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Jerry M Baskin - One of the best experts on this subject based on the ideXlab platform.
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morphophysiological dormancy in seeds of convallaria keiskei and a proposal to recognize two types of double dormancy in seed dormancy classification
Seed Science Research, 2015Co-Authors: Tetsuya Kondo, Shyam S Phartyal, Mizuki Narita, Siti N Hidayati, Jeffrey L Walck, Jerry M Baskin, Carol C BaskinAbstract:Convallaria majalis has double dormancy and hypogeal germination, but no information is available on Embryo Growth or on the effects of light and gibberellic acid (GA 3 ) on germination in this genus. Therefore, we investigated Embryo Growth and other germination features in seeds of C. keiskei and compared the data with those of Trillium camschatcense in another study. Until now, in seeds with double dormancy, Embryo Growth and germination (epigeal) have been studied in detail only for seeds of T. camschatcense . Phenology of Embryo Growth and emergence of cotyledonary petiole/root (hereafter root) and shoot in seeds of C. keiskei were monitored outdoors. Effects of temperature, light and GA 3 on Embryo Growth and root and shoot emergence were tested under laboratory conditions. Roots emerged the first spring following seed dispersal in autumn. The Embryo grew soon after root emergence, and germination was hypogeal. Seeds with an emerged root formed buds from which a shoot (leaf) emerged above ground during the second spring. Alternating temperatures and light had negative effects on root emergence, and GA 3 did not substitute for cold stratification in root emergence. Seeds of C. keiskei have double dormancy, but it differs from that in T. camschatcense . Based on differences in Embryo Growth before ( T. camschatcense ) versus after ( C. keiskei ) root emergence, and on epigeal ( T. camschatcense ) versus hypogeal ( C. keiskei ) germination, we suggest that two types of deep simple double morphophysiological dormancy (MPD) be recognized. Since Embryo Growth in C. keiskei does not fit the standard definition of MPD, we propose to expand this definition.
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intermediate complex morphophysiological dormancy in seeds of the cold desert sand dune geophyte eremurus anisopterus xanthorrhoeaceae liliaceae s l
Annals of Botany, 2014Co-Authors: Jannathan Mamut, Carol C Baskin, Dun Yan Tan, Jerry M BaskinAbstract:BACKGROUND AND AIMS Little is known about morphological (MD) or morphophysiological (MPD) dormancy in cold desert species and in particular those in Liliaceae sensu lato, an important floristic element in the cold deserts of Central Asia with underdeveloped embyos. The primary aim of this study was to determine if seeds of the cold desert liliaceous perennial ephemeral Eremurus anisopterus has MD or MPD, and, if it is MPD, then at what level. METHODS Embryo Growth and germination was monitored in seeds subjected to natural and simulated natural temperature regimes and the effects of after-ripening and GA3 on dormancy break were tested. In addition, the temperature requirements for Embryo Growth and dormancy break were investigated. KEY RESULTS At the time of seed dispersal in summer, the Embryo length:seed length (E:S) ratio was 0·73, but it increased to 0·87 before germination. Fresh seeds did not germinate during 1 month of incubation in either light or darkness over a range of temperatures. Thus, seeds have MPD, and, after >12 weeks incubation at 5/2 °C, both Embryo Growth and germination occurred, showing that they have a complex level of MPD. Since both after-ripening and GA3 increase the germination percentage, seeds have intermediate complex MPD. CONCLUSIONS Embryos in after-ripened seeds of E. anisopterus can grow at low temperatures in late autumn, but if the soil is dry in autumn then Growth is delayed until snowmelt wets the soil in early spring. The ecological advantage of Embryo Growth phenology is that seeds can germinate at a time (spring) when sand moisture conditions in the desert are suitable for seedling establishment.
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physiology morphology and phenology of seed dormancy break and germination in the endemic iberian species narcissus hispanicus amaryllidaceae
Annals of Botany, 2011Co-Authors: Elena Copete, Pablo Ferrandis, Jose M Herranz, Carol C Baskin, Jerry M BaskinAbstract:†Background and Aims Only very few studies have been carried out on seed dormancy/germination in the large monocot genus Narcissus. A primary aim of this study was to determine the kind of seed dormancy in Narcissus hispanicus and relate the dormancy breaking and germination requirements to the field situation. †Methods Embryo Growth, radicle emergence and shoot Growth were studied by subjecting seeds with and without an emerged radicle to different periods of warm, cold or warm plus cold in natural temperatures outdoors and under controlled laboratory conditions. †Key Results Mean Embryo length in fresh seeds was approx. 1.31 mm, and Embryos had to grow to 2.21 mm before radicle emergence. Embryos grew to full size and seeds germinated (radicles emerged) when they were warm stratified for 90 d and then incubated at cool temperatures for 30 d. However, the Embryos grew only a little and no seeds germinated when they were incubated at 9/5, 10 or 15/4 8C for 30 d following a moist cold pre-treatment at 5, 9/5 or 108C. In the natural habitat of N. hispanicus, seeds are dispersed in late May, the Embryo elongates in autumn and radicles emerge (seeds germinate) in early November; however, if the seeds are exposed to low temperatures before Embryo Growth is completed, they re-enter dormancy (secondary dormancy). The shoot does not emerge until March, after germinated seeds are cold stratified in winter. †Conclusion Seeds of N. hispanicus have deep simple epicotyl morphophysiological dormancy (MPD), with the dormancy formula C1bB(root) ‐ C3(epicotyl). This is the first study on seeds with simple MPD to show that Embryos in advanced stages of Growth can re-enter dormancy (secondary dormancy).
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morphological dormancy in seeds of the autumn germinating shrub lonicera caerulea var emphyllocalyx caprifoliaceae
Plant Species Biology, 2009Co-Authors: Shyam S Phartyal, Tetsuya Kondo, Yoichiro Hoshino, Jerry M Baskin, Carol C BaskinAbstract:To better understand the germination ecophysiology of the genus Lonicera, the dormancy class, temperature requirements for Embryo Growth and radicle emergence and phenology of seedling emergence were determined for Lonicera caerulea var. emphyllocalyx .A t maturity, seeds have an underdeveloped Embryo (approximately 28% of the length of full-grown Embryos). Embryos in fresh seeds grew to full length at 15, 20, 20/10 and 25/15°C within 3 weeks, but failed to grow at 10°C and at 30°C. Radicles emerged from 86–100% of freshly matured seeds in light at 15, 20, 20/10 and 25/15°C within 28 days, but failed to emerge at 10°C. Radicles emerged equally well in a 12 h photoperiod and in continuous darkness at 25/15°C. Rapid Embryo Growth and germination over a range of conditions indicate that seeds of this taxon have morphological dormancy (MD); this is the first report of MD in a species of Lonicera. Seeds are dispersed in summer, at which time high temperatures promote Embryo Growth. Embryos grow to the critical length for germination in approximately 1 month; the peak of seedling emergence occurs in early autumn. Radicles emerged within 2 months from 98% of seeds buried at soil depths of 2 cm and 10 cm in the field in August in Sapporo, Japan; thus, seeds have no potential to form a persistent soil seed bank. However, seeds sown too late in autumn for Embryos to grow remained viable and germinated the following summer when temperatures were high enough to promote Embryo Growth.
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germination of viburnum odoratissimum seeds a new level of morphophysiological dormancy
Seed Science Research, 2008Co-Authors: Chingte Chien, Shunying Chen, Jerry M Baskin, Carol C BaskinAbstract:Previous 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.
Carol C Baskin - One of the best experts on this subject based on the ideXlab platform.
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The morphophysiological dormancy in Amborella trichopoda seeds is a pleisiomorphic trait in angiosperms
Annals of Botany, 2017Co-Authors: Bruno Fogliani, Gildas Gâteble, M. Villegente, Carol C Baskin, Isabelle Fabre, Nicolas Klein, Nicolas Anger, Charles P. ScuttAbstract:Background and Aims Recent parsimony-based reconstructions suggest that seeds of early angiosperms had either morphophysiological or physiological dormancy, with the former considered as more probable. The aim of this study was to determine the class of seed dormancy present in Amborella trichopoda, the sole living representative of the most basal angiosperm lineage Amborellales, with a view to resolving fully the class of dormancy present at the base of the angiosperm clade. Methods Drupes of A. trichopoda without fleshy parts were germinated and dissected to observe their structure and Embryo Growth. Pre-treatments including acid scarification, gibberellin treatment and seed excision were tested to determine their influence on dormancy breakage and germination. Character-state mapping by maximum parsimony, incorporating data from the present work and published sources, was then used to determine the likely class of dormancy present in early angiosperms. Key Results Germination in A. trichopoda requires a warm stratification period of at least approx. 90 d, which is followed by endosperm swelling, causing the water-permeable pericarp-mesocarp envelope to split open. The Embryo then grows rapidly within the seed, to radicle emergence some 17 d later and cotyledon emergence after an additional 24 d. Gibberellin treatment, acid scarification and excision of seeds from the surrounding drupe tissues all promoted germination by shortening the initial phase of dormancy, prior to Embryo Growth. Conclusions Seeds of A. trichopoda have non-deep simple morphophysiological dormancy, in which mechanical resistance of the pericarp-mesocarp envelope plays a key role in the initial physiological phase. Maximum parsimony analyses, including data obtained in the present work, indicate that morphophysiological dormancy is likely to be a pleisiomorphic trait in flowering plants. The significance of this conclusion for studies of early angiosperm evolution is discussed.
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morphophysiological dormancy in seeds of convallaria keiskei and a proposal to recognize two types of double dormancy in seed dormancy classification
Seed Science Research, 2015Co-Authors: Tetsuya Kondo, Shyam S Phartyal, Mizuki Narita, Siti N Hidayati, Jeffrey L Walck, Jerry M Baskin, Carol C BaskinAbstract:Convallaria majalis has double dormancy and hypogeal germination, but no information is available on Embryo Growth or on the effects of light and gibberellic acid (GA 3 ) on germination in this genus. Therefore, we investigated Embryo Growth and other germination features in seeds of C. keiskei and compared the data with those of Trillium camschatcense in another study. Until now, in seeds with double dormancy, Embryo Growth and germination (epigeal) have been studied in detail only for seeds of T. camschatcense . Phenology of Embryo Growth and emergence of cotyledonary petiole/root (hereafter root) and shoot in seeds of C. keiskei were monitored outdoors. Effects of temperature, light and GA 3 on Embryo Growth and root and shoot emergence were tested under laboratory conditions. Roots emerged the first spring following seed dispersal in autumn. The Embryo grew soon after root emergence, and germination was hypogeal. Seeds with an emerged root formed buds from which a shoot (leaf) emerged above ground during the second spring. Alternating temperatures and light had negative effects on root emergence, and GA 3 did not substitute for cold stratification in root emergence. Seeds of C. keiskei have double dormancy, but it differs from that in T. camschatcense . Based on differences in Embryo Growth before ( T. camschatcense ) versus after ( C. keiskei ) root emergence, and on epigeal ( T. camschatcense ) versus hypogeal ( C. keiskei ) germination, we suggest that two types of deep simple double morphophysiological dormancy (MPD) be recognized. Since Embryo Growth in C. keiskei does not fit the standard definition of MPD, we propose to expand this definition.
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intermediate complex morphophysiological dormancy in seeds of the cold desert sand dune geophyte eremurus anisopterus xanthorrhoeaceae liliaceae s l
Annals of Botany, 2014Co-Authors: Jannathan Mamut, Carol C Baskin, Dun Yan Tan, Jerry M BaskinAbstract:BACKGROUND AND AIMS Little is known about morphological (MD) or morphophysiological (MPD) dormancy in cold desert species and in particular those in Liliaceae sensu lato, an important floristic element in the cold deserts of Central Asia with underdeveloped embyos. The primary aim of this study was to determine if seeds of the cold desert liliaceous perennial ephemeral Eremurus anisopterus has MD or MPD, and, if it is MPD, then at what level. METHODS Embryo Growth and germination was monitored in seeds subjected to natural and simulated natural temperature regimes and the effects of after-ripening and GA3 on dormancy break were tested. In addition, the temperature requirements for Embryo Growth and dormancy break were investigated. KEY RESULTS At the time of seed dispersal in summer, the Embryo length:seed length (E:S) ratio was 0·73, but it increased to 0·87 before germination. Fresh seeds did not germinate during 1 month of incubation in either light or darkness over a range of temperatures. Thus, seeds have MPD, and, after >12 weeks incubation at 5/2 °C, both Embryo Growth and germination occurred, showing that they have a complex level of MPD. Since both after-ripening and GA3 increase the germination percentage, seeds have intermediate complex MPD. CONCLUSIONS Embryos in after-ripened seeds of E. anisopterus can grow at low temperatures in late autumn, but if the soil is dry in autumn then Growth is delayed until snowmelt wets the soil in early spring. The ecological advantage of Embryo Growth phenology is that seeds can germinate at a time (spring) when sand moisture conditions in the desert are suitable for seedling establishment.
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physiology morphology and phenology of seed dormancy break and germination in the endemic iberian species narcissus hispanicus amaryllidaceae
Annals of Botany, 2011Co-Authors: Elena Copete, Pablo Ferrandis, Jose M Herranz, Carol C Baskin, Jerry M BaskinAbstract:†Background and Aims Only very few studies have been carried out on seed dormancy/germination in the large monocot genus Narcissus. A primary aim of this study was to determine the kind of seed dormancy in Narcissus hispanicus and relate the dormancy breaking and germination requirements to the field situation. †Methods Embryo Growth, radicle emergence and shoot Growth were studied by subjecting seeds with and without an emerged radicle to different periods of warm, cold or warm plus cold in natural temperatures outdoors and under controlled laboratory conditions. †Key Results Mean Embryo length in fresh seeds was approx. 1.31 mm, and Embryos had to grow to 2.21 mm before radicle emergence. Embryos grew to full size and seeds germinated (radicles emerged) when they were warm stratified for 90 d and then incubated at cool temperatures for 30 d. However, the Embryos grew only a little and no seeds germinated when they were incubated at 9/5, 10 or 15/4 8C for 30 d following a moist cold pre-treatment at 5, 9/5 or 108C. In the natural habitat of N. hispanicus, seeds are dispersed in late May, the Embryo elongates in autumn and radicles emerge (seeds germinate) in early November; however, if the seeds are exposed to low temperatures before Embryo Growth is completed, they re-enter dormancy (secondary dormancy). The shoot does not emerge until March, after germinated seeds are cold stratified in winter. †Conclusion Seeds of N. hispanicus have deep simple epicotyl morphophysiological dormancy (MPD), with the dormancy formula C1bB(root) ‐ C3(epicotyl). This is the first study on seeds with simple MPD to show that Embryos in advanced stages of Growth can re-enter dormancy (secondary dormancy).
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morphological dormancy in seeds of the autumn germinating shrub lonicera caerulea var emphyllocalyx caprifoliaceae
Plant Species Biology, 2009Co-Authors: Shyam S Phartyal, Tetsuya Kondo, Yoichiro Hoshino, Jerry M Baskin, Carol C BaskinAbstract:To better understand the germination ecophysiology of the genus Lonicera, the dormancy class, temperature requirements for Embryo Growth and radicle emergence and phenology of seedling emergence were determined for Lonicera caerulea var. emphyllocalyx .A t maturity, seeds have an underdeveloped Embryo (approximately 28% of the length of full-grown Embryos). Embryos in fresh seeds grew to full length at 15, 20, 20/10 and 25/15°C within 3 weeks, but failed to grow at 10°C and at 30°C. Radicles emerged from 86–100% of freshly matured seeds in light at 15, 20, 20/10 and 25/15°C within 28 days, but failed to emerge at 10°C. Radicles emerged equally well in a 12 h photoperiod and in continuous darkness at 25/15°C. Rapid Embryo Growth and germination over a range of conditions indicate that seeds of this taxon have morphological dormancy (MD); this is the first report of MD in a species of Lonicera. Seeds are dispersed in summer, at which time high temperatures promote Embryo Growth. Embryos grow to the critical length for germination in approximately 1 month; the peak of seedling emergence occurs in early autumn. Radicles emerged within 2 months from 98% of seeds buried at soil depths of 2 cm and 10 cm in the field in August in Sapporo, Japan; thus, seeds have no potential to form a persistent soil seed bank. However, seeds sown too late in autumn for Embryos to grow remained viable and germinated the following summer when temperatures were high enough to promote Embryo Growth.
Mc Nautiyal - One of the best experts on this subject based on the ideXlab platform.
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Epicotyl morphophysiological dormancy in seeds of Lilium polyphyllum (Liliaceae)
2016Co-Authors: Anurag Dhyani, Shyam S Phartyal, Bp Nautiyal, Mc NautiyalAbstract:Dormancy-breaking and seed germination studies in genus Lilium reveal that the majority of Lilium spp. studied have an underdeveloped Embryo at maturity, which grows inside the seed before the radicle emerges. Additionally, the Embryo, radicle or cotyledon has a physiological component of dormancy; thus, Lilium seeds have morphophysio-logical dormancy (MPD). A previous study suggested that seeds of Lilium polyphyllum have MPD but the study did not investigate the development of the Embryo, which is one of the main criteria to determine MPD in seeds. To test this hypothesis, we investigated Embryo Growth and emergence of radicles and epicotyls in seeds over a range of temperatures. At maturity, seeds had underdeveloped Embryos which developed fully at warm temperature within 6 weeks. Immediately after Embryo Growth, radicles also emerged at warm temperatures. However, epicotyls failed to emerge soon after radicle emergence. Epicotyls emerged from>90 % seeds with an emerged radicle only after they were subjected to 2 weeks of cold moist stratification. The overall temperature requirements for dormancy-breaking and seed germination indicate a non-deep simple epicotyl MPD in L. polyphyllum. [Dhyani A, Phartyal SS, Nautiyal BP and Nautiyal MC 2013 Epicotyl morphophysiological dormancy in seeds of Lilium polyphyllum (Liliaceae). J. Biosci. 38 13–19] DOI 10.1007/s12038-012-9284-5 1
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Epicotyl morphophysiological dormancy in seeds of Lilium polyphyllum (Liliaceae)
Journal of Biosciences, 2012Co-Authors: Anurag Dhyani, Shyam S Phartyal, Bp Nautiyal, Mc NautiyalAbstract:Dormancy-breaking and seed germination studies in genus Lilium reveal that the majority of Lilium spp. studied have an underdeveloped Embryo at maturity, which grows inside the seed before the radicle emerges. Additionally, the Embryo, radicle or cotyledon has a physiological component of dormancy; thus, Lilium seeds have morphophysiological dormancy (MPD). A previous study suggested that seeds of Lilium polyphyllum have MPD but the study did not investigate the development of the Embryo, which is one of the main criteria to determine MPD in seeds. To test this hypothesis, we investigated Embryo Growth and emergence of radicles and epicotyls in seeds over a range of temperatures. At maturity, seeds had underdeveloped Embryos which developed fully at warm temperature within 6 weeks. Immediately after Embryo Growth, radicles also emerged at warm temperatures. However, epicotyls failed to emerge soon after radicle emergence. Epicotyls emerged from >90% seeds with an emerged radicle only after they were subjected to 2 weeks of cold moist stratification. The overall temperature requirements for dormancy-breaking and seed germination indicate a non-deep simple epicotyl MPD in L. polyphyllum.
Weidong Hao - One of the best experts on this subject based on the ideXlab platform.
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chlormequat chloride retards rat Embryo Growth in vitro
Toxicology in Vitro, 2016Co-Authors: Bayindala Xiagedeer, Yingjuan Liu, Weidong HaoAbstract:Chlormequat chloride is the most widely used plant Growth regulator in agriculture to promote sturdier Growth of grain crops by avoidance of lodging. Therefore, human exposure to chlormequat chloride is very common, but its developmental toxicity has not been studied. Thus, we investigated the developmental toxicity of chlormequat chloride by applying rat whole Embryo culture (WEC) model, limb bud micromass culture and 3T3 fibroblast cytotoxicity test. Chlormequat chloride at 150μg/ml (0.93mM) retarded the rat Embryo Growth without causing significant morphological malformations and at 500μg/ml (3.1mM) caused both retardation and morphological malformation of the Embryos. However, the proliferation and differentiation of limb bud cells were not affected by chlormequat chloride at as high as up to 1000μg/ml (6.2mM) applied. This concentration of chlormequat chloride did not affect the cell viability as examined by 3T3 fibroblast cytotoxicity test either, suggesting that cellular toxicity may not play a role in chlormequat induced inhibition of rat Embryo Growth. Collectively, our results demonstrated that chlormequat chloride may affect Embryo Growth and development without inhibiting cell viability.
Hao Weidong - One of the best experts on this subject based on the ideXlab platform.
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Chlormequat chloride retards rat Embryo Growth in vitro
TOXICOLOGY IN VITRO, 2016Co-Authors: Xiagedeer Bayindala, Wu Shuang, Liu Yingjuan, Hao WeidongAbstract:Chlormequat chloride is the most widely used plant Growth regulator in agriculture to promote sturdier Growth of grain crops by avoidance of lodging. Therefore, human exposure to chlormequat chloride is very common, but its developmental toxicity has not been studied. Thus, we investigated the developmental toxicity of chlormequat chloride by applying rat whole Embryo culture (WEC) model, limb bud micromass culture and 3T3 fibroblast cytotoxicity test. Chlormequat chloride at 150 mu g/ml (0.93 mM) retarded the rat Embryo Growth without causing significant morphological malformations and at 500 mu g/ml (3.1 mM) caused both retardation and morphological malformation of the Embryos. However, the proliferation and differentiation of limb bud cells were not affected by chlormequat chloride at as high as up to 1000 mu g/ml (6.2 mM) applied. This concentration of chlormequat chloride did not affect the cell viability as examined by 3T3 fibroblast cytotoxicity test either, suggesting that cellular toxicity may not play a role in chlormequat induced inhibition of rat Embryo Growth. Collectively, our results demonstrated that chlormequat chloride may affect Embryo Growth and development without inhibiting cell viability. (C) 2016 Elsevier Ltd. All rights reserved.National Natural Science Foundation of People's Republic of China [30771821]; National Key Technology Research and Development Program [2009ZX09301-010]SCI(E)PubMedARTICLEwhao@bjmu.edu.cn274-2823