Morphophysiological seed dormancy inHeptacodium

AbstractHeptacodium miconiodesis an endangered, monotypic genus in the Caprifoliaceae endemic to China. Species within the Caprifoliaceae have been shown to have morphological or morphophysiological dormancy.Heptacodiumseeds had an underdeveloped embryo at the time of fruit dispersal with an embryo that occupied approximately 12% of the seed length. Cold (8 weeks at 5°C) and warm (8 weeks at 20°C) stratification was effective for dormancy release, but embryo growth prior to germination only occurred at warm temperatures (20°C). Gibberellic acid treatment partially substituted for cold stratification. Final seed germination percentage was not different after warm or cold stratification; however, seeds initially exposed to cold stratification germinated faster and more uniformly. Cold stratified seeds reached 50% final germination approximately 55 days sooner than warm stratified seeds. Prior to radicle emergence, embryos grew to fill approximately 60% of the seed through an endosperm channel that occupied the centre portion of the endosperm. Cells in the endosperm channel had thinner cell walls and fewer storage vesicles compared with other endosperm cells. Channel cells formed a dissolution zone ahead of embryo elongation assumed to be involved with enzymatic hydrolysis of storage reserves. Based on these results, it was concluded thatHeptacodiumdisplays the characteristics of seeds with non-deep simple morphophysiological dormancy.

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Dormancy, storability, and germination of seeds in Magnolia punduana (Magnoliaceae)

Botany ◽

10.1139/cjb-2016-0056 ◽

2016 ◽

Vol 94 (10) ◽

pp. 967-973 ◽

Cited By ~ 5

Author(s):

Viheno Iralu ◽

Krishna Upadhaya

Keyword(s):

Tree Species ◽

Germination Percentage ◽

Cold Stratification ◽

Seed Length ◽

Morphophysiological Dormancy ◽

Breaking Dormancy ◽

Physical Treatments ◽

Germinating Seeds ◽

Embryo Length ◽

Threatened Tree Species

Magnolia punduana Hk. f. & Th. (syn. Michelia punduana) is a threatened tree species restricted to northeastern India. The seeds remain dormant for 6 months after dispersal. Seed development and breaking of dormancy was investigated in the present study. Physical treatments such as water (cold, hot, and boiling) and acid and manual scarification proved ineffective in breaking dormancy. Matured seeds had linear and underdeveloped embryos at the time of dispersal with an embryo to seed length (E:S) ratio of 0.13. Germinating seeds showed a significant increase in the embryo length with an E:S ratio of 0.36. Cold stratification (CS) at 5 °C effectively broke dormancy. The embryo grew significantly after CS, indicating the presence of “non-deep simple” morphophysiological dormancy (MPD). Application of GA3 had a significant effect on germination and the lowest germination time with the shortest T50 was observed in seeds treated with 3000 mg·L−1 GA3. KNO3 did not have an influence on breaking dormancy except in combination with GA3, which increased the germination percentage significantly. CS for 90 days and GA3 (3000 mg·L−1) at 25 °C resulted in optimum germination. In the test for viability, seeds stored at 5 °C showed highest viability of 66.66% after 180 days.

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

Seed Science Research ◽

10.1017/s0960258518000132 ◽

2018 ◽

Vol 28 (2) ◽

pp. 131-139 ◽

Cited By ~ 3

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.

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

Seed Science Research ◽

10.1017/s0960258512000268 ◽

2013 ◽

Vol 23 (1) ◽

pp. 75-81 ◽

Cited By ~ 5

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.

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Germination of Viburnum odoratissimum seeds: a new level of morphophysiological dormancy

Seed Science Research ◽

10.1017/s0960258508042177 ◽

2008 ◽

Vol 18 (3) ◽

pp. 179-184 ◽

Cited By ~ 35

Author(s):

Carol C. Baskin ◽

Ching-Te Chien ◽

Shun-Ying Chen ◽

Jerry M. Baskin

Keyword(s):

Incubation Temperature ◽

Cold Stratification ◽

Morphophysiological Dormancy ◽

Physiological Dormancy ◽

Radicle Emergence ◽

Viburnum Odoratissimum

AbstractPrevious studies indicated that seeds of Viburnum odoratissimum had only physiological dormancy (PD), but no measurements of embryos were made during the dormancy-break treatments. Thus, we investigated embryo growth and radicle and cotyledon emergence over a range of temperatures. Seeds have underdeveloped embryos, and their length increased about 300% before radicle emergence. Embryos also had PD, as evidenced by delays in beginning of embryo growth (2–3 weeks) and of germination after embryos were elongated (4 weeks). After radicle emergence, epicotyl emergence was delayed 1–8 weeks, depending on incubation temperature, but cold stratification was not required to break PD of the epicotyl. Unlike seeds of many previously studied Viburnum spp., epicotyls of V. odoratissimum have non-deep, rather than deep, PD. Hence, a new level of MPD called non-deep, simple, epicotyl MPD has been identified.

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

Botany ◽

10.1139/cjb-2016-0149 ◽

2017 ◽

Vol 95 (2) ◽

pp. 147-152 ◽

Cited By ~ 4

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.

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Germination ecology of Trachycarpus fortunei (Arecaceae), a species with morphophysiological and shoot dormancy

Botany ◽

10.1139/cjb-2021-0039 ◽

2021 ◽

Author(s):

Ganesh K. Jaganathan ◽

Narangua Bayarkhuu ◽

LanLan He ◽

Baolin Liu ◽

Jiajin Li ◽

...

Keyword(s):

Cold Stratification ◽

Seed Length ◽

Morphophysiological Dormancy ◽

Wide Range ◽

Cotyledonary Petiole ◽

Summer Temperatures ◽

Strong Inference ◽

Total Seed ◽

Mature Seeds ◽

Natural Dispersal

Beyond strong inference that most of the 2600 known species of Arecaceae produce diaspores with an underdeveloped embryo and therefore have morphological (MD) or morphophysiological dormancy (MPD), little is known about the specific dormancy class or sub-class, and how dormancy-break occurs under ecological conditions. Here, we found that mature seeds of Trachycarpus fortunei collected at the time of natural dispersal had an underdeveloped embryo that was 10% of total seed length. No diaspores germinated over a wide range of temperatures in either light or darkness. Cold-stratification at 4 °C for 1, 2, and 3 months or treatment with 100, 500, and 1000 ppm gibberellic acid (GA3) improved germination percentages, with 3 months cold-stratification or 1000 ppm GA3 resulting in highest germination. The embryo grew inside the seeds during cold-stratification. However, warm stratification did not improve germination. Therefore, seeds of T. fortunei have intermediate complex MPD. Cold stratified seeds moved to spring conditions (15/20 °C) had cotyledonary petiole (CP) elongated, but leaves developed only when the CP elongated seeds were moved to summer temperatures (25/30 °C), suggesting the presence of shoot dormancy. The seedlings are remote-tubular type. This is the first report for Arecaceae indicating the presence of complex MPD.

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Intermediate complex morphophysiological dormancy in the endemic Iberian Aconitum napellus subsp. castellanum (Ranunculaceae)

Seed Science Research ◽

10.1017/s0960258510000048 ◽

2010 ◽

Vol 20 (2) ◽

pp. 109-121 ◽

Cited By ~ 14

Author(s):

José M. Herranz ◽

Miguel Á. Copete ◽

Pablo Ferrandis ◽

Elena Copete

Keyword(s):

Seed Germination ◽

Population Level ◽

Intermediate Complex ◽

Cold Stratification ◽

Morphophysiological Dormancy ◽

Seed Age ◽

Aconitum Napellus ◽

Radicle Emergence ◽

The Mean ◽

Embryo Length

AbstractSeeds of Aconitum napellus subsp. castellanum were physiologically dormant at maturity in early autumn, with underdeveloped embryos. Thus they have morphophysiological dormancy (MPD). Embryos in fresh seeds were on average 1.01 mm long, and they had to grow to 3.60 mm before radicle emergence. Cold stratification at 5°C for 5 months with light enhanced the mean embryo length to 2.73 mm (SE = 0.13) and seed germination to 20%. However, with higher temperatures (15/4, 20/7, 25/10, 28/14 and 32/18°C) embryo growth was small, with no seeds germinating. Optimal germination was achieved after 4 months of cold stratification at 5°C followed by incubation at 20/7°C for 1 month with light, when germination ranged between 70 and 79%, depending on seed age, locality and year of collection. Cold stratification could be substituted by the application of GA3 solution, since mean embryo length in seeds incubated at 25/10°C for 1 month with light was 3.52 mm and the germination was 80%. Since cold stratification was the only requirement for the loss of MPD, the longest embryo growth occurred during this treatment, and GA3 promoted MPD loss, we concluded that A. napellus seeds have intermediate complex MPD. Germination was higher in 4-month stored than in freshly matured seeds. A pronounced variability in germinative patterns at inter-annual and inter-population level was recorded.

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Seed dormancy and germination of the subalpine geophyte Crocus alatavicus (Iridaceae)

Australian Journal of Botany ◽

10.1071/bt13098 ◽

2013 ◽

Vol 61 (5) ◽

pp. 376 ◽

Cited By ~ 6

Author(s):

Ziyan Fu ◽

Dunyan Tan ◽

Jerry M. Baskin ◽

Carol C. Baskin

Keyword(s):

Central Asia ◽

Seed Dormancy ◽

Natural Habitat ◽

Early Summer ◽

Cold Stratification ◽

Dormancy Breaking ◽

Morphophysiological Dormancy ◽

Radicle Emergence ◽

Germination Requirements ◽

Seed Dormancy And Germination

Crocus alatavicus Regel et Sem. is a cormous perennial primarily distributed in central Asia that may have potential in horticulture; however, relatively little is known about seed dormancy in the genus Crocus. The primary aim of the present study was to identify the dormancy breaking and germination requirements of seeds of C. alatvicus and to assign them to a dormancy category. In its natural habitat, the underdeveloped embryo in C. alatavicus seeds grows in early summer, and radicles emerge in early autumn. However, cotyledon emergence is delayed until the following spring. Radicle emergence was promoted by warm stratification and cotyledon emergence by cold stratification. GA3 was ineffective in promoting either radicle or epicotyl emergence. We conclude that seeds of C. alatavicus have deep simple epicotyl morphophysiological dormancy of the type C1bB(root) – C3(shoot). To our knowledge, this is the first detailed study on the ecophysiology of seed dormancy and germination in the genus Crocus.

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Deep simple morphophysiological dormancy in seeds of the basal taxad Cephalotaxus

Seed Science Research ◽

10.1017/s0960258511000134 ◽

2011 ◽

Vol 21 (3) ◽

pp. 215-226 ◽

Cited By ~ 7

Author(s):

Chia Ju Yang ◽

Ching-Te Chien ◽

Yue Ken Liao ◽

Shun-Ying Chen ◽

Jerry M. Baskin ◽

...

Keyword(s):

Sensu Stricto ◽

Cold Stratification ◽

Warm Temperature ◽

Cold Temperatures ◽

Morphophysiological Dormancy ◽

Medicinal Value ◽

Radicle Emergence ◽

Mature Seeds ◽

Shoot Emergence ◽

Seeds Germination

AbstractAlthough mature seeds of the monogeneric conifer family Cephalotaxaceae sensu stricto have underdeveloped embryos, no definitive studies have been done to classify dormancy in this family. Our primary purpose was to determine the kind of dormancy in seeds of Cephalotaxus wilsoniana and to put the results into a broad phylogenetic context for gymnosperms. The species is of horticultural and medicinal value, and information is needed on how to propagate it efficiently from seeds. Embryo growth and germination were monitored for seeds at warm, cold and warm plus cold temperatures, and germination was monitored for seeds subjected to: (1) cold → warm → cold → warm; and (2) warm → cold → warm → cold → warm temperature sequences. The effects of gibberellic acids GA3 and GA4 were tested on radicle emergence in ungerminated seeds and on shoot emergence in root-emerged seeds. Germination was promoted by ≥ 36 weeks of warm stratification followed by ≥ 8 weeks of cold stratification, but only if seeds were returned to high temperatures. The underdeveloped embryo must increase in length by >120% before the radicle emerges. Neither GA3 nor GA4 was effective in promoting radicle emergence; however, both plant growth regulators increased rate (but not percentage) of shoot emergence in root-emerged seeds. We conclude that seeds of C. wilsoniana have the deep simple level of morphophysiological dormancy (MPD), C1b-C3-B1b; thus, warm stratification followed by cold stratification and then warm-temperature incubation are required for germination. In gymnosperms, MPD is known in cycads, Ginkgo and now in three families of conifers.

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Epicotyl morphophysiological dormancy and storage behaviour of seeds of Strychnos nux-vomica, Strychnos potatorum and Strychnos benthamii (Loganiaceae)

Seed Science Research ◽

10.1017/s0960258520000203 ◽

2020 ◽

pp. 1-9

Author(s):

Deshika L. Muthuthanthirige ◽

W.M.G. Asanga S.T.B. Wijetunga ◽

K.M.G. Gehan Jayasuriya

Keyword(s):

Seed Storage ◽

Test Time ◽

Seed Length ◽

Morphophysiological Dormancy ◽

Radicle Emergence ◽

Seasonal Habitats ◽

Strychnos Potatorum ◽

And Storage ◽

Shoot Emergence ◽

Seeds Germination

Abstract We hypothesized that Strychnos nux-vomica and Strychnos potatorum in seasonal tropical ecosystems have dormant desiccation-tolerant seeds, while those of Strychnos benthamii growing in aseasonal wet habitats have non-dormant desiccation-sensitive seeds. Germination, imbibition, the effect of gibberellic acid on germination and changes in the embryo to seed length ratio (E:S) during incubation were determined for the three species. Seed storage behaviour was identified with the hundred seed test. Time taken for epicotyl emergence was recorded. Radicle emergence of S. nux-vomica, S. potatorum and S. benthamii at 25°C under light/dark conditions (12/12 h) was completed within 76, 49 and 11 d, respectively. S. nux-vomica and S. potatorum seeds incubated on GA3 germinated to a higher percentage than non-treated seeds. E:S of S. nux-vomica, S. potatorum and S. benthamii had increased by 38.2, 34.5 and 25.5%, respectively, at radicle emergence. Shoot emergence of S. nux-vomica, S. potatorum and S. benthamii was observed after 76, 74 and 45 d from radicle emergence, respectively. Thus, it can be concluded that the seeds of all three species have epicotyl morphophysiological dormancy. Hundred seed tests revealed that S. nux-vomica and S. potatorum seeds were desiccation-tolerant, while those of S. benthamii were desiccation-sensitive. Our study showed that species from seasonal habitats (S. nux-vomica and S. potatorum) have desiccation-tolerant morphophysiologically dormant seeds, while those from an aseasonal habitat (S. benthamii) have desiccation-sensitive morphophysiologically dormant seeds, revealing that their dormancy and desiccation tolerance behaviour are adaptations to their environment.

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