scholarly journals Effect of Osmotic Potential on Seed Germination and Biochemical Indices of different Christ's thorn (Ziziphus spina–christi) Populations

2021 ◽  
Vol 8 (1) ◽  
pp. 1-22
Author(s):  
Mahnaz Mansouri ◽  
◽  
Ali Moradi ◽  
Hamidreza Balouchi ◽  
Elias Soltani ◽  
...  
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Biochemical Indices

Effect of Environmental Factors on Germination and Emergence of Shortawn Foxtail (Alopecurus aequalis)

Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Ning Zhao ◽  
Qi Li ◽  
Wenlei Guo ◽  
Lele Zhang ◽  
Lu’an Ge ◽  
...  
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Control Strategies ◽  
Abiotic Factors ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Burial Depth ◽  
Effective Measure ◽  
Wide Range

Shortawn foxtail is an invasive grass weed infesting winter wheat and canola production in China. A better understanding of the germination ecology of shortawn foxtail would help to develop better control strategies for this weed. Experiments were conducted under laboratory conditions to evaluate the effects of various abiotic factors, including temperature, light, pH, osmotic stress, salt concentration, and planting depth, on seed germination and seedling emergence of shortawn foxtail. The results showed that the seed germination rate was greater than 90% over a wide range of constant (5 to 25C) and alternating (15/5 to 35/25C) temperatures. Maximum germination occurred at 20C or 25/15C, and no germination occurred at 35C. Light did not appear to have any effect on seed germination. Shortawn foxtail germination was 27% to 99% over a pH range of 4 to 10, and higher germination was obtained at alkaline pH values ranging from 7 to 10. Seed germination was sensitive to osmotic potential and completely inhibited at an osmotic potential of −0.6 MPa, but it was tolerant to salinity: germination even occurred at 200 mM NaCl (5%). Seedling emergence was highest (98%) when seeds were placed on the soil surface but declined with the increasing burial depth. No seedlings emerged when seeds were buried 6-cm deep. Deep tillage could be an effective measure to limit seed germination from increased burial depth. The results of this study will lead to a better understanding of the requirements for shortawn foxtail germination and emergence and will provide information that could contribute to its control.

scholarly journals Seed germination ecology of Conyza stricta Willd. and implications for management

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244059
Author(s):  
Safdar Ali ◽  
Fakhar Din Khan ◽  
Rehmat Ullah ◽  
Rahmat Ullah Shah ◽  
Saud Alamri ◽  
...  
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Cropping Systems ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Conservation Agriculture ◽  
Weed Species ◽  
Seed Burial ◽  
Germination Ecology ◽  
Tillage Practices

Numerous cropping systems of the world are experiencing the emergence of new weed species in response to conservation agriculture. Conyza stricta Willd. is being a newly emerging weed of barley-based cropping systems in response to conservational tillage practices. Seed germination ecology of four populations (irrigated, rainfed, abandoned and ruderal habitats) was studied in laboratory and greenhouse experiments. The presence/absence of seed dormancy was inferred first, which indicated seeds were non-dormant. Seed germination was then recorded under various photoperiods, constant and alternating day/night temperatures, and pH, salinity and osmotic potential levels. Seedling emergence was observed from various seed burial depths. Seeds of all populations proved photoblastic and required 12-hour light/dark period for germination. Seeds of all populations germinated under 5–30°C constant temperature; however, peak germination was recorded under 17.22–18.11°C. Nonetheless, the highest germination was noted under 20/15°C alternating day/night temperature. Ruderal and irrigated populations better tolerated salinity and germinated under 0–500 mM salinity. Similarly, rainfed population proved more tolerant to osmotic potential than other populations. Seeds of all populations required neutral pH for the highest germination, whereas decline was noted in germination under basic and alkaline pH. Seedling emergence was retarded for seeds buried >2 cm depth and no emergence was recorded from >4 cm depth. These results add valuable information towards our understanding of seed germination ecology of C. stricta. Seed germination ability of different populations under diverse environmental conditions suspects that the species can present severe challenges in future if not managed. Deep seed burial along with effective management of the emerging seedlings seems a pragmatic option to manage the species in cultivated fields. However, immediate management strategies are needed for rest of the habitats.

Moisture Stress and Hydration-Dehydration Effects on Hemp Sesbania (Sesbania exaltata) Seed Germination

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 487-492 ◽  
Author(s):  
Robert D. Williams
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Moisture Stress ◽  
Germination Percentage ◽  
Moisture Uptake ◽  
Sesbania Exaltata ◽  
Hemp Sesbania ◽  
Number Of Cycles

Increased osmotic potential from 0 to −14 bars decreased the moisture uptake and germination of mechanically scarified hemp sesbania [Sesbania exaltata(Raf.) Cory] seed. Germination percentage for osmotic potential of 0, −2, −4, −6, and −8 bars was 86%, 86%, 70%, 19%, and 1%, respectively. This response to moisture stress was modified by imbibition, or hydration-dehydration, of the seed prior to the moisture stress. Imbibing the seed for as little as 2 h significantly increased its subsequent germination against moisture stress. One hydration-dehydration cycle had little or no effect on germination, but as the number of cycles increased, the germination percentage decreased. Prolonged hydration of 3 and 7 days followed by dehydration greatly reduced subsequent seed germination.

Factors affecting seed germination of annual sowthistle (Sonchus oleraceus) in southern Australia

Weed Science ◽  
2006 ◽  
Vol 54 (5) ◽  
pp. 854-860 ◽  
Author(s):  
Bhagirath S. Chauhan ◽  
Gurjeet Gill ◽  
Christopher Preston
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Field Experiments ◽  
Soil Depth ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Factors Affecting ◽  
Control Programs ◽  
Buried Seed ◽  
Ph Range

Annual sowthistle has become more abundant under no-till systems in southern Australia. Increased knowledge of germination biology of annual sowthistle would facilitate development of effective weed control programs. The effects of environmental factors on germination and emergence of annual sowthistle seeds were examined in laboratory and field experiments. Seeds of annual sowthistle were able to germinate over a broad range of temperatures (25/15, 20/12, and 15/9 C day/night temperatures). Seed germination was favored by light; however, some germination occurred in the dark as well. Greater than 90% of seeds germinated at a low level of salinity (40 mM NaCl), and some seeds germinated even at 160 mM NaCl (7.5%). Germination decreased from 95% to 11% as osmotic potential increased from 0 to −0.6 MPa and was completely inhibited at osmotic potential greater than −0.6 MPa. Seed germination was greater than 90% over a pH range of 5 to 8, but declined to 77% at pH 10. Seedling emergence was the greatest (77%) for seeds present on the soil surface but declined with depth, and no seedlings emerged from a soil depth of 5 cm. In another experiment in which seeds were after-ripened at different depths in a field, seed decay was greater on the soil surface than at 2 or 5 cm depth. At the end of the growing season, there was a much greater persistence of buried seed (32 to 42%) than seeds present on the soil surface (8%). Greater persistence of buried seed could be due to dormancy enforced by dark in this species.

Distribution, Growth, and Seed Germination Ability of Lead Tree (Leucaena leucocephala) Plants in Penghu Islands, Taiwan

2010 ◽  
Vol 24 (4) ◽  
pp. 574-582
Author(s):  
Chen-Yu Hwang ◽  
Ling-Ming Hsu ◽  
Yow-Jang Liou ◽  
Ching-Yuh Wang
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Optimal Time ◽  
Growth Stages ◽  
Burial Depth ◽  
Lighting Condition ◽  
Germination Ability ◽  
Shallow Soils ◽  
Penghu Islands ◽  
Germination Requirements

The distribution, growth, and seed germination ability of the exotic lead tree in Penghu Islands, Taiwan, were studied. Survey results have shown that all lead tree plants existing throughout these islands belonged to the Hawaii type. Subsequently a comparison of germination requirements between this and the rare Salvador type, which distributes only in the island of Taiwan, was carried out. The objective of this research was to compare the germination requirements of the Salvador- and Hawaii-type lead tree plants. Lead trees in Penghu Islands have formed a pure forest with a height ranging from 2 to 4 m. All growth stages of the lead tree, i.e., vegetative, flowering, podding, and depodding stages, were found simultaneously in fall, but only vegetative and podding stages were observed in summer. Germination of both the Hawaii- and Salvador-type lead tree was evaluated under different environmental conditions, including temperature, pH, osmotic potential, burial depth, and lighting condition. The Salvador-type exhibited more than 60% seed germination after 14 d at temperatures between 20 and 35 C, whereas the seed germination of the Hawaii type increased from 20 to 60% with temperature increases from 20 to 35 C. The optimal temperature for seed germination of these two types of lead tree was 35 C. Increasing burial depth beneath the soil surface and darkness, as well as an osmotic potential below −0.4 MPa, also reduced seed germination. However, the germination of both types was not affected by pH ranging from 4.0 to 9.0. On the basis of the climatic and soil environment conditions in Penghu Islands, it is reasonable to predict that the summer season, in which lead tree seeds readily germinate on the ground or in shallow soils, is the optimal time for controlling this plant.

Biochemical and cytological studies on osmoprimed maize seeds

1995 ◽  
Vol 5 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Felipe Cruz García ◽  
Luis F. Jiménez ◽  
Jorge M. Vázquez-Ramos
Keyword(s):  
Cell Division ◽  
Seed Germination ◽  
Osmotic Potential ◽  
Storage Conditions ◽  
Maize Seeds ◽  
Embryo Axes ◽  
Osmotic Agent ◽  
Biochemical Level ◽  
Mitotic Figures ◽  
Root Tissues

AbstractThe conditions of osmopriming of maize seeds have been established. At an osmotic potential of–1.7 MPa, seed germination is inhibited and seeds osmoprimed for up to 3 weeks show an improved germinability when the osmotic agent is removed. This improvement also applies to seeds that lost vigour because of improper storage conditions. At the biochemical level, embryo axes from osmoprimed seeds can incorporate precursors into DNA, RNA and proteins although at a low level; after removing the osmotic agent, all 3 types of macromolecules are synthesized at much higher levels. No evidence of DNA replication or cell division was found during osmopriming; however, mitotic figures appear several hours earlier in germinated, osmoprimed root tissues compared with the time at which they appear in non-osmoprimed tissues. The behaviour of osmoprimed maize is compared with that of osmoprimed seeds from other plant species.

scholarly journals Improving Dormancy and Germination of Piquín Chili Pepper (Capsicum annuum var. glabriusculum) by Priming Techniques

2018 ◽  
Author(s):  
Maria Fernanda Quintero Castellanos ◽  
Oscar Guillen Castillo ◽  
Pablo Delgado Sánchez ◽  
José Marín Sánchez ◽  
Ana Isabel Guzmán Carrasco ◽  
...  
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Seedling Establishment ◽  
Osmotic Potential ◽  
Seedling Emergence ◽  
Chili Pepper ◽  
Basic Information ◽  
Negative Effect

The effects of different priming techniques were evaluated to improve the dormancy and germination of wild seeds of “Piquín” chili pepper. Three experiments were designed for pre-sowing treatment of seeds: a) chemical seeds digestion; b) halopriming (with K+ or NH4+ of NO3-, SO42- or Cl-) at different priming times (24, 48 or 72 h) and osmotic potential (-5, -10 or -15 atm) and c) previously selected halopriming (KNO3 and NH4NO3) + Gibberellic acid (GA3, at 100 or 200 ppm) were tested. Digestion treatments did show a negative effect on seed germination. Recommended values of osmotic potential (Ψs), to improve Piquín chili seed germination, must be between -10 and -15 atm (-1.0 and -1.5 MPa) and the priming time must be between 48 and 72 hours. Priming techniques can considerably reduce Capsaicinoids content on seeds, improve dormancy, seed germination performance, and increase the rate and uniformity of seedling establishment. KNO3 and secondly GA3 treatments may improve rapid and uniform germination and seedling emergence. The results provide basic information to develop guidelines for commercial establishment of Piquín pepper crops.

scholarly journals Osmotic Priming or Chilling Stratification Improves Seed Germination of Purple Coneflower

HortScience ◽  
1994 ◽  
Vol 29 (12) ◽  
pp. 1445-1448 ◽  
Author(s):  
N. Wartidiningsih ◽  
R.L. Geneve ◽  
S.T. Kester
Keyword(s):  
Polyethylene Glycol ◽  
Seed Germination ◽  
Osmotic Potential ◽  
Echinacea Purpurea ◽  
Germination Percentage ◽  
Polyethylene Glycol 4000 ◽  
Purple Coneflower ◽  
High Germination

High germination seed lots of purple coneflower [Echinacea purpurea (L.) Moench] were evaluated for laboratory germination following osmotic priming or chilling stratification. Compared to nontreated seeds, osmotic priming at 25C in salts (KNO3 + K3PO4; 1:1, w/w) or polyethylene glycol 4000 (PEG) increased early (3-day) germination percentage at 27C of all seed lots, and improved total (10-day) germination percentage of low-germination seed lots. Total germination percentage was unaffected or increased by priming for 4 days compared to 8 days, and by priming at –1.0 MPa compared to –0.5 MPa (except for one low-germination seed lot). Chilling stratification in water at 5 or 10C increased early and total germination of all seed lots, except for that same lot, compared to nontreated seeds. Total germination percentage was unaffected or increased by stratification at 10C rather than at 5C. Neither extending stratification ≥20 days nor lowering osmotic potential with PEG during stratification improved total germination percentage.

Incubation under fluctuating temperatures reduces mean base water potential for seed germination in several non-cultivated species

2005 ◽  
Vol 15 (2) ◽  
pp. 89-97 ◽  
Author(s):  
Roberto Huarte ◽  
Roberto L. Benech-Arnold
Keyword(s):  
Seed Germination ◽  
Water Potential ◽  
Osmotic Potential ◽  
Quantitative Description ◽  
Maximum Temperature ◽  
The Mean ◽  
Hydrotime Model ◽  
Total Seed ◽  
Base Water Potential ◽  
Fluctuating Temperatures

Seeds ofCarduus acanthoides,Cynara cardunculus,Cirsium vulgare,Brassica campestris, andSisymbrium altissimumwere incubated at a range of decreasing osmotic potentials (Ψo) under fluctuating temperatures or the median temperature of the fluctuation cycle. Fluctuating temperatures promoted total seed germination in water and at reduced osmotic potential. Total germination was reduced as the Ψodecreased. However, this trend was smallest under fluctuating temperatures, signalling a higher tolerance of seeds to reduced osmotic potential. Effects of osmoticum and temperature were modelled with the hydrotime model. The parameters estimated from the model, the hydrotime constant (θH), the mean base water potential Ψb(50) and its standard deviation (σΨb) gave good descriptions of germination time courses. For all species, incubation under fluctuating temperatures shifted Ψb(50) values downwards without modifying their distribution substantially. This accounted for the greater tolerance of germination to reduced Ψounder fluctuating temperatures. To confirm that these effects were mediated by temperature fluctuationsper se, the behaviour ofC. acanthoidesandC. cardunculusincubated at the minimum, the mean and the maximum temperature of the fluctuation cycle was also analysed. Constant maximum and minimum temperatures of the cycle did not stimulate germination, nor did they shift Ψb(50) towards more negative values. The hydrotime model provides a physiologically based quantitative description for germination promotion due to fluctuating temperature.

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