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.

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.

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.

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.

Sensitivity cycling and its ecological role in seeds with physical dormancy

2009 ◽  
Vol 19 (1) ◽  
pp. 3-13 ◽  
Author(s):  
K.M.G. Gehan Jayasuriya ◽  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Life Cycle ◽  
Environmental Conditions ◽  
Common Phenomenon ◽  
Ecological Role ◽  
Dormancy Breaking ◽  
Physical Dormancy ◽  
Physiological Dormancy ◽  
Seed Coats

AbstractCycling of physically dormant (PY) seeds between states insensitive and sensitive to dormancy-breaking factors in the environment has recently been demonstrated inFabaceaeandConvolvulaceae, and it may be a common phenomenon in seeds with water-impermeable seed coats. In contrast to seeds of many species with physiological dormancy (PD), those with PY cannot cycle between dormancy and non-dormancy (ND). In this paper, we evaluate the role of sensitivity cycling in controlling the timing of germination of seeds with PY in nature, and show that sensitivity cycling in seeds with PY serves the same ecological role as dormancy cycling in seeds with PD. Thus, sensitivity cycling in seeds with PY ensures that germination in nature occurs only at (a) time(s) of the year when environmental conditions for growth are, and are likely to remain, suitable long enough for the plant to complete its life cycle or to form a perennating structure. Further, we describe the experimental procedures necessary to determine whether sensitivity cycling is occurring, and discuss briefly the possible relevance of sensitivity cycling to dormancy classification.

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.

Multiple environmental signals required for embryo growth and germination of seeds of Selinum carvifolia (L.) L. and Angelica sylvestris L. (Apiaceae)

2007 ◽  
Vol 17 (4) ◽  
pp. 283-291 ◽  
Author(s):  
Filip Vandelook ◽  
Nele Bolle ◽  
Jozef A. Van Assche
Keyword(s):  
Seedling Emergence ◽  
Early Spring ◽  
Time Interval ◽  
Short Time Interval ◽  
Cold Stratification ◽  
Dormancy Breaking ◽  
Environmental Signals ◽  
Morphophysiological Dormancy ◽  
Physiological Dormancy ◽  
Short Time

AbstractGermination and dormancy breaking requirements were studied in Selinum carvifolia (L.) L. and Angelica sylvestris L. (Apiaceae). Seeds of these two species have an underdeveloped embryo and are morpho-physiologically dormant. The embryo does not start to grow until physiological dormancy is broken by cold stratification. Incubating seeds at fluctuating temperatures in the light, after cold stratification, had a stimulating effect on embryo growth and seed germination. Seeds of S. carvifolia and A. sylvestris have non-deep simple morphophysiological dormancy (MPD), since gibberellic acid (GA3) could substitute for cold stratification. This is the first report of non-deep simple MPD that is broken by cold stratification in the Apiaceae. Under natural conditions, physiological dormancy is broken by low temperature conditions during winter. Embryo growth and germination occur in a short time interval when temperatures start rising in early spring. Due to the fact that multiple environmental signals regulate dormancy, seedling emergence in these species is timed very accurately in spring.

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.

Irrigation and crop improvement in temperate and tropical environments

1986 ◽  
Vol 316 (1537) ◽  
pp. 319-330 ◽  
Keyword(s):  
Life Cycle ◽  
Low Temperatures ◽  
Energy Use ◽  
Crop Improvement ◽  
Yield Potential ◽  
Multiple Cropping ◽  
Tropical Environments ◽  
Physiological Processes ◽  
Seasonal Signals ◽  
The Tropics

There is a strong interaction between irrigation and crop improvement, irrigation creating new opportunities and challenges for plant breeders while depending on their progress for its full benefits to be realized. In temperate environments the primary emphasis is on raising yield potential, especially as irrigation enhances the use of agrichemical inputs. Efficiency of water and energy use through the modification of physiological processes and of sensitivity to stress at various stages of the life cycle is also sought. In tropical environments, breeding for greater yield potential and more comprehensive pest and disease resistance are still important. However, shortening the length of the life cycle, reducing its sensitivity to seasonal signals and increasing yield per day may be more important than raising yield per crop because of the scope for multiple cropping made possible by irrigation in the tropics in the absence of contraints by low temperatures.

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