scholarly journals What can routine germination tests in seed banks tell us about the germination ecology of endemic and protected species?

Botany ◽  
2017 ◽  
Vol 95 (7) ◽  
pp. 673-684 ◽  
Author(s):  
Adelaide S. Clemente ◽  
Jonas V. Müller ◽  
Erika Almeida ◽  
Catarina A. Costa ◽  
Sara Lobo Dias ◽  
...  
Keyword(s):  
Seed Bank ◽  
Incubation Temperature ◽  
In Situ Conservation ◽  
Germination Percentage ◽  
Test Case ◽  
Physical Dormancy ◽  
Germination Ecology ◽  
Physiological Dormancy ◽  
Mean Germination Time ◽  
Major Factors

Protocols for the conservation of threatened plants are often constrained by the absence of data on germination ecology. However, seed bank managers periodically monitor the viability of stored seed collections using germination tests. Here, we argue that data from those tests can and should be used to provide information on germination requirements of threatened species. Twelve taxa endemic to Portugal were used as a test case to determine the effect of incubation temperature and pretreatments upon germination and to identify major factors eliciting germination and releasing dormancy. We achieved maximum germination percentages >95% for nine taxa. Temperature significantly affected the final germination and mean germination time in most taxa. Maximum and faster germination at cool temperatures (15 °C or alternate 20/10 °C) was the prevailing trend. Cold stratification improved germination in one species, suggesting physiological dormancy. Scarification increased the germination percentage of one species among those expected to exhibit physical dormancy. Seed bank data provided valuable information on germination ecology, which can be used in in-situ conservation and as a baseline for further germination studies. Given the increasing threats to plant diversity, accessibility to seed bank data are paramount.

scholarly journals Evaluation of several methods for breaking dormancy of bitter vetch seeds (Vicia ervilia L.)

2015 ◽  
Vol 71 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Hossein Reza Rouhi ◽  
Ali Sepehri ◽  
Leila Sefidkhani ◽  
Fatemeh Karimi
Keyword(s):  
Germination Percentage ◽  
Hot Water ◽  
The Other ◽  
Cold Stratification ◽  
Distilled Water ◽  
Breaking Dormancy ◽  
Bitter Vetch ◽  
Physiological Dormancy ◽  
Mean Germination Time ◽  
Germination Parameters

Abstract This study analysed the effects of different treatments on breaking dormancy and germination of bitter vetch (Vicia ervilia L.) freshly harvested seeds for seeding immediately. Partial scarified seeds (30 seconds with sandpaper) were subjected to different treatments including: GA3 (250, 500 and 750 ppm), KNO3 (0.1, 0.2 and 0.3% w/v), cold stratification (2, 4 and 6 days), sulfuric acid (25, 50 and 75 seconds), hot water (90°C; for 2.5 and 5 minutes), hydropriming via seed soaking in distilled water (4 and 8 hours) and mechanical scarification. Among the mentioned treatments, cold stratification for 6 days had a best effect on germination related parameters final germination percentage, mean germination time and vigour indexthan the other periods. In contrast to scarification with acid and hot water, mechanical scarification improved germination parameters but this effect was lower than the cold stratification. The results suggest that bitter vetch seed has both physical and physiological dormancy.

Dormancy breakage in Cercis chinensis seeds

2020 ◽  
Vol 100 (6) ◽  
pp. 666-673
Author(s):  
Yunpeng Gao ◽  
Mingwei Zhu ◽  
Qiuyue Ma ◽  
Shuxian Li
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Germination Percentage ◽  
Physical Dormancy ◽  
Optimal Method ◽  
Hard Seed ◽  
Positive Effects ◽  
Physiological Dormancy ◽  
Hard Seed Coat

The seeds of Cercis chinensis Bunge are important for reproduction and propagation, but strong dormancy controls their germination. To elucidate the causes of seed dormancy in C. chinensis, we investigated the permeability of the hard seed coat and the contribution of the endosperm to physical dormancy, and we examined the effect of extracts from the seed coat and endosperm. In addition, the effectiveness of scarification methods to break seed dormancy was compared. Cercis chinensis seeds exhibited physical and physiological dormancy. The hard seed coat played an important role in limiting water uptake, and the endosperm acted as a physical barrier that restricted embryo development in imbibed seeds. Germination percentage of Chinese cabbage [Brassica rapa subsp. chinensis (L.) Hanelt] seeds was reduced from 98% (control) to 28.3% and 56.7% with a seed-coat extract and an endosperm extract, respectively. This demonstrated that both the seed coat and endosperm contained endogenous inhibitors, but the seed-coat extract resulted in stronger inhibition. Mechanical scarification, thermal scarification, and chemical scarification had positive effects on C. chinensis seed germination. Soaking non-scarified seeds in gibberellic acid (GA3) solution did not promote germination; however, treatment with exogenous GA3 following scarification significantly improved germination. The optimal method for promoting C. chinensis seed germination was soaking scarified seeds in 500 mg·L−1 GA3 for 24 h followed by cold stratification at 5 °C for 2 mo.

scholarly journals Breaking of dormancy in the narrow endemic Jasione supina Sieber subsp. supina (Campanulaceae) with small seeds that does not need the light to germinate

2020 ◽  
Vol 80 (1) ◽  
Author(s):  
Gürcan Güleryüz ◽  
Serap Kırmızı ◽  
Hülya Arslan ◽  
Elif Güleryüz
Keyword(s):  
Germination Percentage ◽  
Dormancy Breaking ◽  
Short Term ◽  
Germination Time ◽  
Physiological Dormancy ◽  
Moist Chilling ◽  
Dark Regime ◽  
Mean Germination Time ◽  
The Mean

The germination properties of Jasione supina Sieber subsp. supina (Campanulaceae), which is endemic to Mount Uludağ, Bursa, Turkey, were determined. In this study, we investigated the effects of GA3, the combination of hormone series and short-term moist chilling (1-month), and long-term moist chilling (4-month) on the germination percentage and mean germination time in relation to seed dormancy breaking. All treatment series were incubated under continuous dark (20 °C, 24 h) and light/dark (20/10 °C, 12/12 h) conditions. Seeds were collected from specimens widespread on alpine and subalpine grasslands and dwarf shrubs of Mount Uludağ (1800-1900 m a.s.l.). Depending on the concentration, GA3 and the combination of hormone and moist chilling treatments promoted seed germination in both dark and light/dark conditions. After 4-month-moist chilling treatment, seeds germinated 27% in light/dark and 80% in dark regime. Hormone and moist chilling treatments reduced the mean germination time. Our results showed that J. supina seeds have physiological dormancy, require prolonged times of moist chilling and preferentially complete germination in darkness.

scholarly journals Sensitivity of Seed Germination to Salt Stress in Black Cumin (Nigella sativa L.)

2018 ◽  
Vol 46 (1) ◽  
pp. 202-205 ◽  
Author(s):  
Panayiota PAPASTYLIANOU ◽  
Nikolia-Nonika BAKOGIANNI ◽  
Ilias TRAVLOS ◽  
Ioannis ROUSSIS
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Nigella Sativa ◽  
Germination Percentage ◽  
Oilseed Crop ◽  
Black Cumin ◽  
Germination Time ◽  
Randomized Design ◽  
Mean Germination Time ◽  
Major Factors

Black cumin is an annual oilseed crop, native to the Mediterranean region and widely used for nutritional and medicinal purposes. Reduced seed germination and early seedling growth under saline conditions are considered as major factors limiting the establishment of crops. The objective of this study was to investigate the effect of salinity due to NaCl on germination of black cumin seeds. A set of experiments was conducted under completely randomized design with four replications of 200 seeds at two different suboptimal germination temperatures (15 and 20 °C) in the dark for 16 days. In order to create salt stress conditions during the germination process, five solutions were used (0 as control, 80, 160, 240 and 320 mM NaCl). The germination performance was evaluated by final germination percentage and mean germination time. The effect of salinity on seed germination percentage and mean germination time was significant at p<0.01. Germination of the controls was 96% and 95% at 15 °C and 20 °C, respectively. The presence of NaCl, regardless of temperature, reduced germination. This reduction was more severe at 15 °C (15%, and 19% germination in cases of 80 and 160 mM concentration respectively) than at 20 °C (65% at 80 mM salinity level) and no germination was observed from 240 mM onwards. The mean germination time increased with increased NaCl levels, especially at the lower temperature of 15 °C. The overall results of this experiment showed the inhibitory effects of salt stress on seed germination parameters of black cumin.

Bromus tectorum seed germination: between-population and between-year variation

1996 ◽  
Vol 74 (6) ◽  
pp. 875-882 ◽  
Author(s):  
Julie Beckstead ◽  
Susan E. Meyer ◽  
Phil S. Allen
Keyword(s):  
Seed Germination ◽  
Bromus Tectorum ◽  
Incubation Temperature ◽  
Weather Conditions ◽  
Germination Percentage ◽  
Maximum Temperature ◽  
Germination Time ◽  
Germination Response ◽  
Mean Germination Time ◽  
Contrasting Habitats

Cheatgrass (Bromus tectorum L., Poaceae), an introduced winter annual, has invaded a variety of habitats in western North America. This study examines variation in cheatgrass germination response and after-ripening patterns that are related to differences in habitat and to yearly differences in weather conditions during seed maturation. Seeds collected from five contrasting populations in 1992 and 1993 were subjected to controlled dry storage and then incubated across a range of temperatures. Recently harvested seeds were dormant and germinated slowly, while fully after-ripened seeds were nondormant and germinated rapidly. The optimal incubation temperature for mean germination time shifted from 5:15 to 20:30 °C as a result of after-ripening. Between-population differences in germination response appear to be related to the potential risk of precocious summer germination. The results from this 2-year study suggest that the more extreme yet predictable environments select for seed germination and after-ripening patterns that are genetically fixed, while populations from more favorable environments tended to show more between-year variations, suggesting more phenotypic plasticity. Germination percentage showed greater between-year variation than mean germination time. Between-year differences could not be explained simply by differences in maximum temperature or total precipitation during maturation. Adaptive germination responses in cheatgrass populations from contrasting habitats may have both genetic and environmental components, thus explaining why this species can become established in such a variety of habitats. Keywords: after-ripening, invading species, dormancy, mean germination time, cheatgrass, downy brome.

scholarly journals Effect of seed coat rupture on the germination of Mimosa flocculosa Burkart (Leguminosae) seeds

Hoehnea ◽  
2020 ◽  
Vol 47 ◽  
Author(s):  
Maiara Iadwizak Ribeiro ◽  
Guilherme Almeida Garcia Rodrigues ◽  
Gabriele Larissa Mathias ◽  
Shirley Martins Silva ◽  
Jaqueline Malagutti Corsato ◽  
...  
Keyword(s):  
Seed Coat ◽  
Native Species ◽  
Large Scale ◽  
Germination Percentage ◽  
Distilled Water ◽  
Seedling Production ◽  
Physical Dormancy ◽  
Anatomical Analysis ◽  
Heated Water ◽  
Mean Germination Time

ABSTRACT Mimosa flocculosa Burkart is a native species used for the recovery of degraded areas. Large scale seedling production in nurseries is hindered due to seed physical dormancy. This study evaluated the germination and seed coat anatomy of M. flocculosa seeds subjected to dormancy overcome treatments. Seeds of M. flocculosa were subjected to: control with distilled water, heated water at 50, 80 and 100 °C, and H2SO4 for 1, 3 and 5 minutes. Germination tests were conducted with four replicates of 25 seeds in an entirely casualized delineation, analyzing germination percentage, mean germination time and germination speed index. Moreover, anatomical analysis of the seed coat was conducted. The treatments with heated water at 80 ºC, and sulfuric acid for 3 and 5 minutes promoted benefic anatomical alterations in the seed integument, reflecting in higher and faster in germination rates. Heated water at 80 ºC is recommended because of its efficiency and safety.

Morphophysiological dormancy and germination ecology in diaspores of the subtropical palm Phoenix canariensis Chabaud

Botany ◽  
2021 ◽  
Author(s):  
Lanlan He ◽  
Ganesh K. Jaganathan ◽  
Baolin Liu
Keyword(s):  
Seed Dormancy ◽  
Seedling Emergence ◽  
Primary Root ◽  
Germination Percentage ◽  
Early Summer ◽  
Germination Ecology ◽  
Phoenix Canariensis ◽  
Morphophysiological Dormancy ◽  
Cotyledonary Petiole ◽  
Seed Dormancy And Germination

The timing of germination is a crucial event in a plant’s life cycle. Seed dormancy and germination mechanisms are important factors regulating seedling emergence. Since detailed experimental evidence for germination pattern of Phoenix canariensis colonizing sub-tropical climate is scarce, we investigated seed dormancy and germination ecology of P. canariensis. We found that the embryo is underdeveloped at the time of dispersal and doubles in size before the cotyledonary petiole (CP) protrudes through the operculum. The primary root and plumule emerge from the elongated CP outside the seed. In light/dark at 30/25°C, the CP emerged from 8% of the diaspores within 30 days and from 76% within 14 weeks. Thus, 8% of the diaspores have MD and the others MPD. Removal of the pericarp and operculum resulted in 100% germination within 5 days in light/dark at 30/25°C. Cold and warm stratification as well as treatment with GA3 significantly increased the germination speed, but the final germination percentage was not significantly increased. Seed germination was synchronized in early summer when seed dormancy was released by cold stratification in the soil over winter. A remote-tubular germination type and intricate root system provide an ecological advantage to the seedling establishment.

scholarly journals Phytotoxicity of Chitosan and SiO2 Nanoparticles to Seed Germination of Wheat (Triticum aestivum L.) and Barley (Hordeum vulgare L.) Plants

2017 ◽  
Vol 9 (2) ◽  
pp. 242-249 ◽  
Author(s):  
Faride BEHBOUDI ◽  
Zeinalabedin TAHMASEBI SARVESTANI ◽  
Mohamad Zaman KASSAEE ◽  
Seyed Ali Mohamad MODARES SANAVI ◽  
Ali SOROOSHZADEH
Keyword(s):  
Germination Rate ◽  
Dry Weight ◽  
Sio2 Nanoparticles ◽  
Triticum Aestivum L ◽  
Germination Percentage ◽  
Hordeum Vulgare L ◽  
Randomized Design ◽  
Direct Exposure ◽  
Contrast Exposure ◽  
Mean Germination Time

Plants such as wheat and barley that are strategically important crops need to be considered to develop a comprehensive toxicity profile for nanoparticles (NPs). The present study was aimed to investigate the effects of chitosan and SiO2 NPs on wheat and barley plants. Two factorial experiments (seeds priming and direct exposure) were performed based on a completely randomized design in four replications. Results showed that the seeds priming with the NPs had not significant effect on germination parameters such as Germination Percentage (GP), Germination Rate (GR), Germination Value (GV), Mean Germination Time (MGT), Pick Value (PV) and Mean Daily Germination (MDG). In contrast, exposure of the seeds to the NPs had significant effects on these parameters. In both experiments, treatments had significant effects on shoot, seedling, root length, fresh and dry weight, as well as vigor indexes as compared to the control. In most traits, the best concentration of NPs was 30 ppm, whereas applications of the NPs with 90 ppm displayed adverse effects on majority of the studied traits. According to these results, selectivity in applications of NPs with suitable concentration and method is essential for different plant species.  

Seed development in Malva parviflora: onset of germinability, dormancy and desiccation tolerance

2007 ◽  
Vol 47 (6) ◽  
pp. 683 ◽  
Author(s):  
Pippa J. Michael ◽  
Kathryn J. Steadman ◽  
Julie A. Plummer
Keyword(s):  
Moisture Content ◽  
Seed Development ◽  
Desiccation Tolerance ◽  
Dry Weight ◽  
Physical Dormancy ◽  
Seed Moisture Content ◽  
Physiological Maturity ◽  
Seed Moisture ◽  
Physiological Dormancy ◽  
Malva Parviflora

Seed development was examined in Malva parviflora. The first flower opened 51 days after germination; flowers were tagged on the day that they opened and monitored for 33 days. Seeds were collected at 12 stages during this period and used to determine moisture content, germination of fresh seeds and desiccation tolerance (seeds dried to 10% moisture content followed by germination testing). Seed moisture content decreased as seeds developed, whereas fresh (max. 296 mg) and dry weight (max. 212 mg) increased to peak at 12–15 and ~21 days after flowering (DAF), respectively. Therefore, physiological maturity occurred at 21 DAF, when seed moisture content was 16–21%. Seeds were capable of germinating early in development, reaching a maximum of 63% at 9 DAF, but germination declined as development continued, presumably due to the imposition of physiological dormancy. Physical dormancy developed at or after physiological maturity, once seed moisture content declined below 20%. Seeds were able to tolerate desiccation from 18 DAF; desiccation hastened development of physical dormancy and improved germination. These results provide important information regarding M. parviflora seed development, which will ultimately improve weed control techniques aimed at preventing seed set and further additions to the seed bank.

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