Seed stratification and germination strategy in the Mediterranean pines Pinus brutia and P. halepensis

1995 ◽  
Vol 5 (3) ◽  
pp. 151-160 ◽  
Author(s):  
Antonis Skordilis ◽  
Costas A. Thanos
Keyword(s):  
Seed Germination ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Red Light ◽  
Pinus Brutia ◽  
Temperature Range ◽  
Promotive Effect ◽  
Germination Behaviour ◽  
Mediterranean Pine ◽  
Of Greece

AbstractThe ecophysiology of germination in Pinus brutia and P. halepensis was studied in seeds collected from different areas of Greece. In regard to the temperature range of germination, both P. halepensis and the southern provenance (Lasithi, Crete) of the East Mediterranean pine, P. brutia, follow a typical Mediterranean pattern. In the latter species, dramatic differences in the degree of dormancy were noted among the three provenances investigated; in all seed lots however, 20°C was clearly the optimal temperature for germination. Stratification resulted in a considerable promotion of P. brutia seed germination. Nevertheless, the inductive effect of stratification was shown to differ among the three provenances used, escalating from a simple increase of germination rate (in the southern seed lot from Lasithi, Crete) through a broadening of the temperature range of germination (in the intermediate lot from Thasos Island) to, finally, a dramatic release from a particularly deep dormancy (in the northern lot from Soufli). These deeply dormant seeds of the latter provenance displayed an absolute stratification requirement; prolonged illumination or seed coat scarification could not substitute for the promotive effect of prechilling. A considerable interaction between far-red light and stratification was revealed in the dormant seeds of P. brutia (Soufli provenance); far-red pulses during stratification could either cancel or diminish the germination promotion induced by low temperatures. The differences observed in the germination behaviour among the various P. brutia provenances may be attributed to a variable ecophysiological strategy in regard to the temporal pattern of seedling emergence and establishment. According to the variants of this strategy, seed germination is timed to occur during either spring (in regions with relatively cold and moist climates), or autumn and early winter (in southern, mild and dry areas) or both (in intermediate conditions).

scholarly journals Factors affecting Cyperus difformis seed germination and seedling emergence

2013 ◽  
Vol 31 (4) ◽  
pp. 823-832 ◽  
Author(s):  
A. Derakhshan ◽  
J. Gherekhloo
Keyword(s):  
Seed Germination ◽  
Integrated Management ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Soil Surface ◽  
Weed Species ◽  
Factors Affecting ◽  
Cyperus Difformis ◽  
Emergence Patterns

Specific knowledge about the dormancy, germination, and emergence patterns of weed species aids the development of integrated management strategies. Laboratory studies were conducted to determine the effect of several environmental factors on seed germination and seedling emergence of Cyperus difformis. Germination of freshly harvested seeds was inhibited by darkness; however, when seeds were subsequently transferred to complete light they germinated readily. Our results showed that 2 wk of cold stratification overcome the light requirement for germination. Seeds of C. difformis were able to germinate over a broad range of temperatures (25/15, 30/20, 35/25, and 40/30 ºC day/night). The response of germination rate to temperature was described as a non-linear function. Based on model outputs, the base, the optimum and the ceiling temperatures were estimated as 14.81, 37.72 and 45 ºC, respectively. A temperature of 120 ºC for a 5 min was required to inhibit 50% of maximum germination. The osmotic potential and salinity required for 50% inhibition of maximum germination were -0.47 MPa and 135.57 mM, respectively. High percentage of seed germination (89%) was observed at pH=6 and decreased to 12% at alkaline medium (pH 9) pH. Seeds sown on the soil surface gave the greatest percentage of seedling emergence, and no seedlings emerged from seeds buried in soil at depths of 1 cm.

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 Effects of Different Priming Treatments on Seed Germination Properties, Yield Components and Grain Yield of Lentil (Lens culinaris Medik.)

2015 ◽  
Vol 43 (1) ◽  
pp. 153-158 ◽  
Author(s):  
Faruk TOKLU
Keyword(s):  
Seed Germination ◽  
Grain Yield ◽  
Yield Components ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Yield Component ◽  
Field Conditions ◽  
Distilled Water ◽  
Peg 6000 ◽  
Positive Effects

An experiment was conducted under laboratory and field conditions in order to evaluate the effects of different priming treatments, specifically KNO3 (1%), KCl (2%), KH2PO4 (1%), ZnSO4 (0.05%), PEG-6000 (20%), IBA (100 ppm), Mannitol (4%), GA3 (100 ppm) and distilled water, on seed germination properties and several agro-morphological plant characteristics of red lentil. Seeds not primed were used as a control. GA3 treatment increased shoot length. The control (non-primed seeds) treatment resulted in increased seedling root number and length. Distilled water, ZnSO4 and control treatments increased germination rate and percentage. In the pot experiments, GA3 treatment increased plant height and seedling emergence rate, whereas KCl treatment improved the number of nodules, as well as root and shoot dry weight when compared to the control. ZnSO4 treatment increased yield components and grain yield in field conditions. The results of this study showed that ZnSO4, GA3 and PEG-6000 seed priming treatments may be useful tools due to their positive effects on germination rate, germination percentage, yield component and grain yield of lentil.

scholarly journals Impact of Environmental Factors on Seed Germination and Seedling Emergence of White Clover (Trifolium repens L.)

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 190
Author(s):  
Lei Chu ◽  
Yiping Gao ◽  
Lingling Chen ◽  
Patrick E. McCullough ◽  
David Jespersen ◽  
...  
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
White Clover ◽  
Trifolium Repens ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Soil Surface ◽  
High Sensitivity ◽  
Series Of Experiments ◽  
Trifolium Repens L

White clover (Trifolium repens L.) is cultivated as a forage crop and planted in various landscapes for soil conservation. There are numerous reports of failed white clover stands each year. A good understanding of the seed germination biology of white clover in relation to environmental factors is essential to achieve successful stand establishment. A series of experiments were conducted to investigate the impacts of light, temperature, planting depth, drought, and salt stress on seed germination and the emergence of white clover. White clover is negatively photoblastic, and seed germination averaged 63 and 66% under light and complete dark conditions 4 weeks after planting (WAP), respectively. Temperature affected the seed germination speed and rate. At 1 WAP, seeds incubated at 15 to 25 °C demonstrated a significantly higher germination rate than the low temperatures at 5 and 10 °C; however, the germination rate did not differ among the temperature treatments at 4 WAP. The results suggest that white clover germination decreases with increasing sowing depths, and the seeds should be sown on the soil surface or shallowly buried at a depth ≤1 cm to achieve an optimal emergence. White clover seeds exhibited high sensitivity to drought and salinity stress. The osmotic potential and NaCl concentration required to inhibit 50% seed germination were −0.19 MPa and 62.4 mM, respectively. Overall, these findings provide quantifiable explanations for inconsistent establishment observed in field conditions. The results obtained in this research can be used to develop effective planting strategies and support the successful establishment of white clover stands.

scholarly journals Arabidopsis chloroplast J protein DJC75/CRRJ mediates nitrate-promoted seed germination in the dark

2020 ◽  
Vol 125 (7) ◽  
pp. 1091-1099
Author(s):  
Huai-Syuan Ciou ◽  
Yu-Lun Tsai ◽  
Chi-Chou Chiu
Keyword(s):  
Arabidopsis Thaliana ◽  
Seed Germination ◽  
Germination Rate ◽  
Red Light ◽  
Phytochrome B ◽  
Biosynthetic Gene ◽  
Unknown Mechanism ◽  
J Domain ◽  
Domain Protein ◽  
J Protein

Abstract Background and Aims Nitrate can stimulate seed germination of many plant species in the absence of light; however, the molecular mechanism of nitrate-promoted seed germination in the dark remains largely unclear and no component of this pathway has been identified yet. Here, we show that a plastid J-domain protein, DJC75/CRRJ, in arabidopsis (Arabidopsis thaliana) is important for nitrate-promoted seed germination in the dark. Methods The expression of DJC75 during imbibition in the dark was investigated. The seed germination rate of mutants defective in DJC75 was determined in the presence of nitrate when light cues for seed germination were eliminated by the treatment of imbibed seeds with a pulse of far-red light to inactivate phytochrome B (phyB), or by assaying germination in the dark with seeds harbouring the phyB mutation. The germination rates of mutants defective in CRRL, a J-like protein related to DJC75, and in two chloroplast Hsp70s were also measured in the presence of nitrate in darkness. Key Results DJC75 was expressed during seed imbibition in the absence of light. Mutants defective in DJC75 showed seed germination defects in the presence of nitrate when light cues for seed germination were eliminated. Mutants defective in CRRL and in two chloroplast Hsp70s also exhibited similar seed germination defects. Upregulation of gibberellin biosynthetic gene GA3ox1 expression by nitrate in imbibed phyB mutant seeds was diminished when DJC75 was knocked out. Conclusions Our data suggest that plastid J-domain protein DJC75 regulates nitrate-promoted seed germination in the dark by upregulation of expression of the gibberellin biosynthetic gene GA3ox1 through an unknown mechanism and that DJC75 may work in concert with chloroplast Hsp70s to regulate nitrate-promoted seed germination. DJC75 is the first pathway component identified for nitrate-promoted seed germination in the dark.

Comparative studies on salt tolerance of seedlings for one cultivar of puccinellia (Puccinellia ciliata) and two cultivars of tall wheatgrass (Thinopyrum ponticum)

2005 ◽  
Vol 45 (4) ◽  
pp. 391 ◽  
Author(s):  
B. Zhang ◽  
B. C. Jacobs ◽  
M. O'Donnell ◽  
J. Guo
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Seed Germination ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Salt Tolerant ◽  
Mineral Contents ◽  
Shoot Height ◽  
Thinopyrum Ponticum ◽  
Tall Wheatgrass

Salt tolerances of 3 cultivars, Menemen puccinellia (Puccinellia ciliata Bor), Tyrrell and Dundas [tall wheatgrass, Thinopyrum ponticum (Podp.) Z. W. Liu and R. R. C. Wang], were compared with respect to their seed germination, adaptive responses to salt and waterlogging, seedling emergence, plant growth, shoot osmolality and mineral contents in a series of salt-stress experiments. An inverse normal distribution provided good fits for the time to seed germination. Under NaCl stress, 50% of the control (distilled water) seed germination rates of Menemen, Tyrrell and Dundas were achieved in 178.8, 300.9 and 296.8 mmol/L NaCl, respectively. Fifty percent of the control seedling emergence rates of these 3 cultivars were in 92.7, 107.2 and 113.5 mmol/L NaCl, respectively. The seed germination rates of these 3 cultivars under both salt and waterlogging stress were far lower than those germinated only under salt stress at the same salt level. Seed pretreatment by soaking seed in NaCl solutions greatly increased the seed germination rate under salt stress for Menemen and under both salt stress and waterlogging for Dundas. Tyrrell and Dundas were very similar in their tolerance to salt stress, and were significantly (P<0.05) more salt tolerant than Menemen in terms of seed germination and seedling emergence rate. Both shoot height and dry matter of these 3 cultivars were not statistically different among all salt stress levels during the seedling elongation period, indicating that the established plants of these 3 cultivars were very salt tolerant. The salt tolerance mechanisms of these 3 cultivars are possibly related to their abilities to maintain high osmolality in shoots by regulating high sodium and potassium contents, and reducing calcium deficiency under salt stress.

Quantitative trait loci associated with lettuce seed germination under different temperature and light environments

Genome ◽  
2008 ◽  
Vol 51 (11) ◽  
pp. 928-947 ◽  
Author(s):  
Eiji Hayashi ◽  
Natsuyo Aoyama ◽  
David W. Still
Keyword(s):  
Quantitative Trait Loci ◽  
Seed Germination ◽  
Path Analysis ◽  
Quantitative Trait ◽  
Germination Rate ◽  
Red Light ◽  
Seed Maturation ◽  
Lettuce Seed ◽  
Factors Affecting ◽  
Trait Loci

Temperature and light are primary environmental cues affecting seed germination. To elucidate the genetic architecture underlying lettuce ( Lactuca sativa L.) seed germination under different environmental conditions, an F8 recombinant inbred line population consisting of 131 families was phenotyped for final germination and germination rate. Seeds were imbibed in water at 20 °C under continuous red light (20-Rc), 20 °C continuous dark (20-Dc), 31.5 °C continuous red light (31.5-Rc), 31.5 °C continuous dark (31.5-Dc), or 20 °C far-red light for 24 h followed by continuous dark (20-FRc-Dc). Thirty-eight quantitative trait loci (QTL) were identified from two seed maturation environments: 10 for final germination and 28 for germination rate. The amount of variation attributed to an individual QTL ranged from 9.3% to 17.2% and from 5.6% to 26.2% for final germination and germination rate, respectively. Path analysis indicated that factors affecting germination under 31.5-Rc or 31.5-Dc are largely the same, and these appear to differ from those employed under 20-FRc-Dc. QTL and path analysis support the notion of common and unique factors for germination under diverse temperature and light regimes. A highly significant effect of the seed maturation environment on subsequent germination capacity under environmental stress was observed.

Japanese Foxtail (Alopecurus japonicus) Management in Wheat in China: Seed Germination, Seedling Emergence, and Response to Herbicide Treatments

2017 ◽  
Vol 32 (2) ◽  
pp. 211-220 ◽  
Author(s):  
Hengzhi Wang ◽  
Yizhao Huang ◽  
Lele Zhang ◽  
Weitang Liu ◽  
Jinxin Wang
Keyword(s):  
Seed Germination ◽  
Integrated Management ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Integrated Approach ◽  
Growth Stages ◽  
Ph Values ◽  
Grass Weed ◽  
Different Growth Stages

AbstractLittle information is published related to seed germination and seedling emergence of Japanese foxtail, a troublesome annual grass weed widely distributed in winter wheat fields in China. Three Japanese foxtail populations were studied under laboratory and greenhouse conditions, to determine the effects of different environmental factors on seed germination or seedling emergence. Chemical control is absolutely necessary in integrated management, and efficacy of POST herbicides against different growth stages of Japanese foxtail was evaluated. Germination rate was 90% or more when temperature ranged from 5 to 25 C, with germination onset shortened as temperature increased. Light was not required for germination to occur. For pH values ranging from 5 to10 there was no effect on seed germination. Japanese foxtail seed germination was sensitive to osmotic stress and completely inhibited at an osmotic potential of -1.1 MPa. The ‘1513’ population of Japanese foxtail demonstrated tolerance to soil salinity, with 98% germination at 80 mM NaCl compared with 25 and 40% germination for populations ‘1532’ and ‘1544’, respectively. High amounts of crop residue (10 t ha−1) suppressed Japanese foxtail emergence 38 to 55%. Germination of seeds placed at 160 C for 5 min was completely inhibited for dry seeds, with a similar effect at 130 C for pre-soaked seeds. Seed burial in the soil from 0 to 4 cm had no effect on seedling emergence, but burial at 7 cm completely inhibited seedling emergence. POST herbicides mesosulfuron-methyl (13.5 g ai ha−1), clodinafop-propargyl (67.5 g ai ha−1), pyroxsulam (13.5 g ai ha−1), pinoxaden (67.5 g ai ha−1) and isoproturon (1125 g ai ha−1) reduced plant dry weight 80% or more when applied at three- to seven-leaf stage, but control declined with application at later growth stages. The information from this study helps to develop an integrated approach to Japanese foxtail management.

scholarly journals Germination and seed conservation of a pioneer species, Tecoma stans (Bignoniaceae), from tropical dry forest of Colombia

2018 ◽  
Vol 66 (2) ◽  
pp. 918
Author(s):  
Jhon Alexander Vargas-Figueroa ◽  
Alba Marina Torres-González
Keyword(s):  
Seed Germination ◽  
White Light ◽  
Germination Rate ◽  
Red Light ◽  
Tropical Dry Forest ◽  
Seed Storage ◽  
Dry Forest ◽  
Storage Behavior ◽  
Mean Germination Time ◽  
Seed Storage Behavior

Seed germination and seed longevity under different environmental conditions are fundamental to understand the ecological dynamics of a species, since they are decisive for its success within the ecosystem. Taking this into account, seed germination and seed storage behavior of a pioneer species of tropical dry forest (Tecoma stans) were studied in the laboratory, to establish the effect of different environmental conditions on a local tree population. Two seed lots collected in July 2011, from Cali (Colombia), were evaluated under three alternating temperatures (20/30, 20/25, 25/30 ºC; 16/8 h) and four light qualities (12-hour white light photoperiod, darkness, and 15 minutes of red light -R and far red light -FR). Final germination was recorded for all treatments; for white light treatment the daily germination was recorded to calculate mean germination rate, mean germination time, and two synchronization indices. To assess the effect of light quality on physiological variables, a destructive germination test was carried out. For this test, another seed lot was evaluated under the same light conditions using an alternating temperature of 20/30 °C - 16/8 h, recording germination during six days for every treatment. In addition, seeds were stored at two different moisture contents (7.7, 4.1 %) and three storage temperatures (20, 5, -20 ºC), during two time periods (one and three months); a seed germination test was conducted for each treatment. Four replicates of 35 seeds per treatment were used for all experiments. Germination was high (GP > 90 %) with all alternating temperatures under white light, whereas under R, FR, and darkness germination was evenly successful at low temperatures, but at higher temperature, half of the seeds entered into secondary dormancy (GP= 45-65 %). However, mean germination rate and synchronization under R and FR decreased significantly in comparison to white light treatment and, consequently, mean germination time increased. Seed storage behavior of this species is orthodox due to the high germination (GP > 90 %) obtained under all treatments. In conclusion, T. stans seeds have a negative germination response at high incubation temperatures in the absence of white light, entering into a secondary dormancy. In contrast, an environment with a lower temperature and without white light delays the germination, but at the end seeds are able to reach the same germination values. This seed dependence on incident light in limiting conditions suggests a physiological mechanism on the seed tissues of this species, probably mediated by phytochromes. Finally, the orthodox seed storage behavior of T. stans is a reason to include this species in ex situ seed conservation programs for restoration and recovery of the tropical dry forest; however, long-term studies should be conducted in order to evaluate the maintenance of this characteristic throughout longer periods of time. Rev. Biol. Trop. 66(2): 918-936. Epub 2018 June 01. 

scholarly journals Effects of Temperature on Seed Germination of Invasive Plant Rorippa amphbia (L.) Besser

2019 ◽  
pp. 1-7
Author(s):  
Yufeng Xu ◽  
Miao Liu ◽  
Yuanhao Lv ◽  
Qiuli Wang ◽  
Bo Qu ◽  
...  
Keyword(s):  
Global Warming ◽  
Seed Germination ◽  
Filter Paper ◽  
Invasive Plant ◽  
Germination Rate ◽  
Petri Dish ◽  
Liaoning Province ◽  
Germination Index ◽  
Temperature Range ◽  
Germination Potential

Aims: Global warming and biological invasion are major environmental issues faced in the world. In the study, Rorippa amphibia, a perennial invasive clone plant in northern China, was used as a material to study the germination characteristics of the seeds at different temperatures. Study Design: Germination test of R. amphibia seeds at different temperature was studied by means of laboratory culture. The germination percentage, germination index, germination potential, bud height and root length of the seeds were determined. Place and Duration of Study: Samples were collected from the west side of the swimming pool of Shenyang Agricultural University of Liaoning Province in August 2017. Experiments were done in the College of Biological Science and Technology, between October 2017 and June 2018. Methodology: The petri dish method was used in the experiment. Fifty seeds were randomly selected and soaked in distilled water for 12h. The seeds were placed in a petri dish covered with double filter paper, cultured at 10℃, 15℃, 20℃, 25℃, 30℃, 35℃ and 40℃ in light incubators for 12h darkness and 12h light (4000lux), with 3 repeats per processing. Seed germination was based on embryo root breakthrough seed coat ≥ 1 mm. During the experiment, the numbers of seed germination were recorded every day, and the filter paper was kept moist until there was no new seed germination for 2 consecutive days, which was regarded as the end of germination. The numbers of seed germination should be counted regularly every day, and the beginning and duration of germination should be recorded. The germination rate, daily germination rate, germinating potential, germinating index and vigor index of R. amphibia seeds at different temperature were calculated by measuring bud height and radicle length on the 10th day after germination. Results: The temperature range of seed germination of R. amphibia was wide, which could germinate at 15 - 40℃. Lower temperature delayed the peak period of seed germination at some extent and the germination rates of R. amphibia peak at 30 - 35℃, which were 44.67% and 50% respectively. At 35℃, germination potential and germination index were 25.33% and 29.46, reaching the maximum value. Conclusion: The reason for the wide temperature range of seed germination and the low germination rate might be the candidate method for clonal plant population establishment in temperate zone. The higher germination rate of high temperature condition suggested that clone invasive plants in temperate regions were more invasive during global warming.

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