scholarly journals Seed Germination and Seedling Growth of the Endangered Azorean Cherry Prunus azorica

HortScience ◽  
2012 ◽  
Vol 47 (9) ◽  
pp. 1222-1227 ◽  
Author(s):  
Orlanda Cristina Barros Moreira ◽  
José Martins ◽  
Luís Silva ◽  
Mónica Moura
Keyword(s):  
Seed Germination ◽  
Growth Regulator ◽  
Incubation Temperature ◽  
Seed Morphology ◽  
Laurel Forest ◽  
Life Project ◽  
Temperature Regimes ◽  
Physiological Dormancy ◽  
Priority Species ◽  
Alternating Temperature

Prunus azorica is an Azorean endemic tree considered as a priority species for conservation. It is important as a laurel forest component, particularly at medium altitude, and as a food source for the endangered bird Pyrrhula murina. The best conditions for seed germination were investigated after removal of the outer layers of the fruit by determining the effect of 1) using stones or seeds; 2) stratification regime (six treatments and a control); 3) incubation temperature (four alternating temperature regimes); and 4) gibberellic acid concentration (three levels). This resulted in a fully factorial design with 168 (2 × 7 × 4 × 3) treatments with three replicates per treatment and 25 seeds per replicate. Cumulative germination percentages were determined at the end of the trial. Globally, there was a significant effect of endocarp removal (49% germination with seeds and 15% with stones). Both for stones and seeds, there was a significant effect of incubation temperature, stratification regime, and growth regulator concentration. Stones attained a maximum germination of ≈80% under several stratification treatments including cold (4 °C) or warm (20 °C) followed by cold and at 10/5 °C without the addition of a growth regulator. Seeds attained a maximum germination of greater than 90% without stratification at 10/5 or 15/10 °C without the addition of a growth regulator. During the stratification process, germination occurred only for seeds, particularly for longer treatments, for example, those corresponding to 3 or more months of stratification, including warm followed by cold (75% to 80%) or cold alone (77%). According to seed morphology and germination results, the seed appears to have a non-deep physiological dormancy. Seeds of P. azorica can thus be efficiently germinated after endocarp removal at temperatures of 10/5 or 15/10 °C with a daily light period of 12 hours. This protocol allowed producing hundreds of viable seedlings that were used in the reforestation of a laurel forest stand in a LIFE project.

Dormancy break and germination requirements in acorns of two bottomland Quercus species (Sect. Lobatae) of the eastern United States with references to ecology and phylogeny

2020 ◽  
Vol 30 (3) ◽  
pp. 199-205
Author(s):  
Tracy S. Hawkins
Keyword(s):  
United States ◽  
Cold Stratification ◽  
Eastern United States ◽  
Closely Related Species ◽  
Temperature Regimes ◽  
Quercus Species ◽  
Physiological Dormancy ◽  
Alternating Temperature ◽  
Incubation Temperatures ◽  
Germination Requirements

AbstractQuercus species are ecologically and economically important components of deciduous forests of the eastern United States. However, knowledge pertinent to a thorough understanding of acorn germination dynamics for these species is lacking. The objectives of this research were to determine dormancy break and germination requirements for acorns of two eastern United States bottomland species, Quercus nigra and Quercus phellos (Section Lobatae), and to present results within ecological and phylogenetic contexts. Three replicates of 50 acorns of each species received 0 (control), 6, 12 or 18 weeks of cold stratification, followed by incubation in alternating temperature regimes of 15/6, 20/10, 25/15 and 30/20°C. Eighteen weeks of cold stratification were not sufficient for dormancy break in Q. nigra acorns. Cumulative germination percentages at 4 weeks of incubation were ≥77%, but only in incubation temperatures of 25/15 and 30/20°C. Dormancy break in Q. phellos acorns was achieved with 18 weeks of cold stratification, and cumulative germination percentages were ≥87% at 4 weeks of incubation in all test temperature regimes. Gibberellic acid solutions were not an effective substitute for cold stratification in either species. Phylogenetically, Q. nigra and Q. phellos are closely related species and, ecologically, both grow in the same habitat. Acorns of both species possess deep physiological dormancy (PD), but dormancy break and germination requirements differ in acorns of these two Quercus species.

scholarly journals Effects of Environmental Factors on Seed Germination and Emergence of Velvetleaf (Abutilon theophrasti)

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
RC. XIONG ◽  
Y. MA ◽  
HW. WU ◽  
WL. JIANG ◽  
XY. MA
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Field Experiments ◽  
Cropping Systems ◽  
Control Strategies ◽  
Seedling Emergence ◽  
Central China ◽  
Burial Depth ◽  
Temperature Regimes ◽  
Alternating Temperature

ABSTRACT: Velvetleaf, an annual broadleaf weed, is a common and troublesome weed of cropping systems worldwide. Laboratory and field experiments were conducted to determine the effects of environmental factors on germination and emergence of velvetleaf. Seeds germinated over a range of constant temperatures from 10 to 40 oC regardless of light conditions, but no germination occurred at temperature below 5 oC and beyond 50 oC. Seeds germinated at alternating temperature regimes of 15/5 to 40/30 oC, with maximum germination (>90%) at alternating temperatures of 40/30 oC. Germination was sensitive to water stress, and only 0.4% of the seeds germinated at the osmotic potential of -0.4 MPa. There was no germination at ? 0.6 MPa. Moreover, germination was reduced by saline and alkaline stresses and no germination occurred at ³ 150 mM NaCl or ³ 200 mM NaHCO3 concentrations. However, pH values from 5 to 9 had no effect on seed germination. Seedling emergence was significantly affected by burial depth and maximum emergence (78.1-85.6%) occurred at the 1-4 cm depth. The results of this study have contributed to our understanding of the germination and emergence of velvetleaf and should enhance our ability to improve control strategies in cropping systems in central China.

scholarly journals Seed germination of Solanum spp. (Solanaceae) for use in rehabilitation and commercial industries

2008 ◽  
Vol 56 (4) ◽  
pp. 333 ◽  
Author(s):  
L. E. Commander ◽  
D. J. Merritt ◽  
D. P. Rokich ◽  
G. R. Flematti ◽  
K. W. Dixon
Keyword(s):  
Seed Germination ◽  
Food Industry ◽  
Incubation Temperature ◽  
Solanum Species ◽  
Seed Embryo ◽  
Physiological Dormancy ◽  
Incubation Temperatures ◽  
Smoke Water ◽  
Solanum Spp ◽  
Seeds Germination

Effective methods for propagation of native Solanum species are required for mine rehabilitation and the native food industry in Australia. This study investigated seed germination of eight native Solanum species with respect to incubation temperature and the efficacy of germination-promoting compounds gibberellic acid (GA3), the butenolide isolated from smoke (karrikinolide, KAR1) and smoke water (SW). Seeds of all species were tested under a temperature regime of 26/13°C or 33/18°C. In these conditions, seeds of only two species, S. cunninghamii Benth. and S. phlomoides Benth. germinated to high levels without treatment. Of the remaining six species, GA3 alone promoted germination in S. chippendalei Symon, S. diversiflorum F.Muell. and S. sturtianum F.Muell., whereas GA3, KAR1 and SW were effective at promoting germination of S. centrale J.M.Black, S. dioicum W.Fitzg. and S. orbiculatum Dunal ex Poir. to varying degrees. Additional incubation temperatures (10, 15, 20, 25 and 30°C) were examined for S. centrale and S. orbiculatum. For both species, broadly similar patterns were noted in the response of seeds to GA3, KAR1 and SW across all temperatures. However, for S. centrale seeds, germination percentages were higher at 26/13°C than at any of the constant temperatures, and there was a trend of increasing germination with increasing constant temperature for S. orbiculatum seeds. Analysis of seed embryo type and imbibition characteristics and consideration of the subsequent germination results indicates that dormant Solanum seeds possess physiological dormancy.

Comparison of germination responses of cultivated wheat ( Triticum ) and its wild relative ( Aegilops ) species under salinity, temperature and light

2007 ◽  
Vol 55 (4) ◽  
pp. 407-415 ◽  
Author(s):  
M. Yildiz ◽  
E. Kasap
Keyword(s):  
Seed Germination ◽  
Inhibitory Effect ◽  
Wild Relative ◽  
Wheat Cultivars ◽  
Wheat Species ◽  
Wild Wheat ◽  
Light Levels ◽  
Temperature Regimes ◽  
Salinity Levels ◽  
Alternating Temperature

The seed germination of bread ( Triticum aestivum cv. Bezostaya 1 and Ceyhan 99) and durum ( Triticum durum cv. Diyarbakır 81 and Fırat 93) wheat species and their wild relative species ( Aegilops biuncialis and Ae. triuncialis ) was compared at two light levels, nine NaCl concentrations and three alternating temperature regimes. No seeds germinated at 675 mmol/L NaCl. The highest seed germination (100%) of cultivated wheat cultivars was noted in the control at 15/25°C and 20/30°C, and that of wild wheat species in both the control and the 150 mmol/L NaCl treatment under all temperature regimes. The seed germination of bread and durum wheat cultivars was completely inhibited at or above 450 and 375 mmol/L NaCl, respectively. No Ae. biuncialis seeds germinated at 600 mmol/L NaCl, while seeds of Ae. triuncialis germinated at this concentration (38.9%) only at 20/30°C in darkness. The inhibitory effect of light on germination in all genotypes was determined in some salinity levels at 15/25°C. The optimal germination treatment for all genotypes was 15/25°C temperature regime and darkness. The inhibitory effect of high salinity on germination was greater at 25/35°C than at 15/25°C or 20/30°C. In salinity and temperature interactions, the seeds of wild wheat species were found to be more tolerant than those of wheat cultivars.

scholarly journals Ecology of Musk Thistle (Carduus nutans) Seed Germination for Grasslands of Temperate Climates

Weed Science ◽  
2013 ◽  
Vol 61 (4) ◽  
pp. 549-556 ◽  
Author(s):  
Chengchou Han ◽  
Stephen L. Young
Keyword(s):  
Seed Germination ◽  
Perennial Grass ◽  
Management Strategies ◽  
Temperate Grasslands ◽  
Invasive Weed ◽  
Light Levels ◽  
Temperature Regimes ◽  
Alternating Temperature ◽  
Reduced Light ◽  
Temperate Climates

Musk thistle is an invasive weed that is widely distributed throughout much of North America, including grasslands in temperate climates of the midwest USA. A series of laboratory and greenhouse experiments were conducted to determine the effect of various environmental factors on germination of musk thistle seeds. In temperature-fluctuation experiments, seed germination was greater than 65% in both alternating (30/20 C) and constant (20 or 25 C) temperature regimes with an 8-h day but less (33%) in warmer regimes (35/20 C). Germination of musk thistle seeds was 37% in alternating temperature regimes of 30/20 C in total darkness, but less than 67% in pots in the greenhouse. Differences of 10 and 15 C between day and night temperatures resulted in 91 and 75% maximum germination of musk thistle, respectively. Increasingly dryer soils reduced germination of musk thistle seeds from 35% (−0.03 MPa) to 0% (−1.2 MPa), whereas saline soils (> 80 mM) reduced maximum germination to less than 10%. Musk thistle seeds collected from populations in a bare-ground area had 96% germination, which was greater than that of seeds collected from populations growing in a perennial grass pasture (71%). A residence time (i.e., period that seeds remained on the parent plant) of 9 to 12 wk after capitulum maturity resulted in seeds germinating more quickly than those dispersed earlier. Overall, reduced light levels, cool and fluctuating temperatures, and amount of time seeds remained in residence are some of the most important factors that contribute to germination of musk thistle seeds. Information on germination dynamics of musk thistle seeds provides an understanding of the interactions that affect this process and underscores the importance of timely management strategies in temperate grasslands.

Germination strategy of Allium victorialis, a wild edible plant with high commercial potential

Botany ◽  
2017 ◽  
Vol 95 (2) ◽  
pp. 195-202
Author(s):  
Rina Kamenetsky ◽  
Joanna Gębura ◽  
Krystyna Winiarczyk
Keyword(s):  
Seed Germination ◽  
Edible Plant ◽  
Natural Habitats ◽  
Spring Ephemeral ◽  
Temperature Regimes ◽  
Physiological Dormancy ◽  
Germination Techniques ◽  
Nutraceutical Properties ◽  
New Crop ◽  
Germination Strategy

The spring ephemeral Allium victorialis grows naturally in Europe, Asia, and North America. Because of its pleasant taste, aroma, and nutraceutical properties, it is intensively gathered in its natural habitats by the local populations. To introduce A. victorialis as a new crop, technologies of mass-propagation and effective production must be developed. However, the biology of seed dormancy and germination in this species is not clear, and numerous attempts at controlled seed germination have not succeeded. We employed a systematic approach for seed germination of this species under controlled conditions. Two main factors, post-ripening seed age and germination temperature regimes, were studied in combination with various germination techniques. As opposed to common conceptions, our results show that the seeds of A. victorialis do not experience morphological, physical, or physiological dormancy, and are completely ready for germination immediately following ripening. Propagation of A. victorialis from seed can be performed by germination of fresh seeds at moderate (20 °C) temperatures, in a sterile planting medium with good aeration. The germination strategy, revealed in this research, opens new prospects for the development of A. victorialis as a new and useful crop.

scholarly journals Intermediate Epicotyl Physiological Dormancy in the Recalcitrant Seed of Quercus chungii F.P.Metcalf with the Elongated Cotyledonary Petiole

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 263
Author(s):  
Xi-Qing Sun ◽  
Yi-Gang Song ◽  
Bin-Jie Ge ◽  
Xi-Ling Dai ◽  
Gregor Kozlowski
Keyword(s):  
Seed Germination ◽  
Seed Morphology ◽  
Embryo Axis ◽  
Seed Plant ◽  
Plant Adaptation ◽  
Recalcitrant Seed ◽  
Cotyledonary Petiole ◽  
Quercus Species ◽  
Physiological Dormancy ◽  
Shoot Emergence

Control of seed germination and dormancy is important in seed plant adaptation and evolution. When studying seed dormancy of Quercus species, we observed a substantially delayed shoot emergence following a fast root emergence in Quercus chungii F.P.Metcalf. Since epicotyl physiological dormancy (PD) has not been reported in Quercus section Cyclobalanopsis, we examined seed morphology and germination in Q. chungii and aimed to document epicotyl PD in the seeds. The embryo was fully developed in fresh ripe seeds. The elongating cotyledonary petiole pushed the embryo axis out of the seed during germination, which differed from observations in other Quercus species. Shoots emerged from seeds with developing roots after 3 months of warm stratification (35/25 °C), reaching the highest percentage of shoot emergence in seeds after 5 months. Seeds were recalcitrant and displayed a yet unreported epicotyl PD type, for which we propose the formula Cnd(root) ‒ Cp’’ 2b(shoot). Early emergence and development of the root system in Q. chungii seeds with epicotyl PD appears to be a mechanism to maintain a constant water supply to the shoot during plumule development and emergence. Our documentation of seed germination will provide guidance for the conservation and restoration of this species from seeds.

Can alternating temperature, moist chilling, and gibberellin interchangeably promote the completion of germination in Clematis vitalba seeds?

Botany ◽  
2017 ◽  
Vol 95 (8) ◽  
pp. 847-852 ◽  
Author(s):  
Rosangela Picciau ◽  
Marco Porceddu ◽  
Gianluigi Bacchetta
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Plant Species ◽  
Temperature Regime ◽  
Fluctuating Temperature ◽  
Temperature Regimes ◽  
Moist Chilling ◽  
Clematis Vitalba ◽  
Alternating Temperature ◽  
Positive Effect

Each plant species has particular requirements for seed germination, and some of them respond differently to constant or alternating temperature regimes. In this study, the interchangeable effects of different treatments and temperatures on the completion of seed germination of Clematis vitalba L. were investigated. The seeds were tested with a constant (from 5 °C to 25 °C) or a fluctuating (25/10 °C) temperature regime, and the effect of gibberellic acid (GA3), incubation at warm (W) or cold (C) temperatures while being imbibed, and drying after ripening (DAR) were evaluated. The final germination percentages and the time in days required to reach 50% of germination (T50) were calculated. GA3 and C significantly enhanced completion of seed germination at all of the temperatures tested. A strong positive effect of alternating temperature was observed, which triggered completion of seed germination regardless of treatment. Under the fluctuating temperature, the chilled seeds had the most rapid germination. Low germination rates were observed for both control and DAR treatments. Seeds of C. vitalba display a certain degree of dormancy, which can be broken by moist chilling and GA3 treatments. Moreover, alternating temperature stimulates the completion of seed germination by satisfying certain physiological requirements for germination under constant temperatures.

scholarly journals Seed dormancy and germination characteristics of Acer cinnamomifolium, a plant species endemic to China

2021 ◽  
Author(s):  
Cui-Fang Tang ◽  
Yu-Chen Zhao ◽  
Lin-Feng Ou ◽  
Cai-Hong Zhong ◽  
Song-Quan Song
Keyword(s):  
Seed Germination ◽  
Plant Species ◽  
Seed Dormancy ◽  
Environmental Changes ◽  
Effect Of Temperature ◽  
Cold Stratification ◽  
Dormancy Release ◽  
Temperature Regimes ◽  
Germination Characteristics ◽  
Alternating Temperature

Seed dormancy is an adaptive response of plants to environmental changes during long-term evolution. It plays an important role in plant survival and propagation. Acer cinnamomifolium, a plant species endemic to China, is an excellent garden and street tree species. However, dormancy and germination characteristics of A. cinnamomifolium seeds are not currently known. In the present paper, the mature seeds were used as experimental materials and we investigated the effect of temperature including alternating temperature, light, after-ripening, stratification and phytohormone on seed dormancy release and germination. After being incubated for 30 days, 0 to 10% of the seeds germinated in constant temperature (10, 15, 20, 25 and 30°C), while in alternating temperature regimes (20/10, 25/15 and 30/20°C), seed germination was < 35%. Dormancy release and germination of seeds can be increased by after-ripening, cold stratification and phytohormone treatments. We concluded that A. cinnamomifolium seeds have a non-deep physiological dormancy. Cold stratification at 4°C for 30 days and incubation thereafter at 20°C were found to be optimal for dormancy release and high seed germination.

Germination Characteristics of Three Species ofCruciferae

Weed Science ◽  
1970 ◽  
Vol 18 (1) ◽  
pp. 41-48 ◽  
Author(s):  
James A. Young ◽  
Raymond A. Evans ◽  
Richard O. Gifford ◽  
Richard E. Eckert
Keyword(s):  
Soil Moisture ◽  
Incubation Temperature ◽  
Moisture Stress ◽  
Soil Samples ◽  
Total Degree ◽  
Temperature Dependent ◽  
Soil Moisture Stress ◽  
Temperature Regimes ◽  
Germination Characteristics ◽  
Alternating Temperature

Germination of tumble mustard (Sisymbrium altissimumL.), tansy mustard (Descurainia pinnata(Walt.) Britton), and yellowflower pepperweed (Lepidium perfoliatumL.) is partially dependent on total degree hours of incubation (temperature above 0 C times the duration of incubation). This relation was similar under constant or alternating temperatures. Alternating temperature regimes with −20 C inhibited germination, and greatly depressed subsequent germination at optimum temperatures. Tansy mustard and yellowflower pepperweed have temperature-dependent after-ripening requirements. Germination of all three species responded similarly to osmotic stress. The relation between tumble mustard germination under osmotic or soil moisture stress is dependent on the texture of the soil substrate. A mucilaginous coating greatly aids the germination of yellowflower pepperweed seeds on the surface of media under low (0.05 to 0.2 bars) moisture tension. Germination of seeds of the three species recovered in soil samples from the field is radically different from that of freshly harvested material. The seeds acquire a dormancy which is broken irregularly under ideal conditions for germination.

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