Seed dormancy in the early diverging eudicot Trochodendron aralioides (Trochodendraceae)

2006 ◽  
Vol 16 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin ◽  
Ching-Te Chien ◽  
Shun-Ying Chen
Keyword(s):  
Seed Dormancy ◽  
Seed Plants ◽  
Seed Length ◽  
Seed Maturity ◽  
Early Tertiary ◽  
Radicle Emergence ◽  
Primitive Condition ◽  
Embryo Length ◽  
Morphological Dormancy

The embryo length/seed length (E/S) ratio of the early diverging eudicot Trochodendron aralioides is 0.34. Embryos in fresh seeds were 0.36±0.01 mm long, and they increased in length by about 250% (in 20 d) before radicle emergence (germination) occurred, demonstrating that the embryo is underdeveloped at seed maturity. Seeds germinated to 95–100% at 20/10, 25/15 and 30/15°C in light in ≤4 weeks, without any pretreatment, but no seeds germinated in darkness. Thus, seeds of T. aralioides have morphological dormancy (MD), which is considered to be the primitive condition in seed plants, and MD probably has existed in the genus Trochodendron since its origin in the early Tertiary.

Underdeveloped embryos and kinds of dormancy in seeds of two gymnosperms: Podocarpus costalis and Nageia nagi (Podocarpaceae)

2013 ◽  
Vol 23 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Shun-Ying Chen ◽  
Carol C. Baskin ◽  
Jerry M. Baskin ◽  
Ching-Te Chien
Keyword(s):  
Seed Plants ◽  
Cold Stratification ◽  
Morphophysiological Dormancy ◽  
Seed Maturity ◽  
Basal Clade ◽  
Radicle Emergence ◽  
Primitive Condition ◽  
Morphological Dormancy

AbstractAlthough it has been speculated that seeds of the gymnosperm family Podocarpaceae have an underdeveloped embryo, no detailed studies have been done to definitively answer this question. Our purpose was to determine if embryos in seeds of two species of Podocarpaceae, Podocarpus costalis and Nageia nagi, from Taiwan are underdeveloped and to examine the kind of dormancy the seeds have. Embryos in fresh seeds of P. costalis were 4.6 ± 0.5 mm long, and they increased in length by about 54% before radicle emergence (germination), demonstrating that the embryo is underdeveloped at seed maturity. Seeds germinated to >90% at 30/20, 25/15 and 25°C in light in ≤ 4 weeks, without any cold stratification pretreatment. Thus, seeds of P. costalis have morphological dormancy (MD). Embryos in fresh seeds of N. nagi were 7.4 ± 0.8 mm long and they increased in length by about 39% before radicle emergence (germination) occurred, indicating that the embryo is underdeveloped at seed maturity. Seeds germinated to < 25% at 30/20 and 25°C in light in 4 weeks but to >90% at the same temperatures in 12 weeks. Thus, most seeds of N. nagi have morphophysiological dormancy (MPD). Although underdeveloped embryos are considered to be a primitive condition in seed plants, they also occur in the most advanced orders. The occurrence of underdeveloped embryos in Podocarpaceae documents that they are not restricted to a basal clade in gymnosperms.

scholarly journals Different levels of morphophysiological seed dormancy in Ribes alpinum and R. uva-crispa (Grossulariaceae) facilitate adaptation to differentiated habitats

2020 ◽  
Vol 29 (2) ◽  
pp. e017
Author(s):  
Raquel Herranz-Ferrer ◽  
Miguel Ángel Copete-Carreño ◽  
José María Herranz-Sanz ◽  
Elena Copete-Carreño ◽  
Pablo Ferrandis-Gotor
Keyword(s):  
Seed Dormancy ◽  
Seedling Emergence ◽  
Late Summer ◽  
Late Winter ◽  
Minimal Size ◽  
Morphophysiological Dormancy ◽  
Radicle Emergence ◽  
Embryo Length ◽  
Different Levels ◽  
Morphological Dormancy

Aim of the study: To study the germination ecology of two species of the genus Ribes to reveal their levels of morphophysiological dormancy (MPD) and to facilitate the production of plants from seeds, a key tool for population reinforcement.Area of study: Experiments were carried out both outdoors and in the laboratory in Albacete (Spain) with seeds from the Meridional Iberian System mountain range.Material and methods: Seeds from one population of Ribes alpinum and from other of Ribes uva-crispa were collected during several years. Embryo length, radicle and seedling emergence, and effects on germination of stratification and GA3 were analysed to determine the level of MPD.Main results: In R. alpinum, embryo length in fresh seeds was 0.49 mm, needing to grow to 1.30 mm to germinate. Warm stratification (25/10ºC) promoted embryo length enlargement to 0.97 mm. Afterwards, seeds germinated within a wide temperature range. Embryo growth and seedling emergence occur late summer-early autumn. In R. uva-crispa, embryo length in fresh seeds was 0.52 mm, being 2.10 mm the minimal size to germinate. Embryos exposed to a moderately warm stratification (20/7ºC + 15/4ºC) followed by cold (5ºC) grew to 2.30 mm. Then, seeds germinated ≥ 80% when incubated at temperatures ≥ 15/4ºC. Embryos grew in autumn/early winter, and seedlings emerged late winter-early spring.Research highlights: These results showed that R. alpinum seeds have a nondeep simple MPD while R. uva-crispa seeds have a nondeep complex MPD. Moreover, the different germinative models found for each species help explain their installation in distinct habitats.Keywords: Ribes; seed dormancy break; radicle emergence; seedling emergence; nondeep simple and nondeep complex MPD.Abbreviations used: Morphophysiological dormancy (MPD), morphological dormancy (MD), Gibberellic acid (GA3), months (m).

Nymphaeaceae: a basal angiosperm family (ANITA grade) with a fully developed embryo

2007 ◽  
Vol 17 (4) ◽  
pp. 293-296 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin
Keyword(s):  
The Other ◽  
Basal Angiosperm ◽  
Seed Length ◽  
Basal Angiosperms ◽  
Phylogenetic Studies ◽  
Seed Maturity ◽  
Other Hand ◽  
Molecular Phylogenetic ◽  
Radicle Emergence ◽  
Embryo Length

AbstractRudimentary, broad and small linear embryos occur among members of the most primitive (basal) extant angiosperms, collectively called the ANITA grade (i.e.Amborella,NymphaealesandAustrobaileyales).Amborella(rudimentary) andAustrobaileyales(rudimentary inAustrobaileyaceae,IlliciaceaeandSchisandraceaeand small linear inTrimeniaceae) have kinds of embryos that are known to be underdeveloped; consequently, they must grow inside the seed prior to radicle emergence (germination). On the other hand, it is not known if broad embryos need to grow before radicles can emerge, and whether they are underdeveloped or fully developed. Thus, we addressed the question: ‘Is the broad embryo ofNymphaealesalso underdeveloped?’. Although the embryo length : seed length ratios inNymphaeaAlbert Greenburg,N.capensisvar.zanzibariensisandN.immutabiliswere 0.311, 0.349 and 0.234, respectively, embryos did not grow prior to radicle emergence. Thus, they are fully developed at seed maturity. IfAmborellaandNymphaealesare equally the most basal angiosperms, as some molecular phylogenetic studies indicate, then we must conclude that the broad and rudimentary embryos are equally primitive.

Seed dormancy in Campanulaceae: morphological and morphophysiological dormancy in six species of Hawaiian lobelioids

Botany ◽  
2020 ◽  
Vol 98 (6) ◽  
pp. 327-332
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin ◽  
Alvin Yoshinaga ◽  
Dustin Wolkis
Keyword(s):  
Seed Dormancy ◽  
The Other ◽  
Morphophysiological Dormancy ◽  
Body Of Knowledge ◽  
Temperature Regimes ◽  
Growing Body ◽  
Radicle Emergence ◽  
The Mean ◽  
Embryo Length ◽  
Morphological Dormancy

We determined the requirements for dormancy break/germination and kind of dormancy in seeds of the Hawaiian lobelioids Cyanea kunthiana, Delissea rhytidoperma, Lobelia grayana, L. hypoleuca, Trematolobelia grandifolia, and T. singularis. Fresh seeds were incubated in light/dark at 15/6, 20/10, and 25/15 °C, and germination monitored at two-week intervals for 14 weeks. For each species, the mean embryo length (E): seed (S) length ratio was determined for freshly matured seeds and for seeds at the time the seed coat split but before radicle emergence (germination). The embryo in seeds of all six species incubated at 25/15 °C grew inside the seed prior to germination (42%–148% increase in E:S ratio, depending on species). Seeds of L. grayana and L. hypoleuca have morphological dormancy (MD); they germinated to 82%–98% at the three temperature regimes in 4 weeks. Seeds of the other species have nondeep simple morphophysiological dormancy (MPD) and require >4 weeks for maximum germination to occur. Our results add to the growing body of knowledge about the kind (class) of seed dormancy in Campanulaceae, which suggests that seeds of members of this family have either MD or MPD and embryos grow at warm (≥15 °C) temperatures.

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.

Three levels of simple morphophysiological dormancy in seeds of Ilex (Aquifoliaceae) species from Argentina

2018 ◽  
Vol 28 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Guadalupe Galíndez ◽  
Diana Ceccato ◽  
Rosana Bubillo ◽  
Lucía Lindow-López ◽  
Gisela Malagrina ◽  
...  
Keyword(s):  
Seed Dormancy ◽  
Incubation Temperature ◽  
Fold Increase ◽  
Germination Percentage ◽  
Cold Stratification ◽  
Subtropical Region ◽  
Seed Length ◽  
Morphophysiological Dormancy ◽  
Effects Of Temperature ◽  
Embryo Length

AbstractAs a contribution to understanding the world biogeography of seed dormancy in the cosmopolitan genus Ilex, we studied seeds of I. argentina, I. brasiliensis, I. brevicuspis, I. dumosa, I. paraguariensis and I. theezans from the subtropical region of Argentina. We hypothesized that seeds of these species have non-deep simple morphophysiological dormancy (MPD). Effects of temperature, cold stratification and gibberellic acid (GA3) on seed germination and embryo growth were tested. Regardless of incubation temperature, little or no germination occurred for any species until ≥6 weeks. There was an up to 3-fold increase in embryo length to seed length (E:S) ratio before seeds germinated, and embryos grew only during warm-stratifying conditions. Seeds of I. brasiliensis, I. brevicuspis and I. theezans had non-deep simple MPD and germinated to ≥80% after 12, 24 and 16 weeks, respectively. Cold stratification increased germination of I. brasiliensis and I. brevicuspis, and GA3 increased the rate but not final germination percentage of I. brasiliensis and I. theezans. Fresh seeds of I. dumosa required 40 weeks of warm stratification to germinate to 53%, while those after-ripened for 2 months germinated to 81% after 30 weeks; this species has intermediate simple MPD. Seeds of I. argentina and I. paraguariensis germinated to 15 and 21%, respectively, after 40 weeks of warm stratification and did not after-ripen or respond to GA3; these seeds have deep simple MPD. This is the first report of intermediate and deep simple MPD that is broken by warm stratification, thereby increasing our knowledge of seed dormancy in Ilex and in subtropical regions.

Экологическая и сортовая изменчивость морфометрических параметров семян моркови

2019 ◽  
Author(s):  
A.F. Bukharov ◽  
D.N. Baleev ◽  
E.V. Kashnova ◽  
G.V. Kasaeva ◽  
M.I. Ivanova ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Morphometric Parameters ◽  
Sodium Hypochlorite Solution ◽  
The West ◽  
Seed Length ◽  
Hypochlorite Solution ◽  
Aqueous Sodium ◽  
Altai Region ◽  
Experimental Station ◽  
Embryo Length

Цель исследований: изучение влияния сортового и экологического факторов на изменчивость морфометрических (длина семени, эндосперма и зародыша) параметров семян моркови в системе двухфакторного опыта. Объекты для изучения – оригинальные семена сортов Шантенэ 2461 и Боярыня. Опыты были заложены в 2015–2017 годах на Западно-Сибирской овощной опытной станции ФГБНУ ВНИИО в южной части Первомайского района Алтайского края. Преобладающие почвы – черноземы выщелоченные и обыкновенные. Повторность опыта трехкратная, в каждой повторности не менее 20 семян. Измерение длины семени и эндосперма проводили штангенциркулем (ГОСТ 166-89), длину зародыша определяли с использованием микроскопа Микромед и видеоокуляра DCM 300 MD. Семена замачивали в 14%-ном водном растворе гипохлорита натрия в течение 1 ч, после чего измеряли длину семени, эндосперма и зародыша и рассчитывали соотношение длины зародыша (E) к длине эндосперма (S). Семена двух сортов моркови, за годы исследования существенно различались по длине семян (Р < 0,001). Длина эндосперма сорта Боярыня в среднем за годы исследований была меньше (Р < 0,001) по сравнению с Шантенэ 2461. Длина зародыша также существенно отличалась (Р < 0,001) в зависимости от сорта. Экологический фактор значительно влиял на длину семени (Р=0,005) и эндосперма (Р=0,003). На длину зародыша основное влияние оказывал фактор сорта (Р < 0,001). На отношение длины зародыша к длине эндосперма также в значительной степени влиял фактор сорта (Р = 0,006). Исследования показали, что изменчивость морфометрических параметров семян обусловлена как влиянием сорта, так и влиянием условий года репродукции. Длина зародыша по сравнению с другими элементами семени варьирует сильнее и в большей степени зависит от влияния наследственного фактора. Это позволяет сделать вывод о возможности селекционного изменения линейных, а также относительных размеров морфологических элементов семени.The article is devoted to the study of the effect of varietal and environmental factors on the variability of morphometric (seed length, endosperm and germ) parameters of carrot seeds. The objects for the study were the original seeds of different varieties grown in 2015, 2016 and 2017. Seeds obtained from two varieties of carrots over the years of research differed significantly in the length of the seeds (P <0.001). The length of the endosperm varieties Boyarynya on average over the years of research was less (P <0.001) compared with Shantane 2461. The experiments were conducted in 2015-2017 at the West Siberian Vegetable Experimental Station in the southern part of the Pervomaisky district of the Altai region. The prevailing soils are leached and ordinary chernozems. Experiment replication is 3, each repeatability consists at least 20 seeds. The measurement of the length of the seed and the endosperm was carried out with Vernier caliper (GOST 166-89), the length of the embryo was determined using microscope Mikromed and video-ocular DCM 300 MD. Seeds were soaked in 14% aqueous sodium hypochlorite solution for 1 h, and then measured the length of the seed, the endosperm and the embryo, and calculated the ratio of the length of the embryo (E) to the length of the endosperm (S). Embryo length was also significantly different (P <0.001) depending on the variety. The environmental factor had a significant impact on the length of the seed (P = 0.005) and endosperm (P = 0.003). The length of the embryo was mainly affected by the factor of the variety (P <0.001). The ratio of the embryo length to the endosperm length was largely influenced by the factor of the variety (P = 0.006). Our studies have shown that the variability of the morphometric parameters of seeds is due to both the influence of the variety and the conditions of the year of reproduction. In comparison with other elements of the seed, the embryo length varies more and depends more on the influence of the hereditary factor. This allows us to conclude about the possibility of a selection change in linear as well as relative sizes of the morphological elements of the seed.

scholarly journals THE EVOLUTION OF EMBRYO SIZE IN ANGIOSPERMS AND OTHER SEED PLANTS: IMPLICATIONS FOR THE EVOLUTION OF SEED DORMANCY

Evolution ◽  
2002 ◽  
Vol 56 (11) ◽  
pp. 2112-2125 ◽  
Author(s):  
Tara A. Forbis ◽  
Sandra K. Floyd ◽  
Alan de Queiroz
Keyword(s):  
Seed Dormancy ◽  
Seed Plants ◽  
Embryo Size

Regulation of seed dormancy by abscisic acid and DELAY OF GERMINATION 1

2015 ◽  
Vol 25 (2) ◽  
pp. 82-98 ◽  
Author(s):  
Bas J.W. Dekkers ◽  
Leónie Bentsink
Keyword(s):  
Abscisic Acid ◽  
Seed Dormancy ◽  
Plant Hormone ◽  
Complex Trait ◽  
Hormone Interactions ◽  
Physiological Dormancy ◽  
Recent Developments ◽  
Radicle Emergence ◽  
Dormancy Induction

AbstractPhysiological dormancy has been described as a physiological inhibiting mechanism that prevents radicle emergence. It can be caused by the embryo (embryo dormancy) as well as by the structures that cover the embryo. One of its functions is to time plant growth and reproduction to the most optimal season and therefore, in nature, dormancy is an important adaptive trait that is under selective pressure. Dormancy is a complex trait that is affected by many loci, as well as by an intricate web of plant hormone interactions. Moreover, it is strongly affected by a multitude of environmental factors. Its induction, maintenance, cycling and loss come down to the central paradigm, which is the balance between two key hormonal regulators, i.e. the plant hormone abscisic acid (ABA), which is required for dormancy induction, and gibberellins (GA), which are required for germination. In this review we will summarize recent developments in dormancy research (mainly) in the model plant Arabidopsis thaliana, focusing on two key players for dormancy induction, i.e. the plant hormone ABA and the DELAY OF GERMINATION 1 (DOG1) gene. We will address the role of ABA and DOG1 in relation to various aspects of seed dormancy, i.e. induction during seed maturation, loss during dry seed afterripening, the rehydrated state (including dormancy cycling) and the switch to germination.

scholarly journals Seed Dormancy in Hairy Vetch (Vicia villosa Roth) Is Influenced by Genotype and Environment

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1804
Author(s):  
L. Kissing Kucek ◽  
M.D. Azevedo ◽  
S.S. Eagen ◽  
N.J. Ehlke ◽  
R.J. Hayes ◽  
...  
Keyword(s):  
Seed Dormancy ◽  
Environmental Effects ◽  
Maximum Temperature ◽  
Dormant Seed ◽  
Weather Variables ◽  
Physical Dormancy ◽  
Vicia Villosa ◽  
Maternal Line ◽  
Seed Maturity ◽  
Agricultural Use

Seed dormancy complicates the agricultural use of many legume species. Understanding the genetic and environmental drivers of seed dormancy is necessary for advancing crop improvement for legumes, such as Vicia villosa. In this study, we quantify the magnitude of genetic and environmental effects on physical dormancy among 1488 maternal V. villosa plants from 18 diverse environments. Furthermore, we explore the relationship between physical dormancy and environmental conditions during seed development. Additive genetic variance (h2) accounted for 40% of the variance, while the growing environment explained 28% of the variance in physical dormancy. Maternal lines showed complete variance in physical dormancy, as one line was 100% dormant, and 56 lines were 0% dormant. Distributions of physical dormancy varied widely among seed production environments, with some site-years strongly skewed toward physically dormant seed, while other site-years exhibited little dormant seed. Twenty-three weather variables were associated with environmental and error effects of physical dormancy. High mean and minimum relative humidity, low mean and maximum temperature, and high precipitation weakly grouped with low physical dormancy. Weather variables calculated from fixed time windows approximating seed maturity to seed harvest at each site-year tended to be less predictive than biological seed drying windows calculated based on seed maturity of each maternal line. Overall, individual and cumulative effects of weather variables were poor predictors of physical dormancy. Moderate heritability indicates that breeding programs can select against physical dormancy and improve V. villosa for agricultural use. Marker-based approaches would maximize selection for physical dormancy by reducing the influence of unpredictable environmental effects.

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