scholarly journals A classification system for seed dormancy

2004 ◽  
Vol 14 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Seed Dormancy ◽  
Deep Level ◽  
Basic Mechanism ◽  
Model Species ◽  
Physical Dormancy ◽  
Genetic Studies ◽  
Morphophysiological Dormancy ◽  
Class Level ◽  
Physiological Dormancy

The proposal is made that seed scientists need an internationally acceptable hierarchical system of classification for seed dormancy. Further, we suggest that a modified version of the scheme of the Russian seed physiologist Marianna G. Nikolaeva be adopted. The modified system includes three hierarchical layers – class, level and type; thus, a class may contain levels and types, and a level may contain only types. The system includes five classes of dormancy: physiological dormancy (PD), morphological dormancy (MD), morphophysiological dormancy (MPD), physical dormancy (PY) and combinational dormancy (PY + PD). The most extensive classification schemes are for PD, which contains three levels and five types (in the non-deep level), and MPD, which contains eight levels but no types. PY is not subdivided at all but probably should be, for reasons given. Justifications are presented for not including mechanical dormancy or chemical dormancy in the modified scheme. PD (non-deep level) is the most common kind of dormancy, and occurs in gymnosperms (Coniferales,Gnetales) and in all major clades of angiosperms. Since, first, this is the class and level of dormancy in seeds of wild populations ofArabidopsis thalianaand, secondly, Type 1 (to which seeds ofA. thalianabelong) is also common, and geographically and phylogenetically widespread, it seems that biochemical, molecular and genetic studies on seed dormancy in this model species might have rather broad application in explaining the basic mechanism(s) of physiological dormancy in seeds.

Classification and ecological relationships of seed dormancy in a seasonal moist tropical forest, Panama, Central America

2007 ◽  
Vol 17 (2) ◽  
pp. 127-140 ◽  
Author(s):  
Adriana Sautu ◽  
Jerry M. Baskin ◽  
Carol C. Baskin ◽  
Jose Deago ◽  
Richard Condit
Keyword(s):  
Tropical Forest ◽  
Seed Dormancy ◽  
Tree Species ◽  
Panama Canal ◽  
Physical Dormancy ◽  
Ecological Relationships ◽  
Morphophysiological Dormancy ◽  
Large Size ◽  
Physiological Dormancy ◽  
Dry Seasons

AbstractThis is the first study to determine the class of seed dormancy (or non-dormancy) of a large number of native tree species in a tropical forest, the seasonal moist tropical forest of the Panama Canal Watershed (PCW), or to test the relationships between class of dormancy (or non-dormancy) and various seed and ecological characteristics of the constituent species. Fresh seeds of 49 of 94 tree species were non-dormant (ND), and 45 were dormant (D). Seeds of 23 species had physiological dormancy (PD), 13 physical dormancy (PY), two morphological dormancy (MD), 7 morphophysiological dormancy (MPD) and none combinational dormancy (PY+PD). Seeds with PY were significantly smaller ( < 0.1 g) and drier (moisture content < 16%) at maturity than those that were ND or in the other D classes. Seeds of 62, 42 and 53% of species dispersed in the early rainy, late rainy (LRS) and dry seasons, respectively, were ND. The majority (61%) of species with PD seeds, but only 17% of those with PY seeds, were dispersed in the LRS. The proportion of species with ND seeds was higher in large-size (63%) than in mid-size (35%) and understorey (17%) trees, but differed only slightly between non-pioneers (58%) and pioneers (54%). The proportion of species with D seeds increased only slightly through a precipitation gradient of about 3100 to 1900 mm in the PCW; however, PY increased from 19 to 32% and PD decreased from 63 to 44%.

The great diversity in kinds of seed dormancy: a revision of the Nikolaeva–Baskin classification system for primary seed dormancy

2021 ◽  
pp. 1-29
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Seed Dormancy ◽  
Seed Coat ◽  
Classification System ◽  
Primary Dormancy ◽  
Morphophysiological Dormancy ◽  
Physiological Dormancy ◽  
Whole Seed ◽  
Dust Seeds ◽  
Impermeable Seed Coat ◽  
Morphological Dormancy

Abstract This review provides a revised and expanded word-formula system of whole-seed primary dormancy classification that integrates the scheme of Nikolaeva with that of Baskin and Baskin. Notable changes include the following. (1) The number of named tiers (layers) in the classification hierarchy is increased from three to seven. (2) Formulae are provided for the known kinds of dormancy. (3) Seven subclasses of class morphological dormancy are designated: ‘dust seeds’ of mycoheterotrophs, holoparasites and autotrophs; diaspores of palms; and seeds with cryptogeal germination are new to the system. (4) Level non-deep physiological dormancy (PD) has been divided into two sublevels, each containing three types, and Type 6 is new to the system. (5) Subclass epicotyl PD with two levels, each with three types, has been added to class PD. (6) Level deep (regular) PD is divided into two types. (7) The simple and complex levels of class morphophysiological dormancy (MPD) have been expanded to 12 subclasses, 24 levels and 16 types. (8) Level non-deep simple epicotyl MPD with four types is added to the system. (9) Level deep simple regular epicotyl MPD is divided into four types. (10) Level deep simple double MPD is divided into two types. (11) Seeds with a water-impermeable seed coat in which the embryo-haustorium grows after germination (Canna) has been added to the class combinational dormancy. The hierarchical division of primary seed dormancy into many distinct categories highlights its great diversity and complexity at the whole-seed level, which can be expressed most accurately by dormancy formulae.

Mechanisms of seed dormancy in an annual population of Zostera marina (eelgrass) from The Netherlands

1991 ◽  
Vol 69 (9) ◽  
pp. 1972-1976 ◽  
Author(s):  
Paul Garth Harrison
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Zostera Marina ◽  
Early Winter ◽  
Physical Dormancy ◽  
Physiological Dormancy ◽  
Annual Population ◽  
Effects Of Temperature ◽  
Viable Seeds

Mechanisms of dormancy of seeds from an annual population of the seagrass Zostera marina L. (eelgrass) in the SW Netherlands were investigated in the laboratory. Both physiological dormancy (a requirement for reduced salinity for germination) and physical dormancy (imposed by the seed coat) existed in recently shed seeds. Physiological seed dormancy was partly released in the seed bank by early winter, but physical dormancy lasted longer. By March seeds germinated quickly in the dark in full-strength seawater without artificial weakening of the seed coat. Viable seeds were released with coats that ranged from green (easily ruptured by the embryo) to brown (not easily ruptured); this variation may account for the occasional seedlings that appear during winter. No significant effects of temperature or light on germination were detected. A reexamination of the literature suggests that the observed variation in timing of germination in eelgrass populations may be a result of hitherto overlooked aspects of dormancy. Key words: eelgrass, seagrass, seed coat, seed dormancy, seed germination, Zostera marina.

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.

scholarly journals Promoting Germination in Ornamental Palm Seeds through Dormancy Alleviation

2009 ◽  
Vol 19 (4) ◽  
pp. 682-685 ◽  
Author(s):  
Hector E. Pérez
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Commercial Production ◽  
Physical Dormancy ◽  
Physiological Dormancy ◽  
Morphological Dormancy

Delayed and inconsistent seed germination often hampers commercial production of palms (Arecaceae). Such sporadic germination is commonly due to seed dormancy. Mature, freshly shed seeds of palms typically display a combination of underdeveloped embryos (morphological dormancy) and the inability of developing embryos to rupture covering structures (physiological dormancy). Fruit and seedcoats are capable of imbibing water. Therefore, dormancy due to water-impermeable fruit or seedcoats (physical dormancy) does not occur. Removal of embryo covering structures, such as the pericarp and operculum, followed by incubation under moist, warm (25–35 °C) conditions promotes rapid and complete germination. Complete burial in soil promotes germination of seeds in intact fruit of loulu palm (Pritchardia remota).

Dormancy breakage in Cercis chinensis seeds

2020 ◽  
Vol 100 (6) ◽  
pp. 666-673
Author(s):  
Yunpeng Gao ◽  
Mingwei Zhu ◽  
Qiuyue Ma ◽  
Shuxian Li
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Seed Coat ◽  
Germination Percentage ◽  
Physical Dormancy ◽  
Optimal Method ◽  
Hard Seed ◽  
Positive Effects ◽  
Physiological Dormancy ◽  
Hard Seed Coat

The seeds of Cercis chinensis Bunge are important for reproduction and propagation, but strong dormancy controls their germination. To elucidate the causes of seed dormancy in C. chinensis, we investigated the permeability of the hard seed coat and the contribution of the endosperm to physical dormancy, and we examined the effect of extracts from the seed coat and endosperm. In addition, the effectiveness of scarification methods to break seed dormancy was compared. Cercis chinensis seeds exhibited physical and physiological dormancy. The hard seed coat played an important role in limiting water uptake, and the endosperm acted as a physical barrier that restricted embryo development in imbibed seeds. Germination percentage of Chinese cabbage [Brassica rapa subsp. chinensis (L.) Hanelt] seeds was reduced from 98% (control) to 28.3% and 56.7% with a seed-coat extract and an endosperm extract, respectively. This demonstrated that both the seed coat and endosperm contained endogenous inhibitors, but the seed-coat extract resulted in stronger inhibition. Mechanical scarification, thermal scarification, and chemical scarification had positive effects on C. chinensis seed germination. Soaking non-scarified seeds in gibberellic acid (GA3) solution did not promote germination; however, treatment with exogenous GA3 following scarification significantly improved germination. The optimal method for promoting C. chinensis seed germination was soaking scarified seeds in 500 mg·L−1 GA3 for 24 h followed by cold stratification at 5 °C for 2 mo.

Underdeveloped embryos in dwarf seeds and implications for assignment to dormancy class

2005 ◽  
Vol 15 (4) ◽  
pp. 357-360 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin
Keyword(s):  
Seed Dormancy ◽  
Evolutionary Relationship ◽  
The Other ◽  
Length Ratio ◽  
Morphophysiological Dormancy ◽  
Physiological Dormancy ◽  
Radicle Emergence ◽  
Relationship Of ◽  
Embryo Length ◽  
Morphological Dormancy

Studies were conducted to determine if small embryos (i.e. low embryo length:seed length ratio) in mature dwarf seeds (0.2–2 mm) are underdeveloped. In this case, they would grow (inside the seed) prior to germination, and seeds would have morphological or morphophysiological dormancy. Prior to radicle emergence, embryo length in seeds of Drosera anglica (Droseraceae), Campanula americana, Lobelia appendiculata, L. spicata (Campanulaceae) and Sabatia angularis (Gentianaceae) increased 0, 103, 182, 83 and 57%, respectively. Since embryo growth did not occur in seeds of D. anglica prior to germination, embryos, although small, are fully developed; seeds have only physiological dormancy. The underdeveloped embryo in seeds of C. americana has little or no physiological dormancy; thus, seeds have morphological dormancy. On the other hand, underdeveloped embryos in seeds of L. appendiculata, L. spicata and S. angularis are physiologically dormant, and seeds have morphophysiological dormancy. Therefore, since small embryos in dwarf seeds may or may not be underdeveloped, assignment of seeds to a dormancy class requires that studies be done to determine if embryos grow inside the seed before germination can occur. Such information is important in understanding the evolutionary relationship of the different kinds of seed dormancy.

scholarly journals Ultrafine Bubbles Technology for Breaking Dormancy of Sandalwood Seeds (Santalum album L.

2021 ◽  
Vol 9 (1) ◽  
pp. 27-41
Author(s):  
Juliana Maia ◽  
◽  
Abdul Qadir ◽  
Eny Widajati ◽  
Yohannes Aris Purwanto ◽  
...  
Keyword(s):  
Maximum Growth ◽  
Growth Speed ◽  
Santalum Album ◽  
Physical Dormancy ◽  
Free Oxygen ◽  
Morphophysiological Dormancy ◽  
Breaking Dormancy ◽  
Outermost Surface ◽  
Physiological Dormancy ◽  
Santalum Album L

Sandalwood seed has two types of dormancy, namely physical dormancy and physiological dormancy which is a combination of the Two-part is called morphophysiological dormancy. There is for breaks dormancy in sandalwood for earlier embryo maturation and elongation also it has hard and impermeable skin. Its structure consists of layers of thick-walled palisade-like cells especially on the outermost surface and the inside has a waxy coating and curse material. The objective of this study was to break of seed dormancy with technology Ultrafine Bubbles (UFB) on the morphophysiological dormancy on sandalwood seeds. The experiments used a randomized complete block designed (RCBD) with 3 replications. The data were analyzed using ANOVA and will be continued using the DMRT test at the 5% level. The research was conducted from February - March 0f 2020. The results showed that immersion using UFB water with oxygen 20 ppm or either UFB free oxygen for 24 and 48 hours combined with physical scarification and chemical scarification could accelerate germination in 13 days after germination (appeared radicle), percentage of growth speed (GS) is 4.67%, maximum growth (MG) in 21 days after sowing is 66.67% with normal sprouts 2-4 leaves have grown.

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.

Deep complex morphophysiological dormancy in Sanicula europaea (Apiaceae) fits a recurring pattern of dormancy types in genera with an Arcto-Tertiary distribution

Botany ◽  
2008 ◽  
Vol 86 (12) ◽  
pp. 1370-1377 ◽  
Author(s):  
F. Vandelook ◽  
J. A. Van Assche
Keyword(s):  
Seed Dormancy ◽  
Disjunct Distribution ◽  
Morphophysiological Dormancy ◽  
Physiological Dormancy ◽  
Woodland Herb ◽  
Temperate Deciduous ◽  
Sanicula Europaea ◽  
Pre Treatment ◽  
Temperate Deciduous Forests ◽  
Geographical Distribution Pattern

Genus Sanicula encompasses about 40 species, mainly from temperate deciduous forests and exhibiting an Arcto-Tertiary relict distribution. It has previously been shown that stasis in physiological traits, such as seed dormancy, can occur in genera with an Arcto-Tertiary disjunct distribution. The aim of this study was to determine the requirements for dormancy break and seed germination in the Eurasian woodland herb Sanicula europaea L. Comparing our results with other Apiaceae in a phylogenetic and biogeographic framework enables us to determine whether stasis in seed dormancy has occurred in Sanicula. Experiments under natural conditions showed that the embryo elongates within the seed during winter, when temperatures are low. Seeds of S. europaea germinated immediately after growth of the embryo was completed, and seedlings subsequently emerged when temperatures had risen in spring. A series of tests under temperature-controlled conditions revealed that growth of the embryo and physiological dormancy break occur simultaneously at low temperatures (5 °C), irrespective of a pre-treatment at high temperatures. These results contrast with the dormancy traits of several eastern North American Sanicula species, which presumably require a high temperature pre-treatment before chilling becomes effective. This geographical distribution pattern of seed dormancy traits has also been established independently in several other Arcto-Tertiary relict genera.

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