Morphophysiological dormancy in seeds of six endemic lobelioid shrubs (Campanulaceae) from the montane zone in Hawaii

2005 ◽  
Vol 83 (12) ◽  
pp. 1630-1637 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin ◽  
Alvin Yoshinaga
Keyword(s):  
Incubation Period ◽  
Seasonal Temperature ◽  
Dormancy Breaking ◽  
Light Requirement ◽  
Temperature Variations ◽  
Morphophysiological Dormancy ◽  
Temperature Regimes ◽  
Physiological Dormancy ◽  
Montane Zone ◽  
Germination Requirements

The purpose of this study was to investigate seed dormancy breaking and germination requirements of six woody Hawaiian endemic lobelioids (Campanulaceae). Seeds of all species had underdeveloped, physiologically dormant embryos and thus morphophysiological dormancy. Fresh seeds of Clermontia pyrularia Hillebr. and Trematolobelia macrostachys (Hook. & Arnott) A. Zahlbr. did not germinate during 4 weeks of incubation in light at 15/6, 20/10, or 25/15 °C, whereas those of Clermontia fauriei H. Lev., Clermontia hawaiiensis (Hillebr.) Rock, Clermontia kakeana Meyen, and Cyanea angustifolia (Cham.) Hillebr. germinated to 61%–85% but only at 25/15 °C. Since seeds of the latter four species eventually germinated to 84%–100% when incubated for 12–36 weeks at the three temperature regimes, fresh seeds had conditional dormancy; the physiological component of morphophysiological dormancy was nondeep. Seeds of Trematolobelia macrostachys also came out of dormancy (and germinated to 90%) during 18 weeks of incubation at each of the three temperatures regimes, whereas those of Clermontia pyrularia did so only at 15/6 °C. Simulated seasonal temperature variations did not promote dormancy break and germination in any species except Clermontia pyrularia , in which a 12-week incubation period at 25/15 °C resulted in 90% germination after seeds were moved to 20/10 °C. Seeds of all species had an absolute light requirement for germination except those of Clermontia pyrularia, which germinated to 48% in darkness. Since seeds of the six species only require high temperatures for embryo growth and the breaking of physiological dormancy, they have nondeep simple morphophysiological dormancy.

Intermediate morphophysiological dormancy allows for life-cycle diversity in the annual weed, Turgenia latifolia (Apiaceae)

2014 ◽  
Vol 62 (8) ◽  
pp. 630 ◽  
Author(s):  
Miregul Nurulla ◽  
Carol C. Baskin ◽  
Juan J. Lu ◽  
Dun Y. Tan ◽  
Jerry M. Baskin
Keyword(s):  
Life Cycle ◽  
Low Temperatures ◽  
Western China ◽  
Intermediate Complex ◽  
Dormancy Breaking ◽  
Morphophysiological Dormancy ◽  
Temperature Regimes ◽  
Germination Phenology ◽  
Physiological Dormancy ◽  
Winter Annual

Our aim was to determine the seed dormancy-breaking requirements and type of life cycle of Turgenia latifolia in north-western China. At dispersal in July, only 0–9% of the seeds germinated at 5/2°C, 15/2°C, 20/10°C and 25/15°C; thus, 91% of the seeds exhibited physiological dormancy (PD) and 9% were non-dormant. Also, the embryo was underdeveloped and embryo length : seed length ratio increased from 0.38 in fresh seeds to 0.79 at germination. Seeds buried in dry soil at the four temperature regimes for 12 weeks germinated to ≥50% when tested in darkness at 5/2°C, and those buried at 15/2°C and 20/10°C germinated to ≥50% when tested at 15/2°C. Seeds have intermediate complex morphophysiological dormancy (MPD). PD was broken at high and/or low temperatures, but embryo growth was completed only at low temperatures; gibberellic acid (GA3) promoted germination. Seeds buried under natural conditions during summer germinated to ~70% and ~55% at 5/2°C and 15/2°C, respectively, in darkness in autumn. In a germination-phenology study, cumulative germination was ~20% and ~80% in autumn and spring, respectively. Intermediate complex MPD allows the species to behave as a winter annual and as a short-lived summer annual.

Non-deep simple morphophysiological dormancy in seeds of the rare Alpinia galanga: a first report for Zingiberaceae

2016 ◽  
Vol 26 (2) ◽  
pp. 165-170 ◽  
Author(s):  
R.G. Baradwaj ◽  
M.V. Rao ◽  
Carol C. Baskin ◽  
T. Senthil Kumar
Keyword(s):  
Temperature Regime ◽  
Dormancy Breaking ◽  
Alpinia Galanga ◽  
First Report ◽  
Morphophysiological Dormancy ◽  
Temperature Regimes ◽  
Physiological Dormancy ◽  
Minimum Number ◽  
The Ideal

AbstractLittle information is available on seed dormancy of members of the Zingiberales and especially the Zingiberaceae. Our aim was to investigate the dormancy breaking and germination requirements of Alpinia galanga in vitro with a minimum number of seeds, using the move-along experiment. The mass of imbibed seeds increased by 17.5% in 1 d, showing that seeds were water permeable. The best germination in the move-along experiment (86.7%) was obtained when seeds were exposed to the sequence of temperature regimes that began with winter (20/10°C), and seeds began to germinate after 6 weeks at this temperature regime. Seeds dry stored for 4 months and then incubated at the sequence of temperature regimes that began with summer (30/20°C) started germinating in the sixth week at this temperature regime and had germinated to 93.3% after 18 weeks. Seeds kept dry for 4 months and then treated with 50 mg l−1 gibberellic acid (GA3) began to germinate at 30/20°C after 2 weeks. Control seeds incubated continuously at 20/10, 25/15 or 30/20°C germinated to 80.6, 77.8 and 60.0%, respectively. When incubated at 15, 20, 25 or 30°C, the ideal temperature for embryo growth was 20°C. Since GA3 and dry storage can break non-deep physiological dormancy and embryos grew during warm stratification, seeds of A. galanga have non-deep simple morphophysiological dormancy (MPD). This is the first report of non-deep simple MPD in the Zingiberaceae.

Non-deep simple morphophysiological dormancy in seeds of Cheirodendron trigynum (Araliaceae) from the montane zone of Hawaii

2015 ◽  
Vol 25 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin ◽  
Alvin Yoshinaga
Keyword(s):  
Low Temperature ◽  
Woody Species ◽  
First Report ◽  
Morphophysiological Dormancy ◽  
Temperature Regimes ◽  
Physiological Dormancy ◽  
Montane Zone ◽  
Radicle Emergence ◽  
Shoot Emergence

AbstractThe Araliaceae is known to have seeds with underdeveloped embryos that must grow prior to radicle emergence, and thus they have morphological (MD) or morphophysiological (MPD) dormancy. Araliaceae is one of about 15 families with woody species in the tropical montane zone, and in Hawaii 15 species occur in the montane. Our purpose was to determine if seeds of the Hawaiian Araliaceae species Cheirodendron trigynum subsp. trigynum have MD or MPD and, if MPD, what level. In a move-along experiment, some seeds were incubated continuously at 15/6, 20/10 or 25/15°C, while others were moved sequentially from low to high or from high to low temperature regimes. Germination percentages and embryo growth were monitored. Also, the effects of cold and warm stratification on dormancy break were determined. Seeds had physiological dormancy (PD) in addition to small embryos that grew prior to germination, and thus MPD. PD was broken slowly ( ≥ 12 weeks), after which embryos grew rapidly, followed by root and shoot emergence. Embryos grew at temperatures suitable for warm stratification; thus, seeds have Type 1 non-deep simple MPD; the dormancy formula is C1bBb. Seeds from Oahu germinated to 94–100% at 15/6, 20/10 and 25/15°C, while those from the Big Island germinated to high percentages only at 15/6 and 20/10°C. Temperature shifts improved germination of seeds from the Big Island, and movement from either low to high or from high to low temperature regimes was effective in promoting germination. This is the first report of non-deep simple MPD in the Araliaceae.

Dormancy-breaking and germination requirements for seeds of Diervilla lonicera (Caprifoliaceae), a species with underdeveloped linear embryos

2000 ◽  
Vol 78 (9) ◽  
pp. 1199-1205 ◽  
Author(s):  
Siti N Hidayati ◽  
Jerry M Baskin ◽  
Carol C Baskin
Keyword(s):  
Seed Dormancy ◽  
Constant Darkness ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Morphophysiological Dormancy ◽  
Germination Phenology ◽  
Physiological Dormancy ◽  
Temperature Controlled ◽  
Germination Requirements ◽  
Morphological Dormancy

Dormancy-breaking requirements and type of dormancy were determined for seeds of Diervilla lonicera Mill. Seeds have an underdeveloped linear embryo that is about 35% of the length of the seed at maturity. Embryos (in intact seeds) grew at 25:15°C but not at 5°C. Up to 85% of the freshly matured seeds had morphological dormancy (MD), and thus, they germinated within about 30 days on a moist substrate in light at 30:15°C; a maximum of 3% of the seeds germinated in constant darkness. The other portion of fresh seeds had nondeep simple morphophysiological dormancy (MPD) and required a period of warm stratification or treatment with GA3 to break dormancy. These seeds also required light to germinate. In contrast, cold stratification induced dormancy, and dry storage for up to 1 year did not effectively break dormancy. Seeds with MD germinated to significantly higher percentages on soil than on filter paper or on sand. Seeds sown on soil in a non-temperature-controlled greenhouse in mid-November germinated mostly in late May, whereas those sown in mid-April germinated in early May. Apparently, embryos of November-sown seeds were induced into physiological dormancy during winter. Thus, seeds had MPD in spring and needed several weeks of warm temperatures for dormancy break, embryo growth, and germination. This is the first report on seed dormancy in the genus Diervilla.Key words: embryo growth, germination phenology, Diervilla lonicera, morphological seed dormancy, morphophysiological seed dormancy, underdeveloped linear embryo.

scholarly journals Non-Deep Physiological Dormancy in Seed and Germination Requirements of Lysimachia coreana Nakai

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 490
Author(s):  
Saeng Geul Baek ◽  
Jin Hyun Im ◽  
Myeong Ja Kwak ◽  
Cho Hee Park ◽  
Mi Hyun Lee ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Germination Rate ◽  
Seed Viability ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Viability Test ◽  
Physiological Dormancy ◽  
Different Temperatures ◽  
Germination Requirements

This study aimed to determine the type of seed dormancy and to identify a suitable method of dormancy-breaking for an efficient seed viability test of Lysimachia coreana Nakai. To confirm the effect of gibberellic acid (GA3) on seed germination at different temperatures, germination tests were conducted at 5, 15, 20, 25, 20/10, and 25/15 °C (12/12 h, light/dark), using 1% agar with 100, 250, and 500 mg·L−1 GA3. Seeds were also stratified at 5 and 25/15 °C for 6 and 9 weeks, respectively, and then germinated at the same temperature. Seeds treated with GA3 demonstrated an increased germination rate (GR) at all temperatures except 5 °C. The highest GR was 82.0% at 25/15 °C and 250 mg·L−1 GA3 (4.8 times higher than the control (14.0%)). Additionally, GR increased after cold stratification, whereas seeds did not germinate after warm stratification at all temperatures. After cold stratification, the highest GR was 56.0% at 25/15 °C, which was lower than the GR observed after GA3 treatment. We hypothesized that L. coreana seeds have a non-deep physiological dormancy and concluded that 250 mg·L−1 GA3 treatment is more effective than cold stratification (9 weeks) for L. coreana seed-dormancy-breaking.

Morphological and physiological dormancy in seeds of Aegopodium podagraria (Apiaceae) broken successively during cold stratification

2009 ◽  
Vol 19 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Filip Vandelook ◽  
Nele Bolle ◽  
Jozef A. Van Assche
Keyword(s):  
Low Temperature ◽  
Seedling Emergence ◽  
Early Spring ◽  
Temperate Climate ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Morphophysiological Dormancy ◽  
Temperature Requirement ◽  
Physiological Dormancy ◽  
Chilling Period

AbstractA low-temperature requirement for dormancy break has been observed frequently in temperate-climate Apiaceae species, resulting in spring emergence of seedlings. A series of experiments was performed to identify dormancy-breaking requirements of Aegopodium podagraria, a nitrophilous perennial growing mainly in mildly shaded places. In natural conditions, the embryos in seeds of A. podagraria grow in early winter. Seedlings were first observed in early spring and seedling emergence peaked in March and April. Experiments using temperature-controlled incubators revealed that embryos in seeds of A. podagraria grow only at low temperatures (5°C), irrespective of a pretreatment at higher temperatures. Seeds did not germinate immediately after embryo growth was completed, instead an additional cold stratification period was required to break dormancy completely. Once dormancy was broken, seeds germinated at a range of temperatures. Addition of gibberellic acid (GA3) had a positive effect on embryo growth in seeds incubated at 10°C and at 23°C, but it did not promote germination. Since seeds of A. podagraria have a low-temperature requirement for embryo growth and require an additional chilling period after completion of embryo growth, they exhibit characteristics of deep complex morphophysiological dormancy.

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 in Camellia sinensis L. (Theaceae): effects of cold-stratification and exogenous gibberellic acid application on germination

Botany ◽  
2017 ◽  
Vol 95 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Danping Song ◽  
Ganesh K. Jaganathan ◽  
Yingying Han ◽  
Baolin Liu
Keyword(s):  
Gibberellic Acid ◽  
Camellia Sinensis ◽  
Summer Temperature ◽  
Cold Stratification ◽  
Morphophysiological Dormancy ◽  
Temperature Regimes ◽  
Physiological Dormancy ◽  
Radicle Emergence ◽  
Persistent Seed Bank ◽  
Natural Dispersal

There are several different opinions regarding dormancy in tea (Camellia sinensis L.), but there is no strong evidence available to conclude whether or not these seeds are dormant. Freshly matured tea seeds collected from Hangzhou, China, at the natural dispersal time did not germinate in light at daily alternative temperature regimes of 10/15, 15/20, 20/25, or 25/35 °C, or at a constant temperature of 25 °C. Seeds were permeable to water and the embryos did not grow prior to radicle emergence, thus, the seeds have no physical, morphological, or morphophysiological dormancy. When cold-stratified at 4 °C for 1, 2, and 3 months, 64%, 88%, and 93% of the seeds germinated, respectively. Intact fresh seeds failed to germinate after treatment with 0, 10, 500, and 1000 ppm GA3, whereas 3%, 4%, 61%, and 86% of cracked seeds germinated, respectively. Thus, the seeds have nondeep and intermediate physiological dormancy. Seeds cold-stratified for 2 months that were buried at soil depths of 0, 1, and 5 cm in pots showed that seeds at 1 cm depth established significantly higher number of seedlings (P < 0.05) than at other two depths. Because tea seeds are susceptible to summer temperature drying, these seeds do not establish a persistent seed bank.

A new type of non-deep physiological dormancy: evidence from three annual Asteraceae species in the cold deserts of Central Asia

2014 ◽  
Vol 24 (4) ◽  
pp. 301-314 ◽  
Author(s):  
Mihray Nur ◽  
Carol C. Baskin ◽  
Juan J. Lu ◽  
Dun Y. Tan ◽  
Jerry M. Baskin
Keyword(s):  
Central Asia ◽  
Mechanical Resistance ◽  
Dormancy Breaking ◽  
Germination Phenology ◽  
Physiological Dormancy ◽  
Temperature Requirements ◽  
Dry Conditions ◽  
New Type ◽  
Late Stages ◽  
Germination Requirements

AbstractAlthough Asteraceae species are important in the cold deserts of Central Asia, little is known about their seed dormancy and germination. We determined dormancy breaking and germination requirements of three annual Asteraceae, Echinops gmelinii, Epilasia acrolasia and Koelpinia linearis. Achenes (seeds) were tested for germination in light and in darkness over a range of alternating temperatures after various periods of burial outdoors and of dry storage. Germination phenology was monitored for seeds sown in irrigated and non-irrigated sand, and temperature requirements for dormancy break were determined under wet and dry conditions. Effects of pericarp and phyllaries on germination of E. acrolasia and E. gmelinii, respectively, were determined. Low percentages of 20-day-old seeds of E. acrolasia and K. linearis were non-dormant and germinated to low percentages over the range of temperatures, whereas all seeds of E. gmelinii were dormant. As seeds of the three species afterripened, they germinated over the range of temperatures. Whether seeds germinated in autumn or spring depended on the amount of sand moisture. Mechanical resistance of the pericarp and phyllaries reduced germination of E. acrolasia and E. gmelinii, respectively. Temperature requirements for germination as seeds come out of dormancy do not correspond to any of the known five types of non-deep physiological dormancy (PD). Thus, a sixth type is recognized in which germination occurs over the same range of temperatures in the early and late stages of dormancy break. Type 6 allows seeds to germinate at high or at low temperatures, whenever sand moisture is non-limiting.

Dormancy-breaking and germination requirements of seeds of the Hawaiian endemic Dianella sandwicensis (Xanthorrhoeaceae)

2018 ◽  
Vol 66 (3) ◽  
pp. 213 ◽  
Author(s):  
Dustin Wolkis ◽  
Carol C. Baskin ◽  
Jerry M. Baskin
Keyword(s):  
Plant Species ◽  
Early Summer ◽  
Wild Plant ◽  
Dormancy Breaking ◽  
Seed Length ◽  
Morphophysiological Dormancy ◽  
Wild Plant Species ◽  
Temperature Requirements ◽  
Embryo Length ◽  
Germination Requirements

One problem with including some wild plant species in restoration projects is that seeds are dormant and fail to germinate. Thus, information on the dormancy-breaking and germination requirements facilitates propagation of species, such as the Hawaiian endemic Dianella sandwicensis Hook. & Arn., for conservation. In seeds of this species the embryo is shorter than the endosperm, and seeds sown in early summer in Hawai‘i did not germinate until autumn. Thus, we hypothesised that seeds have morphophysiological dormancy (MPD) and that germination is promoted by low (autumn) temperatures. Studies on embryo growth and the temperature requirements for dormancy-break and germination were conducted on seeds of D. sandwicensis collected on three Hawaiian Islands. Prior to germination the embryo length : seed length ratio increased 16.3 to 17.6%; thus, seeds have MPD. Since both embryo growth and germination occurred at 25/15°C, seeds have a simple level of MPD. Seeds germinated to 90–100% at both 20/10 and 25/15°C, but germination was faster at 20/10°C. However, seeds incubated for 12 weeks at 25/15°C then moved to 20/10°C reached 100% germination as rapidly as seeds kept at 20/10°C. Our results show that exposure of seeds to relatively cool autumn (20/10°C) conditions facilitates propagation of this species from seeds.

Sign in / Sign up

Export Citation Format

Share Document