scholarly journals Seed Germination of Dirca (Leatherwood): Pretreatments and Interspecific Comparisons

HortScience ◽  
2005 ◽  
Vol 40 (6) ◽  
pp. 1838-1842 ◽  
Author(s):  
James A. Schrader ◽  
William R. Graves
Keyword(s):  
Seed Germination ◽  
San Francisco ◽  
Germination Percentage ◽  
Eastern North America ◽  
Cold Stratification ◽  
Natural Conditions ◽  
In The Wild ◽  
Northeastern Mexico ◽  
Understory Shrubs ◽  
Interspecific Comparisons

The genus Dirca L. (Thymelaeaceae) consists of three species of understory shrubs. Dirca palustris L. is sparsely distributed across eastern North America, D. occidentalis Gray is endemic near the San Francisco Bay, and D. mexicana Nesom & Mayfield is known only in one population in northeastern Mexico. Despite interest in the horticultural use of Dirca, plants seldom are marketed. Difficult propagation impedes production of Dirca. We sought to define protocols that promote uniform seed germination of all three Dirca spp. Endodormancy and paradormancy cause sporadic germination over several years under natural conditions, but endocarp removal, cold stratification, and treatment with GA3 increased germination percentage, speed, and uniformity. Dirca occidentalis was most responsive; up to 94% of seeds germinated after endocarp removal, 24 hours in GA3 at 50 mg·L–1, and stratification at 4 °C for 30 days. Treatments also were effective for D. palustris (up to 68% germination), but seeds of D. mexicana were unresponsive and germinated at 25% or less. Seed treatments should facilitate production of D. occidentalis and D. palustris, but further research is needed to define methods to propagate D. mexicana for horticultural use and for conserving this rare species in the wild.

Habitat-correlated seed germination behaviour in populations of wood anemone (Anemone nemorosa L.) from northern Italy

2008 ◽  
Vol 18 (4) ◽  
pp. 213-222 ◽  
Author(s):  
Andrea Mondoni ◽  
Robin Probert ◽  
Graziano Rossi ◽  
Fiona Hay ◽  
Costantino Bonomi
Keyword(s):  
Seed Germination ◽  
Embryo Development ◽  
Northern Italy ◽  
Natural Conditions ◽  
Mountain Site ◽  
Radicle Emergence ◽  
In The Wild ◽  
Soil Temperatures ◽  
Shoot Emergence ◽  
Mountain Population

AbstractAlthough various aspects of the biology of Anemone nemorosa have been examined, few studies present data on seed germination, and even then information tends to be rather contradictory. A. nemorosa L. is a spring-flowering, woodland geophyte, widely distributed across much of Europe. Germination phenology, including embryo development and radicle and shoot emergence, were investigated in one mountain and three lowland populations from northern Italy. Immediately after harvest, seeds were either sown on agar in the laboratory under simulated seasonal temperatures, or placed in nylon mesh sachets and buried in the wild. Embryos, undifferentiated at the time of dispersal, grew under summer conditions in the laboratory and in the wild. However, seeds did not germinate under continuous summer conditions. Radicle emergence in the field was first recorded at the beginning of autumn, when soil temperatures had dropped to c. 15°C in the case of the three lowland populations, and to c. 10°C at the mountain site. Shoot emergence was delayed under natural conditions until late autumn/early winter, when soil temperatures had dropped to c. 10°C in the lowlands and c. 6°C at the mountain site. In the laboratory, a period of cold stratification was required for shoot emergence, and this requirement was more pronounced in the mountain population. Seeds of the mountain population completed embryo development, radicle emergence and shoot emergence at cooler temperatures compared with the lowland populations. These results suggest that germination in A. nemorosa is highly adapted and finely tuned to local climate. We conclude that seeds of A. nemorosa display deep, simple epicotyl, morphophysiogical dormancy, and this is the first report of such dormancy for the genus Anemone. However, the continuous development and growth of embryos from the time of natural dispersal, and the lack of evidence of developmental arrest under natural conditions, suggests that radicles are non-dormant.

scholarly journals Temperature Requirements for Seed Germination of Three Penstemon Species'

HortScience ◽  
1990 ◽  
Vol 25 (2) ◽  
pp. 191-193 ◽  
Author(s):  
Phil S. Allen ◽  
Susan E. Meyer
Keyword(s):  
Seed Germination ◽  
Incubation Temperature ◽  
Marked Decrease ◽  
Rocky Mountain ◽  
Germination Percentage ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Primary Dormancy ◽  
Temperature Requirements ◽  
Seed Propagation

To determine optimum germination temperatures and effective dormancy-breaking procedures, field-grown (1983-85) seeds of `Bandera' Rocky Mountain penstemon (Penstemon strictus Benth), `Cedar' Palmer penstemon (Penstemon palmeri Gray), and firecracker penstemon (Penstemon eatonii Gray) were subjected to various cold stratification and incubation temperature treatments. Increased germination following an 8-week stratification occurred in seed lots containing dormant seeds, but a 2-week stratification generally failed to break dormancy. Older (1983) seeds of `Bandera' and `Cedar' penstemon germinated to full viability without stratification. All species showed a marked decrease in germination percentage above 20C; 15C consistently produced maximum germination after 4 weeks. At 15C, mean times to 90% of total germination were 11, 22, and 29 days for `Bandera', `Cedar', and firecracker penstemon, respectively. Transfer of seeds failing to germinate at warm temperatures (25 and 30C) to 15C and applying 720 μm gibberellic acid (GA3) solution was effective in breaking primary dormancy of firecracker penstemon and secondary dormancy of `Bandera' penstemon. Our findings suggest that incubation below 20C, combined with 8 weeks of stratification or the use of after-ripened seed, may improve seed propagation efforts for these species.

Seed-germination response of Leymus chinensis to cold stratification in a range of temperatures, light and low water potentials under salt and drought stresses

2017 ◽  
Vol 68 (2) ◽  
pp. 188 ◽  
Author(s):  
Jixiang Lin ◽  
Yujie Shi ◽  
Shuang Tao ◽  
Xingyang Yu ◽  
Dafu Yu ◽  
...  
Keyword(s):  
Drought Stress ◽  
Seed Germination ◽  
Drought Tolerance ◽  
Northeast China ◽  
Germination Percentage ◽  
Leymus Chinensis ◽  
Grass Species ◽  
Cold Stratification ◽  
Effective Measure ◽  
Salt And Drought Stresses

Leymus chinensis has important forage value and is considered a useful grass species for grassland restoration in Northeast China. However, little information exists concerning the germination responses of this species to interactions of cold stratification, light, temperature and low water potential caused by salinity and drought. Experiments were conducted in growth chambers, and the results showed that in all conditions of light, temperature and water stresses, the germination percentages of cold-stratified seeds were higher than of non-stratified seeds. Light had an inhibitory effect on germination percentage under both non-saline and salt stress conditions; darkness is beneficial for germination of this species. In addition, seeds germinated much better under alternating temperature regimes than under constant temperatures. Both salt and drought stresses decreased the germination percentage of Leymus chinensis, but the reductions under drought stress were much greater. Moreover, after being transferred to distilled water, most non-germinated seeds under drought stress germinated well, and the total percentage reached that of the non-saline condition level. Therefore, cold stratification is an effective measure to increase seed germination and salt or drought tolerance, especially in darkness. We conclude that Leymus chinensis has definite salt and drought tolerance during the germination stage and it is a promising species for the restoration of deteriorated grassland in Northeast China.

Effects of partial drying on seed germination in the aquatic grasses Zizania palustris L. and Porteresia coarctata (Roxb.) Tateoka

1992 ◽  
Vol 2 (4) ◽  
pp. 199-205 ◽  
Author(s):  
C. D. Aldridge ◽  
R. J. Probert
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Growth Regulators ◽  
Germination Percentage ◽  
Hormonal Status ◽  
Cold Stratification ◽  
Porteresia Coarctata ◽  
Germination Response ◽  
Fold Reduction ◽  
Germination Behaviour

AbstractPartial drying of non-dormant seeds had little effect on germination behaviour compared with undried controls. In contrast, partial drying resulted in a marked increase in the germination response of freshly harvested (dormant) seeds of Z. palustris. Partial drying also resulted in a 100-fold reduction in the concentration of gibberellins (GA4+7) required for maximum germination. Although the concentration range of applied abscisic acid (ABA) that permitted germination was unaltered, partial drying increased the final germination percentage at all concentrations tested. The concentration of ABA above which germination was reduced in freshly harvested (dormant) seeds of Z. palustris was 3.16 × 10−7m compared with 10−4m in fresh (non-dormant) seeds of P. coarctata. Changes in the germination response of Z. palustris seeds to applied growth regulators, following partial drying or cold stratification might be explained by similar changes in hormonal status.

scholarly journals EFFECT OF COLD STRATIFICATION ON SEED GERMINATION OF THE MULTIPURPOSE FRUIT SHRUB, ZIZIPHUS LOTUS (L.) LAM. (RHAMNACEAE)

2020 ◽  
Vol 53 (2) ◽  
pp. 152-159
Author(s):  
A. KHELOUFI ◽  
L. M. MANSOURI ◽  
K. LAIB
Keyword(s):  
Seed Germination ◽  
Root Length ◽  
Germination Percentage ◽  
Seed Morphology ◽  
Cold Stratification ◽  
Shoot Height ◽  
Moist Sand ◽  
Naturally Occurring ◽  
Seedling Length ◽  
Plastic Containers

Shrubs and trees of the genus Ziziphus are a good example of naturally occurring multipurpose plant species with great potential in arid regions. This study was conducted to investigate the effect of cold stratification on seed germination and seedling growth of Ziziphus lotus (L.) Lam. Seeds were subjected to 0, 45, 90 and 120 days of cold stratification at 5°C. We also examined fruit, kernel and seed morphology. For each treatment period, four replicates of 50 seeds were incubated in plastic containers between two layers of moist sand at 15% and under greenhouse conditions for 15-day period. At the end of the experiment, the final germination percentage (FGP), shoot length and root length were assessed. The results clearly indicated that increasing duration of cold stratification improved seed germination. The most effective stratification period was 120 days where Z. lotus recorded 83% of FGP and 16.5 cm of total seedling length. Cold stratification treatments significantly increased shoot height, root length, as well as seedling total length. 120 days stratification treatment resulted in the highest shoot and root length (6.80 cm and 9.75 cm, respectively). An overview on the emergence of Z. lotus seedlings during a 15-day period was also illustrated.

scholarly journals Germination of Fully Developed Corylopsis Seeds Influenced by Harvest Date and Cold Stratification

HortScience ◽  
2018 ◽  
Vol 53 (9) ◽  
pp. 1360-1363 ◽  
Author(s):  
Ji Hee Kim ◽  
Jeung Keun Suh ◽  
Seong-Tak Yoon ◽  
Pablo Jourdan ◽  
Mark S. Roh
Keyword(s):  
Seed Germination ◽  
Germination Percentage ◽  
Harvest Date ◽  
Cold Stratification ◽  
X Ray ◽  
Date Seed ◽  
Seed Maturity ◽  
Internal Structures ◽  
Empty Seeds

Corylopsis seed germination tests were conducted to assess the influence of harvest date (seed maturity) and cold stratification (CS) at 5 °C. Corylopsis gotoana seeds harvested on 12 July, 2 and 22 Aug., 6 and 20 Sept., and 1 and 10 Oct. 2011 were immersed in water for 20 min to separate fully developed seeds (full seeds) from empty seeds by floatation, and by X-ray scanning to identify full from empty seeds (Expt. 1). Immersing seeds in water did not effectively separate full seeds from empty seeds as evaluated by seed germination tests. Seeds harvested on or around 6 Sept. that sank showed translucent X-ray images with fully developed internal structures composed of embryo, cotyledons, and endosperm, and were considered mature. Without CS, >12% seeds harvested on 20 Sept. germinated, regardless of whether seeds were full or empty. Seeds of C. coreana harvested on 5 and 15 Sept., and 5 and 18 Oct. were stored dry at 20 °C until 27 Dec. and germinated after 0, 3, 6, 9, and 12 weeks of CS (Expt. 2). Longer than 6 weeks of CS was required to accelerate and increase the germination of seeds harvested on or after 5 Sept. Germination percentage of full seeds harvested on Oct. 18 was increased to >72% as the duration of CS treatment increased to 12 weeks. In conclusion, fully developed seeds harvested on or after 6 Sept. were considered mature and 6 weeks of CS accelerated germination and increased the germination percentage. Further, dormancy of Corylopsis seeds appears to be shallow since germination occurred without any CS.

scholarly journals Effect of Nitric Oxide on Seed Germination and Dormancy in Empress Trees

2019 ◽  
Vol 29 (3) ◽  
pp. 271-275 ◽  
Author(s):  
Jia Liu ◽  
Tingting Xue ◽  
Yongbao Shen
Keyword(s):  
Nitric Oxide ◽  
Seed Germination ◽  
Sodium Nitroprusside ◽  
Seed Dormancy ◽  
Sodium Tungstate ◽  
Continuous Light ◽  
Germination Percentage ◽  
Cold Stratification ◽  
Endogenous Nitric Oxide ◽  
Tree Seeds

Freshly harvested empress tree (Paulownia elongata) seeds have physiologic dormancy. The aim of this study was to investigate the effects of exogenous and endogenous nitric oxide (NO) on the dormancy and germination of empress tree seeds. After treatment with different concentrations of sodium nitroprusside (an NO-releasing compound) solution, the germination percentage of seeds under 12 h of continuous light was significantly greater. Seed germination percentage was promoted significantly by 10–4 M sodium nitroprusside plus cold stratification compared with seeds treated with cold stratification only. At different hours during imbibition, empress tree seeds treated with 2-(4-carboxyphenyl)-4, 4, 5, 5- tetramethylimidazoline -1-oxyl-3-oxide potassium salt (c-PTIO), NG-nitro-L-arginine methyl ester (L-NAME), and sodium tungstate showed reduced seed germination percentages. During the early hours of imbibition, c-PTIO or sodium tungstate treatment inhibited seed germination significantly. The results showed that both exogenous and endogenous NO can release empress tree seed dormancy. Endogenous NO oxide was involved in dormancy release and germination of seeds during the early stages of imbibition. Wider application of NO may be used for breaking seed dormancy in other species.

scholarly journals Germination Responses to GA3 and Stratification of Threatened Festuca L. Species from Eastern Mediterranean

2006 ◽  
Vol 61 (5-6) ◽  
pp. 372-376 ◽  
Author(s):  
Serap Çelikler ◽  
Gürcan Güleryüz ◽  
Rahmi Bilaloğlu
Keyword(s):  
Seed Germination ◽  
Eastern Mediterranean ◽  
Germination Percentage ◽  
Cold Stratification ◽  
Combined Treatments ◽  
Alpine Belt ◽  
Germination Characteristics ◽  
The Mean ◽  
Different Doses

The seed germination characteristics of three threatened Festuca sp. [F. punctoria Sm., F. cyllenica Boiss. et Heldr. subsp. uluana Markgr.-Dannenb., F. paphlagonica (St.-Yves) Markgr.-Dannenb. subsp. paphlagonica] were investigated. These species are endemic and spread on alpine belt. The study was carried out with wet-cold and dry-cold stratification throughout 15 days, different doses of GA3 (50, 100 and 150 ppm) and hormone-stratification combined treatments, and non-treatment series. We found that the germination rates of three fescue seeds for various treatment series were different. The mean germination percentage of F. cyllenica was higher (80%) than that of F. punctoria and F. paphlagonica which were fairly low (50-60%). Germination rates increased by wet-stratification treatment in F. punctoria and also increased with 100 ppm GA3 application to the seeds of F. paphlagonica. When taken into consideration the germination percentages of all fescue species, the seeds of F. punctoria and F. paphlagonica can be dormant, but the seeds of F. cyllenica are non-dormant.

scholarly journals Dormancy breaking and seed germination of the annual weeds Thlaspi arvense, Descurainia sophia and Malcolmia africana (Brassicaceae)

2014 ◽  
Vol 54 (2) ◽  
pp. 179-187 ◽  
Author(s):  
Hassan Karimmojeni ◽  
Alireza Taab ◽  
Behzad Rashidi ◽  
Amir Hossein Bazrafshan
Keyword(s):  
Seed Germination ◽  
Potassium Nitrate ◽  
Germination Percentage ◽  
Dormancy Breaking ◽  
Natural Conditions ◽  
Winter Cereal ◽  
Soil Burial ◽  
Descurainia Sophia ◽  
Thlaspi Arvense ◽  
Annual Weeds

Abstract In Iran, Descurainia sophia, Malcolmia africana, and Thlaspi arvense are abundantly found as importunate weeds in winter cereal. Understanding the timing of seed germination under natural conditions is crucial for learning how to manage these annual weeds. Therefore, this study was conducted to evaluate the effect of soil burial, dry storage, cold stratification, KNO3, GA3, and scarification on the seed dormancy and germination of these three species. Species had significantly different responses to the treatment. In D. sophia, seeds buried at a depth of 10 cm for 60 days (55%), and seeds dry stored at 20°C for 180 days (45%) showed the highest level of germination. In M. africana, the germination percentage reached 95% when seeds buried at a depth of 1 cm were soaked in a GA3 concentration of 150 ppm. T. arvense had the lowest level of germination compared to the other species. The highest percentage of T. arvense germination was obtained in seeds treated with 150 ppm GA3. Potassium nitrate partly increased germinability in seeds of M. africana, which initially were less dormant than those of T. arvense and D. sophia.

scholarly journals Laser biostimulation for improving seeds germinative capacity and seedlings growth of Prosopis laevigata and Jacaranda mimosifolia

2019 ◽  
Vol 25 (2) ◽  
Author(s):  
María Guadalupe Costilla-Hermosillo ◽  
Martín Ortiz-Morales ◽  
Sofía Loza-Cornejo ◽  
Claudio Frausto-Reyes ◽  
Sami Ali Metwally
Keyword(s):  
Seed Germination ◽  
Germination Percentage ◽  
Timber Species ◽  
Natural Conditions ◽  
Beneficial Effects ◽  
Morphological Variables ◽  
And Control ◽  
Positive Effect ◽  
Jacaranda Mimosifolia ◽  
Germinated Seeds

“Jacaranda” (Jacaranda mimosifolia) and "mezquite” (Prosopis laevigata) are timber species that generally present problems with regard to the germination of their seeds in natural conditions, since they have a very hard and impermeable cover. Different treatments have been applied to improve the germinative response of both species with unfavorable results. This study aimed to know the effect of the pre-sowing laser biostimulation on germination and seedlings growth of these species. The seeds were biostimulated with a He-Ne laser (632 nm, 10 mW). Considering three replications of 50 seeds for each species, five irradiation treatments were applied (30 s, 60 s, 90 s, 120 s, 150 s) and control. The results for mezquite demonstrated that the highest number of germinated seeds (96%) was obtained with the treatments 90 s and 150 s; in contrast, the control seeds showed a lower germination percentage (16%). Additionally, the 30 s treatment produced a positive effect on the growth of the root, and it was different (p < 0.05) to the remaining treatments and the control. For Jacaranda, there were significant statistical differences (p < 0.05) between the control and the different treatments. 29% of seed germination occurs without any treatment. However, for 90 s and 120 s, germination is induced in a relatively high percent (97%-99%). For both species, the best treatment was 120 s, since higher values were recorded for all the morphological variables. It is concluded that laser biostimulation can produce beneficial effects on the germination of seeds and seedling growth and it could contribute to the propagation and conservation of these species.

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