Seed quality and germination characteristics of tamarack in northwestern Ontario

1986 ◽  
Vol 16 (3) ◽  
pp. 680-683 ◽  
Author(s):  
Robert E. Farmer Jr. ◽  
Ronald W. Reinholt
Keyword(s):  
Seed Quality ◽  
Northwestern Ontario ◽  
Temperature Regimes ◽  
Germination Characteristics ◽  
Before And After ◽  
Alternating Temperature ◽  
Individual Trees ◽  
Incubation Temperatures

Tamarack seed from provenances in northwestern Ontario were incubated in light and dark under a range of alternating temperature regimes (5–15, 10–20, and 20–30 °C) before and after 33 days stratification. Unstratified sound seed germinated completely in light at all incubation temperatures. Partial germination of unstratified seed took place in the dark at 20–30 °C, but stratification was required for dark germination at lower temperatures. Wide variation in dark germination was noted among seed lots from individual trees, but stand and provenance differences were nonsignificant. Much of the variation in seed quality among tree lots was related to differences in the degree of embryo failure.

Reciprocal Common Garden Studies of the Germination of Seeds of Big Sagebrush (Artemisia tridentata)

Weed Science ◽  
1989 ◽  
Vol 37 (3) ◽  
pp. 319-325 ◽  
Author(s):  
James A. Young ◽  
Raymond A. Evans
Keyword(s):  
Plant Communities ◽  
Common Garden ◽  
Moisture Stress ◽  
Freezing Temperature ◽  
Big Sagebrush ◽  
Temperature Regimes ◽  
Germination Characteristics ◽  
Alternating Temperature ◽  
Incubation Temperatures

Experiments were conducted to compare the influence of production site and seed source on the germination of big sagebrush seeds in relation to incubation temperatures. Seeds of big sagebrush were collected from five plant communities located on the margin of the Carson Desert in western Nevada. Seedlings were grown from the seeds and transplanted back to the sites of collection in reciprocal gardens. Seeds from 1-yr-old gardens were tested for germination at a constant 15 C for three consecutive years. The greater quantity of seeds produced by 2- and 3-yr-old gardens were tested at 55 constant or alternating temperature regimes. Seeds of big sagebrush produced in reciprocal gardens had lower germination than seeds collected from native stands at the same locations. The reduced germination disappeared as the reciprocally transplanted plants grew older and larger, but seeds from these plants did not reach the same levels of germination as those collected from native stands at the same location. Moisture stress and/or freezing temperature conditions during flowering may have directly influenced the quality of seeds produced or interacted with the inherent genotypes of big sagebrush to trigger seed production of variable quality in relation to germination characteristics.

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 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.

scholarly journals Durum Wheat Breeding in the Mediterranean Region: Current Status and Future Prospects

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 432 ◽  
Author(s):  
Ioannis N. Xynias ◽  
Ioannis Mylonas ◽  
Evangelos G. Korpetis ◽  
Elissavet Ninou ◽  
Aphrodite Tsaballa ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Mediterranean Region ◽  
Seed Quality ◽  
Green Revolution ◽  
Historical Review ◽  
Wheat Breeding ◽  
Molecular Techniques ◽  
Current Status ◽  
Before And After ◽  
The Mediterranean

This brief historical review focuses on durum wheat domestication and breeding in the Mediterranean region. Important milestones in durum wheat breeding programs across the countries of the Mediterranean basin before and after the Green Revolution are discussed. Additionally, the main achievements of the classical breeding methodology are presented using a comparison of old and new cultivars. Furthermore, current breeding goals and challenges are analyzed. An overview of classical breeding methods in combination with current molecular techniques and tools for cultivar development is presented. Important issues of seed quality are outlined, focusing on protein and characteristics that affect human health and are connected with the consumption of wheat end-products.

Prediction of Frost Hardiness in Douglas Fir Seedlings by Measuring Electrical Impedance in Stems at Different Frequencies

1973 ◽  
Vol 3 (2) ◽  
pp. 256-264 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Survival Data ◽  
Electrical Impedance ◽  
Douglas Fir ◽  
Frost Hardiness ◽  
Impedance Measurements ◽  
Temperature Regimes ◽  
Before And After ◽  
Post Test ◽  
Different Levels ◽  
Short Days

Frost hardiness of Douglas fir (Pseudotsugamenziesii Mirb. Franco.) plants was assessed by a range of freezing tests in three experiments. In experiments 1 and 2 plants were grown in different temperature regimes, under short days, for 8 weeks to induce different levels of frost hardiness. In experiment 3, plants remained in the open and were sampled on 21 occasions through one year.Comparison of stem impedance measurements made at 1 kHz, 4.5 kHz, and 1 MHz, before and after freezing tests in experiments 1 and 2, indicated survival of individual plants was well predicted by post test measurements. The postfreezing test 1 kHz/1 MHz ratio distinguished between dead and surviving plants with the smallest number of measurements. Both this ratio and 4.5 kHz impedance provided similar conclusions about treatment effects, which agreed satisfactorily with conclusions from survival data. Impedance ratios of 1 kHz/1 MHz measured in stems after freezing tests accurately predicted survival in experiment 3. Seasonal changes in ratio, determined after freezing to a particular temperature, paralleled seasonal change in plant frost hardiness and was significantly correlated with exposure to cold during 14 days prior to measurement.

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 Physical purity and germination of sugarcane seeds (caryopses) (Saccharum spp.)

2010 ◽  
Vol 32 (2) ◽  
pp. 140-145 ◽  
Author(s):  
Juliana Terezinha Caieiro ◽  
Maristela Panobianco ◽  
João Carlos Bespalhok Filho ◽  
Osvaldo de Castro Ohlson
Keyword(s):  
Plant Breeding ◽  
Seed Viability ◽  
Germination Test ◽  
Paper Substrate ◽  
Breeding Programs ◽  
Saccharum Spp ◽  
Test Study ◽  
Alternating Temperature ◽  
Incubation Temperatures ◽  
Favorable Conditions

Plant breeding is generally done through sexual reproduction even when the species is propagated asexually for commercial exploitation, as for example, in sugarcane. Therefore, the development of procedures to evaluate sugarcane seed viability is important for plant breeding programs. The objective of this research was to develop a methodology for analyzing the viability of sugarcane seeds (Saccharum spp.). Three crosses were used, two biparental crosses and one polycross. For the germination test study, two substrates (paper and sand) and three constant incubation temperatures (25 ºC, 30 ºC and 35 ºC), in the presence of constant light and also an alternating temperatures (20-30 ºC), with 8 hours light (30 ºC) and 16 hours darkness (20 ºC), were studied. Seedlings were evaluated every five days. The results demonstrated that temperature affected sugarcane seed germination with the most favorable conditions being the alternating temperature (20-30 ºC) and the constant temperature of 30 ºC on a paper substrate.

Dormancy and Germination of Seed of Eight Populations of Themeda australis

1982 ◽  
Vol 30 (4) ◽  
pp. 373 ◽  
Author(s):  
RH Groves ◽  
MW Hagon ◽  
PS Ramakrishnan
Keyword(s):  
Population Stratification ◽  
Physiological Adaptation ◽  
Dormant Seed ◽  
Seed Formation ◽  
Fresh Seed ◽  
Temperature Regimes ◽  
Germination Characteristics ◽  
Moisture Regimes ◽  
Different Populations ◽  
Climatic Characteristics

Seed of eight populations of Themeda australis (R.Br.) Stapf from sites nith the widest range of climates in Australia and Papua New Guinea (P.N.G.) was tested for its dormancy status and germination responses to different temperature and moisture regimes. The populations were from Lae. P.N.G.. Katherine. N.T.. Mundubbera. Qld. Alice Springs. N.T.. Tantangara. N.S.W.. Adelaide Hills. S.A.. Bunbury, W.A. and Hobart. Tas. Dormancy of fresh seed was negligible in Lae and Mundubbera populations. considerable in the Alice Springs population and intermediate in populations from Katherine and all temperate sites. Addition of gibberellic acid hastened the release from dormancy of seed from Katherine and Bunbury. Exposure of plants to three different temperature regimes during seed formation had an effect on dormancy of the Katherine population. Stratification at 4°C and high alternating daily temperatures (45 20°C) hastened the loss of dormancy of fresh seeds of some populations. Germination of non-dormant seed of the different populations was relatively unaffected b) temperatures between 20 and 40°C. Germination of the Alice Springs population was the most sensitive to increasing water stress and that from Lae the least sensitive. Radicle elongation of seedlings from Alice Springs was significantly greater than that of most other populations at a water potential of - I .0 MPa. The differences reported for seed dormancy and germination characteristics of T. australis populations do not reflect a strong physiological adaptation to the climatic characteristics of the sites from which they were collected.

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