restraint in a laparoscopy cradle with intrauterine artificial insemination (AI) by laparoscopy, minimal restraint with cervical AI or restraint in a roll-over cradle plus foot-trimming. All treatments resulted in significant elevations in both heart rate and plasma cortisol concentrations (F < 0·001). The peak heart rate was significantly (P < 0·05) higher in ewes subjected to cervical AI than in those subjected to intrauterine insemination, with other treatments intermediate. The peak cortisol response did not differ among different treatments. The duration over which both the mean heart rate and -plasma cortisol concentrations remained significantly elevated above pre-treatment concentrations did not differ among treatment groups. The results of this study suggest that while restraint using a laparoscopy cradle is more stressful than that using a rollover cradle, the stress inflicted by intrauterine insemination by laparoscopy itself is no greater than that due to restraint using the laparoscopy cradle alone, cervical AI or the management practice offoot-trimming using a rollover cradle.

Genetic Diversity among Calamus brandisii Becc. (Arecaceae) Populations in Kerala Part of Western Ghats

2021 ◽  
Vol 43 (1) ◽  
pp. 38-42
Author(s):  
Kavungal Priya ◽  
◽  
Indira . ◽  
Vadakkethil Balakrishnan Sreekumar ◽  
Renuka . ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Western Ghats ◽  
Rapd Markers ◽  
Gene Diversity ◽  
Issr Markers ◽  
High Genetic Diversity ◽  
Western Ghats Of India ◽  
The Mean ◽  
Two Parameters ◽  
Two Populations

Calamus brandisii Becc. is one of the endemic slender rattans found in the Western Ghats of India. The genetic diversity of two main populations available in Kerala was investigated using 20 RAPD and 9 ISSR markers. Two parameters viz., gene diversity and genetic diversity within and among populations were analyzed. ISSR analysis showed quite high genetic diversity in Pandimotta compared to Bonacaud population whereas in RAPD markers both these populations were moderately diverse. The percentage of total genetic differentiation (Gst) among two populations is relatively higher than the mean Gst value indicating high genetic diversity within the populations. The genetic distance between these two populations was 0.1739 with ISSR markers and 0.1971 with RAPD markers. Because of its high genetic diversity, Pandimotta population can be treated as an important population of gene diversity with potentially useful genes. This may be included in the high priority reservoir for genetic conservation also.

scholarly journals Temperature Dependent Seed Germination of Dalbergia nigra Allem (Leguminosae)

2001 ◽  
Vol 44 (4) ◽  
pp. 401-404 ◽  
Author(s):  
Fernanda G. A. Ferraz-Grande ◽  
Massanori Takaki
Keyword(s):  
Seed Germination ◽  
Endangered Species ◽  
High Temperatures ◽  
Broad Temperature Range ◽  
Optimum Temperature ◽  
Temperature Dependent ◽  
Temperature Range ◽  
Dalbergia Nigra ◽  
The Mean ◽  
Kinetics Of

The germination of endangered species Dalbergia nigra was studied and 30.5° C was found as optimum temperature, although the species presented a broad temperature range where germination occurs and light had no effect. The analysis of kinetics of seed germination confirmed the asynchronized germination below and above the optimum temperature. The light insensitive seed and germination also at high temperatures indicated that D. nigra could occur both in understories and gaps where the mean temperature was high.

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