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Nobuo Okagami - One of the best experts on this subject based on the ideXlab platform.
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expansion of trait of gibberellin induced dormancy in the Tertiary relict species of the genus dioscorea dioscoreaceae
Plant Growth Regulation, 1997Co-Authors: Nobuo Okagami, Noriaki Tanno, Massashi Kawai, Akira Hiratsuka, Kenichi Satoh, Keisuke TeruiAbstract:Effects of the application of gibberellin A3 (GA3) on sprouting of rhizomes and germination of seeds were tested in five species of the genus Dioscorea which are considered to be Tertiary relicts growing disjunctively in the Appalachians, the Balkans, and the Caucasus. Applied GA3 at higher than 1 micro;M markedly inhibited sprouting of rhizomes of all species. However, inhibition of seed germination of these species by GA3 application was not observed. It is hypothesized that before disjunction in the Tertiary Period GA-induced dormancy probably prevailed in rhizomes of all members of the genus Dioscorea.
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temperature effects on seed germination of east asian and Tertiary relict species of dioscorea dioscoreaceae
American Journal of Botany, 1993Co-Authors: Keisuke Terui, Nobuo OkagamiAbstract:To obtain information relevant to the evolution of dormancy, germination responses to temperature of intact seeds and naked zygotic embryos were compared among taxonomically closely related species of Dioscorea in the section Stenophora. We examined five species from the northern half of the East Asian distribution area and four species considered to be Tertiary relict species from the Appalachians, the Caucasus, and the Balkans. Although features of germination of the intact seeds differed from species to species, the naked embryos of all species germinated over a similar wide range of temperatures without any marked differences among species. This unitary physiological feature of the embryos suggests the possibility that the temperature responses of the embryos have not changed since the Tertiary Period. In the East Asian species, as the distribution area shifts to the north the seeds gradually lose their dormant features, and consequently the germination behavior of the seeds gradually changes to resemble that of their embryos. The seed of the northernmost species has no dormant features at all, and temperature responses of the seed are the same as those of the embryo. Full germination of the intact seeds of East Asian and Tertiary relict species required prior chilling treatment. Unlike the East Asian species, however, the relict species germinated to some extent at higher temperatures over a narrow range without prior chilling. However, the resultant germlings died or elongated poorly. Thus, the germination process of relict species may have become less sensitive to high-temperature inhibition after their isolation from Asian species.
Keisuke Terui - One of the best experts on this subject based on the ideXlab platform.
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expansion of trait of gibberellin induced dormancy in the Tertiary relict species of the genus dioscorea dioscoreaceae
Plant Growth Regulation, 1997Co-Authors: Nobuo Okagami, Noriaki Tanno, Massashi Kawai, Akira Hiratsuka, Kenichi Satoh, Keisuke TeruiAbstract:Effects of the application of gibberellin A3 (GA3) on sprouting of rhizomes and germination of seeds were tested in five species of the genus Dioscorea which are considered to be Tertiary relicts growing disjunctively in the Appalachians, the Balkans, and the Caucasus. Applied GA3 at higher than 1 micro;M markedly inhibited sprouting of rhizomes of all species. However, inhibition of seed germination of these species by GA3 application was not observed. It is hypothesized that before disjunction in the Tertiary Period GA-induced dormancy probably prevailed in rhizomes of all members of the genus Dioscorea.
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temperature effects on seed germination of east asian and Tertiary relict species of dioscorea dioscoreaceae
American Journal of Botany, 1993Co-Authors: Keisuke Terui, Nobuo OkagamiAbstract:To obtain information relevant to the evolution of dormancy, germination responses to temperature of intact seeds and naked zygotic embryos were compared among taxonomically closely related species of Dioscorea in the section Stenophora. We examined five species from the northern half of the East Asian distribution area and four species considered to be Tertiary relict species from the Appalachians, the Caucasus, and the Balkans. Although features of germination of the intact seeds differed from species to species, the naked embryos of all species germinated over a similar wide range of temperatures without any marked differences among species. This unitary physiological feature of the embryos suggests the possibility that the temperature responses of the embryos have not changed since the Tertiary Period. In the East Asian species, as the distribution area shifts to the north the seeds gradually lose their dormant features, and consequently the germination behavior of the seeds gradually changes to resemble that of their embryos. The seed of the northernmost species has no dormant features at all, and temperature responses of the seed are the same as those of the embryo. Full germination of the intact seeds of East Asian and Tertiary relict species required prior chilling treatment. Unlike the East Asian species, however, the relict species germinated to some extent at higher temperatures over a narrow range without prior chilling. However, the resultant germlings died or elongated poorly. Thus, the germination process of relict species may have become less sensitive to high-temperature inhibition after their isolation from Asian species.
Ergin Hamzaoglu - One of the best experts on this subject based on the ideXlab platform.
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ecology of Tertiary relict endemic liquidambar orientalis mill forests
Forest Ecology and Management, 2008Co-Authors: Munir Ozturk, Ali Celik, Aykut Guvensen, Ergin HamzaogluAbstract:Abstract The oriental sweetgum, Liquidambar orientalis Mill. is a Tertiary Period relict endemic taxon of the east Mediterranean. The flat deep hydromorphic soils rich in surface waters during summer months are the most productive sites for the dense stands of L. orientalis . It is mainly distributed on sandy soils, with an alkaline pH. The CaCO 3 content in the soils show a medium value and the percentage of total salt content is very low, but organic matter content is higher. The monoecious trees are on an average 15–20 m tall and form dense forests confined to floodplains, valleys and along streams and in a few dry habitats. The plant shows a typical leaf dimorphism with sparsely lobed leaves at the top and many lobed leaves on the lower parts. Fresh seeds germinate well and the percentage varies from 60 to 80. A syntaxonomical synthesis of these forests was carried out. All associations of L. orientalis including the newly defined Querco ilicis-Liquidambaretum orientalis association have been evaluated within the alliance Platanion orientalis Karpati & Karpati 1961. This alliance is included in the order Platanetalia orientalis Knapp 1959, and class Alno-populetea Knapp 1959.
Munir Ozturk - One of the best experts on this subject based on the ideXlab platform.
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ecology of Tertiary relict endemic liquidambar orientalis mill forests
Forest Ecology and Management, 2008Co-Authors: Munir Ozturk, Ali Celik, Aykut Guvensen, Ergin HamzaogluAbstract:Abstract The oriental sweetgum, Liquidambar orientalis Mill. is a Tertiary Period relict endemic taxon of the east Mediterranean. The flat deep hydromorphic soils rich in surface waters during summer months are the most productive sites for the dense stands of L. orientalis . It is mainly distributed on sandy soils, with an alkaline pH. The CaCO 3 content in the soils show a medium value and the percentage of total salt content is very low, but organic matter content is higher. The monoecious trees are on an average 15–20 m tall and form dense forests confined to floodplains, valleys and along streams and in a few dry habitats. The plant shows a typical leaf dimorphism with sparsely lobed leaves at the top and many lobed leaves on the lower parts. Fresh seeds germinate well and the percentage varies from 60 to 80. A syntaxonomical synthesis of these forests was carried out. All associations of L. orientalis including the newly defined Querco ilicis-Liquidambaretum orientalis association have been evaluated within the alliance Platanion orientalis Karpati & Karpati 1961. This alliance is included in the order Platanetalia orientalis Knapp 1959, and class Alno-populetea Knapp 1959.
Aykut Guvensen - One of the best experts on this subject based on the ideXlab platform.
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ecology of Tertiary relict endemic liquidambar orientalis mill forests
Forest Ecology and Management, 2008Co-Authors: Munir Ozturk, Ali Celik, Aykut Guvensen, Ergin HamzaogluAbstract:Abstract The oriental sweetgum, Liquidambar orientalis Mill. is a Tertiary Period relict endemic taxon of the east Mediterranean. The flat deep hydromorphic soils rich in surface waters during summer months are the most productive sites for the dense stands of L. orientalis . It is mainly distributed on sandy soils, with an alkaline pH. The CaCO 3 content in the soils show a medium value and the percentage of total salt content is very low, but organic matter content is higher. The monoecious trees are on an average 15–20 m tall and form dense forests confined to floodplains, valleys and along streams and in a few dry habitats. The plant shows a typical leaf dimorphism with sparsely lobed leaves at the top and many lobed leaves on the lower parts. Fresh seeds germinate well and the percentage varies from 60 to 80. A syntaxonomical synthesis of these forests was carried out. All associations of L. orientalis including the newly defined Querco ilicis-Liquidambaretum orientalis association have been evaluated within the alliance Platanion orientalis Karpati & Karpati 1961. This alliance is included in the order Platanetalia orientalis Knapp 1959, and class Alno-populetea Knapp 1959.