Morphophysiological dormancy and germination ecology in diaspores of the subtropical palm Phoenix canariensis Chabaud

Botany ◽  
2021 ◽  
Author(s):  
Lanlan He ◽  
Ganesh K. Jaganathan ◽  
Baolin Liu
Keyword(s):  
Seed Dormancy ◽  
Seedling Emergence ◽  
Primary Root ◽  
Germination Percentage ◽  
Early Summer ◽  
Germination Ecology ◽  
Phoenix Canariensis ◽  
Morphophysiological Dormancy ◽  
Cotyledonary Petiole ◽  
Seed Dormancy And Germination

The timing of germination is a crucial event in a plant’s life cycle. Seed dormancy and germination mechanisms are important factors regulating seedling emergence. Since detailed experimental evidence for germination pattern of Phoenix canariensis colonizing sub-tropical climate is scarce, we investigated seed dormancy and germination ecology of P. canariensis. We found that the embryo is underdeveloped at the time of dispersal and doubles in size before the cotyledonary petiole (CP) protrudes through the operculum. The primary root and plumule emerge from the elongated CP outside the seed. In light/dark at 30/25°C, the CP emerged from 8% of the diaspores within 30 days and from 76% within 14 weeks. Thus, 8% of the diaspores have MD and the others MPD. Removal of the pericarp and operculum resulted in 100% germination within 5 days in light/dark at 30/25°C. Cold and warm stratification as well as treatment with GA3 significantly increased the germination speed, but the final germination percentage was not significantly increased. Seed germination was synchronized in early summer when seed dormancy was released by cold stratification in the soil over winter. A remote-tubular germination type and intricate root system provide an ecological advantage to the seedling establishment.

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

2013 ◽  
Vol 61 (5) ◽  
pp. 376 ◽  
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.

Germination Ecology of Milkweedvine (Morrenia odorata)

Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 781-785 ◽  
Author(s):  
Megh Singh ◽  
Nagi Reddy Achhireddy
Keyword(s):  
Seed Germination ◽  
Osmotic Stress ◽  
Root Growth ◽  
Seedling Growth ◽  
Shoot Growth ◽  
Seedling Emergence ◽  
Germination Percentage ◽  
Planting Depth ◽  
Germination Ecology ◽  
Optimum Ph

The germination of milkweedvine (Morrenia odorataLindl. ♯3MONOD) seed at 20 or 25 C was unaffected by a 12-h photoperiod. The 12-h photoperiod, however, decreased germination by 50% at 15 C. No germination occurred at 35 C regardless of photoperiod. By alternating 35 C for 12 h with 20 C for 12 h, the germination percentage was 57%. Seedling growth was maximum at alternating temperatures of 30/20 C. Optimum pH for germination and seedling growth was 7 and germination did not occur at pH levels below 6. Seed germination declined steadily at osmotic stress below −0.12 MPa; no germination occurred at −0.5 MPa. Seedling growth was not influenced by osmotic stress down to −0.18 MPa. Germination percentages of seeds kept under aerated water and nonaerated water were similar, but the seedling growth was greater in aerated water. Seedling emergence was maximum from depths of 0.5 to 2.5 cm, but no seedling emerged from 0 or 10 cm. Planting depth was negatively correlated (r = −0.7) with shoot growth but positively correlated (r = +0.98) to root growth.

scholarly journals Factors Affecting Seed Dormancy and Germination of Greater Bur-Parsley (Turgenia latifolia)

2018 ◽  
Vol 36 ◽  
Author(s):  
M. REZVANI ◽  
S.A. SADATIAN ◽  
H. NIKKHAHKOUCHAKSARAEI
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Seed Dormancy ◽  
Seedling Emergence ◽  
Potassium Nitrate ◽  
Germination Percentage ◽  
Dormancy Breaking ◽  
Planting Depth ◽  
Factors Affecting ◽  
Drought And Salt Stresses

ABSTRACT: Our knowledge about seed dormancy breaking and environmental factors affecting seed germination of greater bur-parsley (Turgenia latifolia) is restricted. This study has addressed some seed dormancy breaking techniques, including different concentrations of gibberellic acid (GA3) and potassium nitrate (KNO3), leaching duration, physical scarification as well as some environmental factors effective on seed germination such as salt and drought stresses, pH and seed planting depth. Seed germination was promoted with lower concentrations of KNO3 (0.01 to 0.02 g L-1), while higher concentrations reduced germination percentage. Seed dormancy was declined by low concentrations of GA3 up to 100 ppm. Seeds of greater bur-parsley germinated in a range of pH from 3 to 7. With enhancement of drought and salt stresses, seed germination decreased. Also, there was no seed germination in a high level of stresses. Seedling emergence reduced as planting depth increased. Use of GA3, KNO3, leaching and physical scarification had a positive effect on seed dormancy breaking of greater bur-parsley. The information from the study increases our knowledge about seed dormancy breaking techniques, response of germination to drought and salt stresses and also determination of distribution regions of greater bur-parsley in the future.

GERMINATION, GROWTH AND DEVELOPMENT OF COMMON MILKWEED

1978 ◽  
Vol 58 (2) ◽  
pp. 493-498 ◽  
Author(s):  
PRASANTA C. BHOWMIK
Keyword(s):  
Lateral Roots ◽  
Seedling Emergence ◽  
Primary Root ◽  
Germination Percentage ◽  
Asclepias Syriaca ◽  
Seed Collection ◽  
Primary Roots ◽  
Number Of Leaves ◽  
Primary Root Length ◽  
Storage Temperatures

Germination percentage of common milkweed (Asclepias syriaca L.) seeds was low 1 mo after seed collection. Seed dormancy decreased with time at storage temperatures of −12°, 5° or 21 °C. After 11 months of storage, seeds stored at 21 °C had 15–18% higher germination compared to the seeds stored at −12° and 5 °C. The best seedling emergence was obtained at a temperature of 27 °C when seeds were planted at a depth of 0.5 or 1 cm. Seedling emergence was better in muck or sandy soil than in clay soil. Seedlings developed slowly up to 30 days after emergence at 15 °C under an 8-, 12- or 16-h photoperiod. High temperatures (27 °C) stimulated seedling growth under each photoperiod. Taller seedlings with more leaves, longer primary roots, more lateral roots and adventitious root buds grew at 27 °C as compared to 15° or 21 °C. Increasing the photoperiod from 8 to 16 h increased plant height and number of leaves but not primary root length.

scholarly journals Transcriptome profiles revealed molecular mechanisms of alternating temperatures in breaking the epicotyl morphophysiological dormancy of Polygonatum sibiricum seeds

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dengqun Liao ◽  
Ruipeng An ◽  
Jianhe Wei ◽  
Dongmei Wang ◽  
Xianen Li ◽  
...  
Keyword(s):  
Seed Dormancy ◽  
Seedling Establishment ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Seedling Emergence ◽  
Differentially Expressed ◽  
Natural Environments ◽  
Sequencing Analysis ◽  
Dormancy Release ◽  
Morphophysiological Dormancy

Abstract Background To adapt seasonal climate changes under natural environments, Polygonatum sibiricum seeds have a long period of epicotyl morphophysiological dormancy, which limits their wide-utilization in the large-scale plant progeny propagation. It has been proven that the controlled consecutive warm and cold temperature treatments can effectively break and shorten this seed dormancy status to promote its successful underdeveloped embryo growth, radicle emergence and shoot emergence. To uncover the molecular basis of seed dormancy release and seedling establishment, a SMRT full-length sequencing analysis and an Illumina sequencing-based comparison of P. sibiricum seed transcriptomes were combined to investigate transcriptional changes during warm and cold stratifications. Results A total of 87,251 unigenes, including 46,255 complete sequences, were obtained and 77,148 unigenes (88.42%) were annotated. Gene expression analyses at four stratification stages identified a total of 27,059 DEGs in six pairwise comparisons and revealed that more differentially expressed genes were altered at the Corm stage than at the other stages, especially Str_S and Eme. The expression of 475 hormone metabolism genes and 510 hormone signaling genes was modulated during P. sibiricum seed dormancy release and seedling emergence. One thousand eighteen transcription factors and five hundred nineteen transcription regulators were detected differentially expressed during stratification and germination especially at Corm and Str_S stages. Of 1246 seed dormancy/germination known DEGs, 378, 790, and 199 DEGs were associated with P. sibiricum MD release (Corm vs Seed), epicotyl dormancy release (Str_S vs Corm), and the seedling establishment after the MPD release (Eme vs Str_S). Conclusions A comparison with dormancy- and germination-related genes in Arabidopsis thaliana seeds revealed that genes related to multiple plant hormones, chromatin modifiers and remodelers, DNA methylation, mRNA degradation, endosperm weakening, and cell wall structures coordinately mediate P. sibiricum seed germination, epicotyl dormancy release, and seedling establishment. These results provided the first insights into molecular regulation of P. sibiricum seed epicotyl morphophysiological dormancy release and seedling emergence. They may form the foundation of future studies regarding gene interaction and the specific roles of individual tissues (endosperm, newly-formed corm) in P. sibiricum bulk seed dormancy.

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).

scholarly journals Seed dormancy and germination in Cardiocrinum giganteum var. yunnanense, a perennial herb in China with post-dispersal embryo growth

2020 ◽  
Vol 48 (2) ◽  
pp. 303-314
Author(s):  
Ye-Fang Li ◽  
Jie Song ◽  
Wen-Ling Guan ◽  
Feng-Rong Li
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Practical Knowledge ◽  
Perennial Herb ◽  
Late Winter ◽  
Dormancy Breaking ◽  
Morphophysiological Dormancy ◽  
Summer Temperatures ◽  
Autumn And Winter ◽  
Seed Dormancy And Germination

Seeds of Cardiocrinum giganteum var. yunnanense, which is native to China, has underdeveloped embryos when dispersed from parent plants that did not grow until the second autumn and winter after exposure to summer temperatures. Radicles and cotyledons emerged in late winter and spring. Thus, a 15–16 month period was required from dispersal to seed germination. Under laboratory conditions, this period could be shortened to 5–6 months in a 25°C/15°C (60 days) → 15°C/5°C (60 days) → 5°C (60 days) temperature sequence. Based on dormancy-breaking requirements, the seeds have deep simple morphophysiological dormancy (MPD). This is practical knowledge for propagation of the species from seeds.

Factors controlling seed dormancy and germination response of Brachypodium hybridum growing in the hot arid mountains of the Arabian Desert

Botany ◽  
2019 ◽  
Vol 97 (7) ◽  
pp. 371-379 ◽  
Author(s):  
Masarra Elgabra ◽  
Ali El-Keblawy ◽  
Kareem A. Mosa ◽  
Sameh Soliman
Keyword(s):  
Seed Dormancy ◽  
Light Quality ◽  
Genetic Model ◽  
Germination Rate ◽  
Red Light ◽  
Germination Percentage ◽  
Light Conditions ◽  
One Year ◽  
Native And Introduced Ranges ◽  
Seed Dormancy And Germination

Seed dormancy and germination have been studied in the genetic model Brachypodium species complex in cooler, moist higher latitudes. Studying environmental factors in arid mountains affecting dormancy and germination in Brachypodium complex could determine the factors controlling these processes. This study assesses the impacts of temperature during seed maturation, seed after-ripening, drought, photoperiod, and thermoperiod on final germination and germination rate index of B. hybridum in the Arabian Desert. Seeds were germinated under dark or light conditions and under different ratios of red:far-red light, with three diurnal thermoperiods. The final germination percentage was significantly greater at 15/25 °C and 20/30 °C than at 25/35 °C and in light rather than in darkness. Seeds that reached maturity at 15/25 °C attained greater germination rates and faster germination than those that reached maturity at 20/30 °C. One-year after-ripening enhanced the final germination percentage and reduced photoperiod requirements. Light quality did not affect final germination percentage. The seeds tolerated drought of up to –0.8 MPa polyethylene glycol. The tolerance of B. hybridum seeds produced at higher thermoperiods to moderate levels of osmotic stress and their higher dormancy indicate that this species has the potential to survive the projected global warming in its native and introduced ranges.

Seed Dormancy and Germination Ecology ofCalycanthus floridusL., a Species with Threatened Status in Kentucky

2017 ◽  
Vol 16 (4) ◽  
pp. 488-502
Author(s):  
Christopher A. Adams ◽  
Olamide C. Adejumo ◽  
Moondil Jahan ◽  
Kevin W. Montgomery
Keyword(s):  
Seed Dormancy ◽  
Germination Ecology ◽  
Threatened Status ◽  
Seed Dormancy And Germination
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