scholarly journals Effects of alternating temperature and cold stratification on germination of three halophyte species

2021 ◽  
Vol 46 (4) ◽  
pp. 405-406
Author(s):  
Miho NAGATA ◽  
Kohei OKA
Keyword(s):  
Cold Stratification ◽  
Alternating Temperature

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 Dry after-ripening, light, cold stratification and temperature effects on seed germination of Primula poissonii from Yunnan, China

2019 ◽  
Author(s):  
Deli Peng ◽  
Xiaojian Hu ◽  
Hang Sun ◽  
Zhimin Li
Keyword(s):  
Seed Germination ◽  
Temperature Gradient ◽  
Temperature Effects ◽  
Southwest China ◽  
Alpine Region ◽  
Wild Plant ◽  
Cold Stratification ◽  
Light Requirement ◽  
Alternating Temperature ◽  
Improve Seed Germination

Primula poissonii, an attractive wild plant growing in the subalpine/alpine region of southwest China, has low seed germination in cultivation. This study attempted to improve seed germination by testing the effect of several treatments including dry after-ripening (DAR), light, cold stratification (CS) and temperature gradient treatments. DAR increased germination at 15/5 and 25/15°C, as compared with fresh seeds. DAR seeds germinated significantly better (> 80%) at higher temperatures (20-28°C) than at lower (10°C, < 20%; 15°C, < 30%) and extreme high temperatures (30°C, < 55%; 32°C, 0%). Incubation at alternating temperature (25/15°C) did not significantly improve germination; whereas at 15/5°C germination increased significantly, compared with the corresponding constant temperature (20 and 10°C, respectively). DAR seeds had a strict light requirement at all temperatures. As DAR and CS are sufficient to break seed dormancy, the seeds of P. poissonii appear to have non-deep PD. For non-dormant cold-stratified seeds, the estimated Tb and thermal time (θ50) were 2.3°C and 74.1°Cd, respectively.

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.

scholarly journals Optimal germination conditions for monitoring seed viability in wild populations of fescues

2021 ◽  
Vol 19 (3) ◽  
pp. e0804-e0804
Author(s):  
Pablo Vivanco ◽  
Keyword(s):  
Gibberellic Acid ◽  
Seed Dormancy ◽  
Seed Viability ◽  
Cold Stratification ◽  
Wild Populations ◽  
Negative Effect ◽  
Species Area ◽  
Northwestern Spain ◽  
Alternating Temperature ◽  
Germination Requirements

Aim of study: Germination assays are vital in the management of material preserved in germplasm banks. The rules published by the International Seed Testing Association (ISTA) are generally those followed in such assays. In wild species, seed dormancy and inter-population variability increase the difficulty in estimating seed viability. The aim of the present work was to determine the germination requirements of the seeds from different wild populations of pasture grasses species. Area of study: Northwestern Spain Material and methods: Seeds from eight wild populations of different species of Festuca, all from northwestern Spain, were studied. Germination assays were performed under constant and alternating temperature conditions. Treatments for removing seed dormancy (cold stratification and gibberellic acid application) were also applied. A full parametric time-to event model was used for data analysis. Main results: In general, the optimum environmental temperature for germination was around 15°C for the populations of Festuca group ovina, F. gr. rubra and F. gigantea; temperatures of 20-30ºC had a negative effect. All the examined populations, except that of tall fescue (Lolium arundinaceum), showed non-deep physiological dormancy at suboptimal germination temperatures, but this was breakable by the application of gibberellic acid and by cold stratification. Research highlights: There are clear inter- and intra-specific differences in germination requirements that might be associated with place of origin. The ISTA germination assay recommendations for wild members of fescues may not be the most appropriate.

scholarly journals Practical Methods for Breaking Seed Dormancy in a Wild Ornamental Tulip Species Tulipa thianschanica Regel

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1765
Author(s):  
Wei Zhang ◽  
Lian-Wei Qu ◽  
Jun Zhao ◽  
Li Xue ◽  
Han-Ping Dai ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Combined Treatment ◽  
Individual Treatment ◽  
Cold Stratification ◽  
Slight Effect ◽  
Sowing Depth ◽  
Physiological Dormancy ◽  
Commercial Breeding ◽  
Breaking Seed Dormancy

The innate physiological dormancy of Tulipa thianschanica seeds ensures its survival and regeneration in the natural environment. However, the low percentage of germination restricts the establishment of its population and commercial breeding. To develop effective ways to break dormancy and improve germination, some important factors of seed germination of T. thianschanica were tested, including temperature, gibberellin (GA3) and/or kinetin (KT), cold stratification and sowing depth. The percentage of germination was as high as 80.7% at a constant temperature of 4 °C, followed by 55.6% at a fluctuating temperature of 4/16 °C, and almost no seeds germinated at 16 °C, 20 °C and 16/20 °C. Treatment with exogenous GA3 significantly improved the germination of seeds, but KT had a slight effect on the germination of T. thianschanica seeds. The combined treatment of GA3 and KT was more effective at enhancing seed germination than any individual treatment, and the optimal hormone concentration for the germination of T. thianschanica seeds was 100 mg/L GA3 + 10 mg/L KT. In addition, it took at least 20 days of cold stratification to break the seed dormancy of T. thianschanica. The emergence of T. thianschanica seedlings was the highest with 82.4% at a sowing depth of 1.5 cm, and it decreased significantly at a depth of >3.0 cm. This study provides information on methods to break dormancy and promote the germination of T. thianschanica seeds.

Taiwanese montaneSambucus chinensisseeds require warm stratification, contrasting with other congeneric temperate members

2014 ◽  
Vol 24 (3) ◽  
pp. 217-228 ◽  
Author(s):  
Shun-Ying Chen ◽  
Ching-Te Chien ◽  
Siti N. Hidayati ◽  
Jeffrey L. Walck
Keyword(s):  
North America ◽  
Cold Stratification ◽  
Cold Temperatures ◽  
Tropical Regions ◽  
Morphophysiological Dormancy ◽  
Primary Mechanism ◽  
Northern Latitudes ◽  
Northern Hemispheric ◽  
Response To Temperature ◽  
Seed Characteristics

AbstractMany temperate plant genera, likeSambucus, have species with range disjunctions among North America, Europe and/or Asia. Cold stratification (sometimes in combination with warm stratification) is the primary mechanism to break seed dormancy in these species. For some of these genera showing Northern Hemispheric disjunctions, members also occur in subtropical or tropical regions, mostly confined to higher elevations where climate and vegetation differ from those in northern latitudes. We made two hypotheses concerning germination for the subtropical TaiwaneseSambucus chinensis: (1) seeds from populations exposed to warm temperatures would require warm stratification, and (2) seeds from populations exposed to cold temperatures need cold stratification. We investigated the germination (including embryo growth) of non-stratified seeds over a range of temperatures and tested the effects of cold stratification and of gibberellins GA3and GA4on germination. The amount and timing of germination among populations varied substantially in response to temperature treatments. Seeds from all populations of this species required warm temperatures for dormancy break and germination, regardless of environmental conditions. As such, the majority of seeds had non-deep simple morphophysiological dormancy, which, until now, has not been reported in any members ofSambucus. The seed characteristics of the subtropicalS. chinensisare different from those of temperate members of the genus in which cold stratification is the predominate treatment to overcome dormancy.

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